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FUEL CELL TEST SYSTEM

Scribner Associates Model 850C

OPERATING MANUAL

850C

READ ME FIRST Model 850C Installation Procedure

i

R E A D M E F I R S T

Model 850C Installation Procedure Rev. E, 10/2007

1. The following is required to install the Model 850C Fuel Cell Test System

a. Venting for exit gas from fuel cell Anode and Cathode

b. Gas supplies

Tanks with appropriate regulators, e.g., hydrogen (H2), oxygen (O2), air, and

nitrogen (N2) or other inert purge gas

Gas and water supply lines

o Important: Use stainless flex tubing or other flame/safe tubing for

hydrogen supply

Gas and water supply fittings – a minimum of four (4) 1/4 inch stainless steel

Swagelok fittings with plastic ferrules for plastic tubing and stainless ferrules

for stainless tubing

o Reactant and water connections to the 850C are made with 1/4 inch

stainless steel Swagelok fittings. For details and instructions on installing

and using Swagelok fittings see Appendix D, www.swagelok.com or

http://www.swagelok.com/downloads/webcatalogs/EN/MS-12-01.pdf

c. Power: 110-120 VAC, 50-60 Hz, 10 Amps minimum

If the available line voltage is not 110-120 VAC, 50-60 Hz, use a step-down

transformer to supply this voltage from mains supply. The transformer output

current rating must be at least that on the 850C rear panel current rating label.

Make sure that it has the correct North American connector for the 850C power

cord, including the safety earth ground pin

d. Water: Use ONLY ASTM Type I water (18 M-cm minimum resistivity)

Water supply pressure must be no more than 65 PSIG for all 850C models

Water supply pressure must be at least 30 PSIG for Auto Water Fill (AWF)

models

The humidifier tank may be filled and drained by gravity for models without

the AWF option. You can fill only the cathode tank if hydrogen is not used

(e.g., if using a liquid fuel) on models without the AWF option.

To add water to the tank while the system is running, the supply water pressure

must be greater than the backpressure of the system otherwise the tanks will

drain hot water into the supply. For models with the AWF option, supply

pressure must be at least 20 PSIG above the back pressure.

e. Host computer with USB port and Windows XP Pro/Vista/7/8 recommended

f. Tools

9/16 inch wrench

Philips screwdriver

g. Gas transfer lines

We do not recommend extending the length of the gas transfer lines with

additional tubing between the built-in insulated and heated transfer lines on the

850C and the fuel cell because of potential problems with cold spots and water

condensation. Any location along the gas flow path from the humidifier tank to

the cell that allows the gas to cool below its dew point will cause water

http://www.swagelok.com/



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condensation resulting in a decrease in humidity level, fluctuations in humidity

level, and formation of water droplets, all of which may negatively impact cell

performance, stability and reproducibility. If extending the gas transfer lines is

necessary, take extreme care to heat the lines above operating gas dew points.

2. Carefully unpack 850C Test System and inspect for visible damage

a. Save box and shipping materials for return shipment

3. Place 850C on prepared workbench space

a. Important: Avoid locating 850C near source of contamination and corrosive

chemicals such as in a fume hood

b. Approximate space requirements for 850C with Fuel Cell: 36 inch Length x 30 inch

Wide x 19 inch Height (91 cm L x 76 cm W x 48 cm H)

4. Attach MultiGas Selector to 850C (Option) - Skip to Step 5 if you do did not purchase

the MultiGas Selector Option

a. See separate MultiGas Selector Installation Procedure or Appendix E.

5. Connect Anode, Cathode, and Purge gas supply to 850C (see picture)

a. Important: Use stainless flex tubing or other flame/safe tubing for hydrogen supply


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6. Fill Anode and Cathode Humidifiers (models without AWF option)

a. Make sure that humidifier water fill valve (drain valve for models with AWF option)

is in OFF (Up) position (see picture)

b. Connect high-purity water (ASTM Type I, 18 M-cm) supply to Water Inlet located

on rear panel of 850C (see picture)

c. Remove protective black boots from Anode and Cathode gas lines located on the

front of the 850C

d. Use water fill valve to (see picture below):

i. Fill Cathode humidifier tank (Front Tank) to red stripe on sight glass as

seen through side panel window - Do NOT over fill

ii. Fill Anode humidifier tank (Rear Tank) to red stripe on sight glass as seen

through side panel window - Do NOT over fill

iii. Return water fill valve to the OFF (Up) position

Water fill

level

Water fill

level

7. Fill Anode and Cathode Humidifiers (models with AWF option)

Tanks will begin to fill automatically when power is turned on. Anode tank will fill

first, followed by cathode tank.

8. Host Computer (PC) Setup - Skip step “a” if you purchased a pre-configured PC

a. Install National Instruments NI-488.2 Driver Software (from included CD) on Host

PC

See NI GPIB Installation Guide for instructions

b. Connect USB-GPIB adapter cable to a USB port on the Host PC

It is very important to install the NI drivers before connecting the USB-GPIB

adaptor to the Host PC

c. Connect USB-GPIB adaptor to the 850C GPIB interface (see picture)

d. Note: Factory default GPIB address is 7


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9. Install FuelCell® Software from the Scribner Associates, Inc. CD-ROM

a. Put CD in Host PC CD-ROM drive and follow installation instructions

b. Note: Information about your 850C required during the software installation is

indicated on the serial number plate on the 850C back panel

Serial number

Load capacity: Power (in Watts), Current (in Amps), and Voltage (in Volts),

e.g., 50W/50A/20V

Anode and Cathode Mass Flow Controllers (in standard cubic centimeters per

minute, sccm), e.g., 1000 / 2000 sccm

10. Connect the Fuel Cell to 850C

a. Important Notes:

The following installation procedure is for a typical Polymer Electrolyte

Membrane (PEM) fuel cell using gaseous reactants on both the anode and

cathode and for common single-cell hardware

Cell hardware different from the one used here may require a slightly different

installation procedure due to cell hardware-specific load and sense lead

attachment locations, heaters, isolated vs. non-isolated end-plates, etc.

If installing a Direct Methanol Fuel Cell (DMFC) or fuel cell using a liquid

fuel, follow the DMFC and Liquid Fueled Fuel Cell Installation Instructions

d. Place Fuel Cell fixture in front of 850C

e. Connect Anode and Cathode gas line from 850C to Fuel Cell (see below left)

Use plastic (Nylon) Swagelok ferrules

Important: Take care to avoid damaging the 850C gas lines by, for example,

over-tightening the Swagelok fitting

When using gas reactants, the reactants enter at the top of the fuel cell and exit

on the bottom of the fuel cell on both the Anode and Cathode. This allows

gravity to assist in removing water from the cell. Connecting the cell so that

the reactants enter the cell at the bottom and exit the cell at the top can lead to

severe water flooding

d. Connect Anode and Cathode fuel cell gas exit ports to vents (see below right) or

850BP Back Pressure Unit (Option)


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Gas Inlet

Gas Outlet

Anode

(Fuel Side)

Cathode

(Air / O2 Side)

Gas Inlet

Gas Outlet

Anode

(Fuel Side)

Cathode

(Air / O2 Side)

e. Connect Load Cables to Fuel Cell (see picture) using the stainless steel bolts and

nuts

Important: Observe proper polarity

o Anode (hydrogen / fuel side) is Negative (–)

o Cathode (Air or Oxygen side) is Positive (+)

f. Connect labeled Sense Leads to Fuel Cell Current Collector Plates (see picture)

Important: Observe proper polarity:

o Whole – (Black) to Anode (Hydrogen / Fuel) side of cell

o Whole + (Red) to Cathode (Air / Oxygen) side of cell

Half Cell (White and Green) leads are not used unless using Reference

Electrode(s)

g. Connect Fuel Cell type T (blue) thermocouple to 850C Cell Thermocouple jack (see

picture)

Insert the thermocouple in the fuel cell if not already present

h. Connect Fuel Cell Heater power to 850C Cell Heater Receptacle (see picture)


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11. Turn on Anode, Cathode and Purge gas supply

a. Minimum Pressure 45 PSIG, Maximum Pressure 60 PSIG

b. Important: Check for gas leaks at all connections and fittings

12. Attach power cord to back of 850C and plug into AC power

120 VAC 60 Hz, 10 Amp minimum rating

13. If not already ON, turn on and boot PC but do NOT start FuelCell® software yet

a. If FuelCell® is running, exit the program before turning on the 850C power

14. Press and Release Emergency Stop Switch located on the front of the 850C

15. Turn the 850C Power switch ON

a. Note: Cell reactant supply lines will begin to heat when the 850C is turned ON

b. The three (3) Temperature Controllers on the front of the 850C (Anode Fuel Temp,

Cathode Fuel Temp, and Cell Temp) should read:

Present Value (PV) near ambient temperature

Set Value (SV) default to 15 (in °C) until the FuelCell® software is started and

the Apply Temp button activated (see FuelCell® manual for software

instructions)

16. On Host PC, start FuelCell® software and follow normal operating procedures

a. See FuelCell® software manual for instructions for additional information

Model 850C Fuel Cell Test System

©Copyright 1996 - 2007

Scribner Associates, Inc.

Southern Pines, North Carolina

All rights reserved. No part of this publication may be reproduced, transmitted, transcribed, stored

on a retrieval system or translated into any language, in any form or by any means, electronic,

mechanical, manual or otherwise, without the prior written consent of Scribner Associates, Inc.

Scribner Associates Inc. makes no representations or warranties with respect to the contents hereof

and specifically disclaims any implied warranties of merchantability and fitness for a particular

purpose. Furthermore, Scribner Associates, Inc. reserves the right to revise this publication and to

make changes from time to time in the content hereof without obligation to notify any person of

such revision or changes.

Safety

It is required that this equipment and software be operated and maintained only by

trained and qualified persons familiar with fuel cell technology and safe laboratory

techniques. All users should have adequate training and knowledge of the hazards associated

with the use of pressurized flammable gasses and all applicable laboratory techniques before

operation of this equipment.

Model 850C

Fuel Cell Test System

FUEL CELL TEST SYSTEM

OPERATING MANUAL


150 E. Connecticut Ave.

Southern Pines, North Carolina, USA 28387

Phone: 910-695-8884, Fax: 910-695-8886

e-mail: [email protected]

support: [email protected]

web site: www.scribner.com Revised: 3/2007

READ ME FIRST Model 850C Installation Procedure …………...…………..…………….i

CHAPTER 1 .................................................................................................................................. 1

INTRODUCTION AND SAFETY .............................................................................................. 1

1.1. System Requirements .............................................................................................. 2

1.2. Technical Support .................................................................................................... 2

1.3 Chapter Summaries ................................................................................................. 3

1.4 Using This Manual ................................................................................................... 3

1.4.1 Hardware ................................................................................................ 3

1.5 Safety Precautions.................................................................................................... 4

1.5.1 General .................................................................................................... 4

1.5.2 Material Safety Data Sheets .................................................................. 4

1.5.3 Hydrogen Safety ..................................................................................... 4

1.5.5 Grounding............................................................................................... 4

1.5.6 AC Supply Voltage................................................................................. 4

1.5.7 Fuses ........................................................................................................ 5

1.5.8 Avoid Unsafe Equipment ...................................................................... 5

1.5.9 Live Conductors ..................................................................................... 5

1.5.10 Equipment Modification ....................................................................... 5

CHAPTER 2 .................................................................................................................................. 7

SAFETY ......................................................................................................................................... 7

2.1 General ........................................................................................................................ 7

2.2 Material Safety Data Sheets ...................................................................................... 7

2.3 Flammable and Oxidizing Gases .............................................................................. 7

2.3.1 Gas Concentration within the Flammable Range ............................... 7

2.3.2 Ignition Source ....................................................................................... 8

2.3.3 Oxidizing Gases ...................................................................................... 8

2.4 Hydrogen Safety ......................................................................................................... 9

2.5 Computer Control and System Safety ................................................................... 12

2.6 Grounding ................................................................................................................. 12

2.7 AC Supply Voltage ................................................................................................... 12

2.8 Fuses .......................................................................................................................... 12

2.9 Avoid Unsafe Equipment ........................................................................................ 12

2.10 Live Conductors ..................................................................................................... 13

2.11 Equipment Modification ....................................................................................... 13

CHAPTER 3 ................................................................................................................................ 15

SYSTEM SPECIFICATIONS .................................................................................................. 15

AND HARDWARE INSTALL .................................................................................. 15

3.1 General Description ................................................................................................. 15

3.2 Specifications ............................................................................................................ 15

3.2.1 Standard 850C Models Available ......................................................... 15

3.2.2 AC Power Requirements ....................................................................... 16

3.2.3 Physical ................................................................................................... 16

3.3 Description of Controls and Connections ............................................................ 16

3.3.1 Front Panel ............................................................................................. 16

TABLE OF CONTENTS

3.3.2 Rear Panel .............................................................................................. 19

3.4 GPIB Board .............................................................................................................. 20

3.4.1 Electrical Connections ........................................................................... 21

3.4.2 GPIB Connections.................................................................................. 21

3.5 Fuel Cell Test Fixture .............................................................................................. 22

CHAPTER 4 ................................................................................................................................ 25

SYSTEM COMPONENTS AND CONFIGURATION ........................................................... 25

4.1 Basic System Components and their Descriptions ................................................ 25

4.1.1 Fuel Source, mass flow control and humidification............................ 25

4.1.2 Electronic Load ...................................................................................... 25

4.1.3 Data Acquisition ..................................................................................... 26

4.1.4 System Software ..................................................................................... 26

4.2 Fuel Source System Configuration ......................................................................... 26

4.2.1 Humidified Reactants, Hydrogen and Oxygen and/or Air ............... 26

CHAPTER 5 ................................................................................................................................ 29

GETTING STARTED AND OPERATION ............................................................................. 29

5.1 Preparation of Fuel, Gas and Electrical Connections .......................................... 29

5.2 Check List Before Proceeding: ............................................................................... 30

5.3 Apply AC Power ...................................................................................................... 30

5.3 Storage and Shipping ............................................................................................... 30

CHAPTER 6 ................................................................................................................................ 31

850C DETAILED SPECIFICATIONS ..................................................................................... 31

6.1 General Features ...................................................................................................... 31

6.2 Model 850C Hardware Specifications .................................................................... 31

APPENDIX A .............................................................................................................................. 35

TROUBLESHOOTING ............................................................................................................. 35

Communication Problems ............................................................................................. 35

APPENDIX B .............................................................................................................................. 37

USING THE AUXILIARY SIGNALS CONNECTOR ........................................................... 37

APPENDIX C .............................................................................................................................. 41

USING A PERISTALTIC PUMP FOR TESTING OF LIQUID FUELED FUEL CELLS 41

Setup of Pump ................................................................................................................. 41

Determination of Flow Rate ........................................................................................... 41

Configuring FuelCell software....................................................................................... 41

Setting Up the Pump ....................................................................................................... 42

Connecting Hardware .................................................................................................... 42

Using FuelCell with the Pump ....................................................................................... 43

APPENDIX D .............................................................................................................................. 45

SWAGELOK® TUBE FITTING INSTRUCTIONS ............................................................... 45

Part D1. Assembly Instructions for Standard Swagelok® Metal Tube Fittings ........ 46

Installation in High-Pressure Applications and High Safety-Factor Systems .......... 46

Gageability ....................................................................................................................... 46

Reassembly Instructions ................................................................................................. 47

Part D2. Swagelok®

PFA Fittings for Heated Gas Delivery Lines ............................. 48

APPENDIX E .............................................................................................................................. 49

MULTIGAS VALVE INSTALLATION PROCEDURE ........................................................ 49

Chapter 1 Introduction and Safety

1

CHAPTER 1

INTRODUCTION AND SAFETY

This manual describes the installation, configuration, and operation of the model 850C

fuel cell test systems. The combination of this hardware and software provides a complete

system for testing the characteristics and operating parameters of various types of fuel cells.

The model 850C Fuel Cell Test System (FCTS) provides a high level of real-time control

and safety monitoring using advanced hardware design. The model 850C FCTS is designed to

control or monitor virtually all of the parameters of an operating proton-exchange membrane

(PEM) type fuel cell or cell stack. The 850C also provides humidification and mass flow control

of reactant gasses, performs a variety of experiments and may be used with DMFC or SOFC type

cells by using a Methanol pump (DMFC) or external furnace and controls (SOFC).

With the model 850C and FuelCell® software you can:

Control the purge and fuel reactant gas streams for a fuel cell.

Control fuel gas humidification temperatures and fuel cell assembly temperature.

Scale fuel cell parameters for area, current, potential, power, and number of cells.

Apply and control a current, voltage, or power load on the fuel cell under test.

Monitor performance over a wide range of time intervals.

Display data using a wide variety of axis formats.

Assess fuel cell performance through cell resistance and Tafel slope measurement.

Apply a controlled load sequence to a cell to simulate varying operating conditions.

Save data files and experimental setup parameters.

Optimize experimental parameters for maximum measurement capability.

With the optional 880 FRA, fuel cell resistance (HFR) and impedance (EIS) can be

measured at a wide range of operating currents and conditions.

Control optional reformate gas mixing hardware.


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1.1. System Requirements

Model 850C Compact Fuel Cell Test System

Reactant and purge gas supplies – H2, N2 and O2/Air

Fuel cell test fixture with heater and thermocouple

National Instruments USB to GPIB adapter

FuelCell® Software for Windows

IBM PC/compatible computer -

Minimum Requirements

Pentium or equal processor

Windows XP Pro/Vista/7/8

256 Meg RAM

10 GB available hard disk space - data file dependent

1.2. Technical Support

Please review the Installation and Start Up portions of this manual prior to calling for

support. Users of FuelCell® Software can receive technical assistance through the following

sources:

Contact your sales agent or the factory.


150 E. Connecticut Ave.

Southern Pines, North Carolina, USA 28387

Telephone: 910-695-8884

Fax: 910-695-8886

Or Technical Support at:

Phone: 910-695-8884

e-mail: [email protected]

mailto:[email protected]


3

1.3 Chapter Summaries

CHAPTER 1. INTRODUCTION AND SAFETY

Provides an overall description of FuelCell Test System and the associated safety considerations

CHAPTER 2. SAFETY

Describes the uses of the Material Safety Data Sheets, OSHA Regulation, Computer Control, and

the Hazard Communication Standard pertaining to fuel cell safety

CHAPTER 3. LOAD SPECIFICATIONS AND HARDWARE INSTALLATION

Explains how to install and connect all the necessary hardware including the USB to GPIB cable

and drivers, the model 850C fuel cell test system, and the fuel cell test fixture electrical

connections

CHAPTER 4. SYSTEM COMPONETS AND CONFIGURATION

Describes the 850C Fuel Cell Test System basic components (Reactant gas control, Electrical

Power, Data Acquisition, and Test System Software)

CHAPTER 5. GETTING STARTED AND OPERATION

Steps the user through start-up of the fuel cell test hardware and discusses setting parameters,

system operating procedures, and taking measurements with a fuel cell

CHAPTER 6. 850C DETAILED SPECIFICATIONS

Describes the Model 850C Fuel Cell Test System and its specifications

APPENDIX A. TROUBLESHOOTING

Provides solutions for common connection, startup, and operation problems

APPENDIX B. USING THE AUXILIARY SIGNALS CONNECTOR

Describes settings and use of the auxiliary signals connector

APPENDIX C. USING A PERISTALTIC PUMP FOR TESTING OF LIQUID FUELED

FUEL CELLS

Discusses installation, set-up and use of a computer controlled pump for fuel cell testing with

liquid fuels

APPENDIX D. SWAGELOK® TUBE FITTING INSTRUCTIONS

Describes installation procedure and use of Swagelok fittings for reactant and high-purity water

supply

APPENDIX E. MULTIGAS VALVE INSTALLATION PROCEDURE

Detailed installation instructions for the optional multigas valve selector

1.4 Using This Manual

1.4.1 Hardware

Chapter 2 provides information on the installation of the National Instruments USB to GPIB

cable and its connection to the load unit as well as the model 850C Fuel Cell Test System itself.


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1.5 Safety Precautions

1.5.1 General

It is required that this equipment and software be operated and maintained only by

trained and qualified persons familiar with fuel cell technology and safe laboratory

techniques. All users should have adequate training and knowledge of the hazards

associated with the use of pressurized flammable gasses and all applicable laboratory

techniques before operation of this equipment.

The equipment and software described in this manual is supplied in a safe condition. To

avoid injury to an operator, the safety precautions, given below and throughout the manual, must

be strictly adhered to whenever the equipment is operated, serviced or repaired. For specific

safety details, please refer to the relevant sections within the manual.

This equipment is designed solely for electronic measurement on an operating fuel cell

and should not be used for any other purpose. Scribner Associates accepts no responsibility for

accidents or damage resulting from any failure to comply with these precautions.

1.5.2 Material Safety Data Sheets

It is strongly recommended that ALL applicable material safety data sheets be read and

understood for the protection of the operator. It is also recommended that due caution be used

during all testing procedures. Although safety measures have been applied internally to the fuel

cell test station, there are several regulations that may apply to a lab which uses highly

flammable, high pressure gases. It is suggested that a lab structure be used that is not only safe

but complies with the Occupational Safety and Health Administration’s (OSHA) regulations for

high pressure gases and flammable materials.

1.5.3 Hydrogen Safety

Use extreme caution during all testing procedures that use hydrogen gas.

1.5.5 Grounding

The equipment described in this manual relies on the connection of a protective

conductor to earth ground for equipment and operator safety. The power cable of the equipment

should only be inserted into an outlet that has the required earth ground contact. This protection

must not be disabled through the use of a two-conductor extension cord, an adaptor that does not

maintain earth ground continuity, or any other type of connection that does not maintain earth

ground continuity.

1.5.6 AC Supply Voltage


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Before first connecting the power to the equipment, make sure that the line voltage is

between 100 and 120 Volts, 50 or 60 Hertz. Never operate the equipment from a line voltage or

frequency in excess of that specified. Locate the equipment such that access to the power switch

(located on the front panel) is not obstructed.

WARNING! The equipment will be damaged by the application of incorrect line voltage.

DANGER! Voltage and current conditions inside the equipment described in this manual are

sufficient to cause injury and possibly death. Only qualified technicians should be

permitted to remove the cover or attempt repairs.

1.5.7 Fuses

Before switching on the equipment, check that the fuse accessible from the exterior of the

equipment is of the correct rating. The rating of the AC line fuse must accord with the value

stated in the specifications. Refer to Section 3.3.2 Rear Panel, “AC Power Input”

1.5.8 Avoid Unsafe Equipment

The equipment may be unsafe if any of the following statements apply:

Equipment shows visible damage.

Equipment has failed to perform properly.

Equipment has been subjected to prolonged storage under unfavorable conditions.

If there is any doubt as to the serviceability of the equipment, do not use it. Get it properly

checked out by a qualified service technician. If this equipment is used in a manner not specified

by Scribner Associates, the safety protection provided by the equipment may be impaired.

1.5.9 Live Conductors

Opening the cover or removing parts from this equipment could expose live conductors.

The equipment must be disconnected from all power and signal sources before it is opened for

any adjustment, replacement, maintenance or repair. Adjustments, maintenance or repair must

be done only by a qualified technician. Contact the factory for service information.

1.5.10 Equipment Modification

To avoid introducing safety hazards, never install non-standard parts in the equipment or

make any unauthorized modification. To maintain safety, always return the equipment to

Scribner Associates for service and repair.


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Chapter 2 Safety

7

CHAPTER 2

SAFETY

IMPORTANT SAFETY NOTICE

Users of this equipment should review all of the following material and other safety

standards deemed appropriate and apply all safety standards that may be required in the

user’s facility before proceeding. Safe operation of a fuel cell is the responsibility of the end

user of this equipment and may not be limited to the items below.

2.1 General

It is required that this equipment be operated only by trained and qualified persons

familiar with fuel cell technology and safe laboratory techniques. All users should have

adequate training and knowledge of the hazards associated with the use of pressurized

flammable gasses and all applicable laboratory techniques before operation of this

equipment.

The equipment described in this manual is supplied in a safe condition. To avoid injury

to an operator, the safety precautions given below and throughout the manual, must be strictly

adhered to whenever the equipment is operated. For specific safety details, please refer to the

relevant sections within the manual.

The equipment is designed solely for electronic measurement of an operating fuel cell

and should not be used for any other purpose. Scribner Associates accepts no responsibility for

accidents or damage resulting from any failure to comply with these precautions.

2.2 Material Safety Data Sheets

It is recommended that all applicable material safety data sheets (MSDS) be read and

understood for protection. In the United States, the law requires that the vendor provide a MSDS

with each chemical material sold. MSDS are a required part of hazardous material handling.

2.3 Flammable and Oxidizing Gases Flammable gases can burn or explode under certain conditions. Flammable gases include

acetylene, butane, ethylene, hydrogen, methylamine and vinyl chloride.

2.3.1 Gas Concentration within the Flammable Range

The concentration of the gas in air (or in contact with an oxidizing gas) must be between

its lower flammable limit (LFL) and upper flammable limit (UFL). The LFL and UFL are

sometimes called the lower and upper explosive limits (LEL and UEL), respectively. The LFL of

hydrogen gas in air is 4% and its UFL is 75% at atmospheric pressure and temperature. This

Chapter 2 Safety

8

means that hydrogen can be ignited when its concentration in the air is between 4% and 75%. A

hydrogen concentration below 4% is too lean to burn whereas above 75% it is too rich to burn.

The flammable range of a gas includes all of its concentrations in air between the LFL

and UFL. The flammable range of a gas is widened in the presence of oxidizing gases such as

oxygen or chlorine, and by higher temperatures or pressures. For example, the flammable range

of hydrogen in oxygen gas is 4% to 85% and the flammable range of hydrogen in chlorine gas is

4% to 89%.

2.3.2 Ignition Source

For a flammable gas within its flammable limits in air (or other oxidizing gas) to ignite,

an ignition source must be present. There are many possible ignition sources in most workplaces

including open flames, sparks and hot surfaces.

The auto-ignition or ignition temperature of a gas is the minimum temperature at which

the gas self-ignites without any obvious ignition sources. Some gases have very low auto-

ignition temperatures. For example, phosphine's auto-ignition temperature of 100 °C (212 °F) is

low enough that it could be ignited by a steam pipe or a lit light bulb.

Flash-back can occur with flammable gases. Many flammable compressed gases are

heavier than air. If a cylinder leaks in a poorly ventilated area, these gases can settle and collect

in sewers, pits, trenches, basements or other low areas. The gas trail can spread far from the

cylinder. If the gas trail contacts an ignition source, the fire produced can flash back to the

cylinder.

2.3.3 Oxidizing Gases

Oxidizing gases include any gases containing oxygen at higher than atmospheric

concentrations (above 23% to 25%), nitrogen oxides, and halogen gases such as chlorine and

fluorine. These gases can react rapidly and violently with combustible materials such as,

organic (carbon-containing) substances such as most flammable gases, flammable and

combustible liquids, oils, greases, many plastics and fabrics

finely-divided metals

other oxidizable substances such as hydrazine, hydrogen, hydrides, sulfur or sulfur

compounds, silicon and ammonia or ammonia compounds.

Fires or explosions can result.

The normal oxygen content in air is 21%. At slightly higher oxygen concentrations, for

example 25%, combustible materials, including clothing fabrics, ignite more easily and burn

much faster. Fires in atmospheres enriched with oxidizing gases are very hard to extinguish and

can spread rapidly.

Oxygen gas is a strong oxidizer and strongly increases the combustion of flammable

materials.

Table 1 summarizes the hazard ratings for gases commonly used for fuel cell testing.

Chapter 2 Safety

9

Table 1. NFPA hazard ratings for common gases.

Health (Blue)

Flammability (Red)

Instability or Reactivity (Yellow)

Special Fire-Related

Notices (White)

Nitrogen (N2) Gas 1 0 0

Oxygen (O2) Gas 0 0 0 OX

Gaseous Air 0 0 0

Hydrogen (H2) Gas 0 4 0

Carbon monoxide (CO) Gas

3 4 0

Carbon dioxide (CO2) Gas 1 0 0

2.4 Hydrogen Safety

It is recommended that extreme caution be used during all testing procedures that use

hydrogen gas. The information below is provided to assist in proper handling of hydrogen as part

of a fuel cell test program:

Chapter 2 Safety

10

General - PEM Fuel Cell

An emergency procedures list should be formulated and posted at the test station location

providing information on the location of the hydrogen shut off valves, responsible individuals,

and other pertinent information.

Install a hydrogen vent line from the fuel gas unit as required by local codes.

Place nonflammable barrier, such as a metal sheet, between fuel cell and bench top unless

surface is rated "flame retardant."

To prevent thermal burns:

Unplug heater connector at front panel before removing cartridges from fuel cell.

Allow fuel cell to cool below 40 °C before handling.

Be aware of the scenario of reactant gas crossover through the membrane, especially because

of differential operating pressures. With a pressure differential, hydrogen will back-stream up

the cathode line and into the humidity bottle forming an explosive mixture that catalytically

ignites from the fuel cell electrodes.

Hazards and Precautions

Properties of Hydrogen. Hydrogen is a colorless, odorless, tasteless, flammable,

nontoxic gas. It is the lightest of all gases, with a specific gravity of 0.0695. The hydrogen

content of atmospheric air at sea level is 0.5 ppm. Hydrogen has two isomers (forms): ortho-

hydrogen, in which the two atomic nuclei spin in the same direction; and para-hydrogen, in

which they spin in opposite directions. There is no difference in the chemical properties of the

two forms of hydrogen, but there are slight differences in physical properties. Gaseous hydrogen

is a mixture of 75% ortho-hydrogen and 25% para-hydrogen at room temperature; this mixture is

called normal hydrogen.

Because of its small molecular size, hydrogen can easily pass through porous materials

and is capable of leaking from a delivery system that effectively contains other gases. Hydrogen

is also capable of dissolving in and slowly diffusing through metals at room temperature. This

process is accelerated at elevated temperatures.

Hydrogen burns with a nearly invisible bluish flame, unless it is contaminated with

impurities. The temperature of burning hydrogen in air is high (3,718ºF), and warm hydrogen gas

rises rapidly because of its buoyancy. Hydrogen forms a flammable mixture over a wide range of

concentrations in air and requires a minimum ignition source, only one-tenth of the energy

required for gasoline vapors. It is the combination of these factors that contributes to the

flammability hazard associated with hydrogen gas. (See Table 2 for a summary of the physical

properties of hydrogen.)

Hydrogen is capable of being absorbed by some containment materials, which can result

in loss of ductility or embrittlement. At elevated temperatures, this process is accelerated.

Chapter 2 Safety

11

Because of the possibility of hydrogen embrittlement, piping and component materials that are

not subject to this form of degradation should be selected.

Table 2. Physical Properties and Characteristics of Hydrogen (values are approximate).

Color None

Odor None

Toxicity Nontoxic

Density, gas @ 1 atm, 0 °C 0.0899 g/L (0.0056 lb/ft3)

Density, liquid (boiling point) 0.07 g/cm3 (4.4 lb/ft

3)

Boiling point @ 1 atm (14.7 psia) -252.9 °C (-423.2 °F)

Critical temperature @ 12.8 atm. (188.2 psia) -240.2 °C (-400.4 °F)

Stoichiometric mixture in air 29 vol. %

Flammability limits in air 4 to 75 vol. %

Detonation limits in air 18 to 60 vol. %

Minimum ignition energy in air 20 mJ

Auto-ignition temperature 585 °C (1,085 °F)

Volume expansion:

liquid (-252.9 °C) to gas (-252.9°C) 1:53

gas (from -252.9 °C to 20 °C) 1:16

liquid (-252.9 °C) to gas (20 °C) 1:848

Physical Hazards The primary physical hazard associated with hydrogen gas is its

flammability and combustibility. This is because hydrogen can form an explosive mixture with

air over a wide range of concentrations (4 to 75 vol.%), and very low energy is needed to ignite

hydrogen-air mixtures. Once hydrogen is ignited, the reaction can proceed either by deflagration

(subsonic propagation) or detonation (supersonic propagation). Deflagration in a closed volume

can cause a pressure increase of almost eight times the initial pressure. Detonation from a low-

energy ignition source is possible in hydrogen-air mixtures of 18 to 60 vol. % that are well mixed

and confined. Although hydrogen-air mixtures have the same calorific value per pound as TNT,

the rate of energy release is much slower for hydrogen-air mixtures. Hydrogen detonations,

although rare, are characterized by pressure increases so rapid that pressure relief devices are

usually ineffective. When using hydrogen in enclosed areas, consult National Fire Protection

Association documents 68 and 69.

Health Effects The primary health effect associated with hydrogen is the possibility that

it could displace air in a poorly ventilated or confined space, resulting in asphyxiation. However,

because it is flammable at only 4 vol. % in air, the most significant concern should be the

physical hazard of flammability and the possibility of burns resulting from fires and explosions.

When working with liquid hydrogen, there is an additional health hazard of cryogenic burns.

Fuel System Design The fuel system used in the model 850C is designed for safe

operation with hydrogen gas as well as compliance with OSHA and other applicable regulations.

Hydrogen gases and Fuel Systems must be operated and handled by trained personnel in

accordance with applicable regulations

Chapter 2 Safety

12

2.5 Computer Control and System Safety

Precautions should be taken to ensure sustained operation of the PC controlling the model

850C. The use of an uninterruptible power supply is recommended to ensure continuous

electrical power to the PC used for the test system. If the electronics lose main power, an

automatic shutdown of the load and fuel will result. The user should evaluate the operation and

safety of the whole test system in the user’s lab before running any long term or unattended tests.

2.6 Grounding

The equipment described in this manual relies on the connection of a protective

conductor to earth ground for equipment and operator safety. The power cable of the equipment

should only be inserted into an outlet that has the required earth ground contact. The protection

must not be disabled through the use of a two-conductor extension cord, an adaptor that does not

maintain earth ground continuity, or any other type of connection that does not maintain earth

ground continuity. The ground prong of the power cable must not be cut off or otherwise

modified.

2.7 AC Supply Voltage

Before first connecting the power to the equipment, make sure that the line voltage is 100

to 120 Volts, 50 or 60 Hertz. Never operate the equipment from a line voltage or frequency other

than that specified. Locate the equipment such that access to the power switch (located on the

front panel) is not obstructed.

WARNING! The equipment may be damaged by the application of incorrect line voltage.

DANGER! Voltage and current conditions inside the equipment described in this manual are

sufficient to cause injury and possibly death. Only qualified technicians should be

permitted to remove the cover, attempt repairs, or connect the unit to the external

gas distribution equipment.

2.8 Fuses

Before switching on the equipment, check that the fuse accessible from the exterior of the

equipment is of the correct rating. The rating of the AC line fuse must accord with the value

stated in the specifications. Refer to Section 3.3.2 Rear Panel, “AC Power Input”

2.9 Avoid Unsafe Equipment

The equipment may be unsafe if any of the following statements apply:

Equipment shows visible damage.

Chapter 2 Safety

13

Equipment has failed to perform properly.

Equipment has been subjected to prolonged storage under unfavorable conditions.

If there is any doubt as to the serviceability of the equipment, do not use it. Get it properly

checked out by a qualified service technician. If this equipment is used in a manner not specified

by Scribner Associates, the safety protection provided by the equipment may be impaired.

2.10 Live Conductors

Opening the cover or removing of parts from this equipment could expose live

conductors. The equipment must be disconnected from all power and signal sources before it is

opened for any adjustment, replacement, maintenance, or repair or when gas distribution wiring

will be exposed. Adjustments, maintenance, or repair must be done only by a qualified

technician.

2.11 Equipment Modification

To avoid introducing safety hazards, never install non-standard parts in the equipment, or

make any unauthorized modification. To maintain safety, always return the equipment to

Scribner Associates for service and repair.

Chapter 2 Safety

14

Chapter 3 System Specifications and Hardware Installation

15

CHAPTER 3

SYSTEM SPECIFICATIONS

3.1 General Description

This chapter lists the specifications of the model 850C. It describes the operation and

installation of the National Instruments drivers and USB to GPIB adaptor cable for your

IBM/compatible PC and the electrical connections used to connect the Fuel Cell Test System to

the fuel / purge gas supplies and the fuel cell fixture hardware.

3.2 Specifications

The model 850C Fuel Cell Test System is a complete test station for operation and

measurement of PEM fuel cells. The 850C combines a computer-controlled instrument

(programmable electronic load, fuel and temperature controls, and data acquisition functions)

with humidifiers, mass flow controllers, and other fuel handling hardware in an integrated and

compact bench-top unit.

The 850C has a high performance fuel handling system that features: Anode and cathode

reactant gas flow paths, safety alarms, automatic purge with solenoid valves, insulated and

heated fuel cell supply hoses, high quality mass flow controllers, two highly efficient humidifiers

with low water alarms, and check valves to prevent system contamination.

The 850C and FuelCell® software permit long term performance testing of a fuel cell or

a small stack under user defined constant or varying conditions, coupled with real time

monitoring of the fuel cell and half cell potentials, iR corrected whole and half cell potentials,

current, power, half and whole cell internal resistances, fuel flow rates, and cell and fuel source

temperatures. Optional equipment includes backpressure regulation to 30 PSIG, integrated FRA

for EIS and HFR measurement, and a pump for DMFC testing.

3.2.1 Standard 850C Models Available

The ratings given below are for nominal fuel cell outputs. Note that fuel cell open circuit

voltages must fall within the maximum voltage ratings of the available 850C loads.

Model Max. Current Max. Power Max. Voltage Cooling Method 850C

850C-100A

5, 15, 25 or 50A*

100A

50 Watts

100Watts

20 V

20 V

Air

Air

* Current range must be selected at the time of purchase.


16

3.2.2 AC Power Requirements

100-120V AC 50-60 Hz, 10 Amps maximum.

3.2.3 Physical

Dimensions: 17” H x 11” W x 19” D

Weight: 50 lbs.

Mounting: Compact bench top enclosure

Ambient operating temperature range: 0 to 40 degrees C

Relative Humidity: 0 to 90% RH non-condensing

3.3 Description of Controls and Connections

3.3.1 Front Panel

Power Switch

Controls the AC line power to the Model 850C.

Anode and Cathode Supply Lines

These heated hoses supply the reactant gases to the fuel cell. We do not recommend

extending these hoses because there will be problems with water condensation. Any spot in the

flow path from the Humidifier tank to the cell that dips below the dew-point value set on the

850C will condense water and create droplets which have a negative impact on cell stability and

performance. Therefore, if making any changes to the flow path, be very aware that your results

can suffer. See Appendix D for details on using the Swagelok® fittings on the ends of these lines.

Sense Lead Connector

Power Switch

Display

Emergency Stop Button

Power Switch

Load Terminals

Temperature Controllers

Anode Supply

Cathode Supply

Cell Thermocouple Connector

Cell Heater Outlet


17

The 850C is engineered for optimum dew point accuracy at 25 degree C ambient

temperature. The minimum achievable dew point is typically 35 degrees C at a 25 degree C

ambient temperature. At higher ambient temperatures, the minimum dew point temperature will

be higher.

Place the included insulating sleeves over the anode and cathode fuel cell fittings after the

cell is attached to minimize condensation of water from the lines at these fittings. This is

particularly important for maintaining optimum low-flow dew point accuracy.

Emergency Stop - Press the RED BUTTON to activate

Pressing this switch purges the cell, removes power to the fuel gas valves in the fuel unit,

initiates a N2 purge, and removes the load current from the fuel cell. If this switch is pressed

while in operation, the FuelCell® software will display an alarm condition on the screen to

notify the user that the fuel supply has been shut off. Turn clockwise 1/8 turn to reset. (Note

arrows). Do not force.

Display

This display is used to display the whole-cell potential, cell current, and alarm messages.

On startup when the AC power is applied, the unit serial number, firmware version, current and

power ratings of the 850C are displayed. These values may be required for troubleshooting or

other service actions.

Temperature Controllers

The anode, cathode, and fuel cell temperature controllers are used to monitor and control

the temperature of anode gas humidifier, cathode gas humidifier, and fuel cell body, respectively.

The set points, read back and alarms are controlled by the FuelCell® program. These three

temperature controllers are programmed at the factory and the user should not alter their internal

settings. DO NOT enter temperature set point values from the front panel of the controllers.

Load Terminals

These are the point of connection of the electronic load to the fuel cell. Note that the

electronic load has a MAXIMUM VOLTAGE rating at its terminals and should not be

subjected to input voltages (applied to the load or sense terminals) in excess of 20 Volts. Damage to the electronics can result, which may require that the model 850C be returned to the

factory for repair. It is very important to use short, low resistance cables for connection to

the fuel cell. Scribner Associates low resistance accessory cables, p/n 890-50-20, should be

used to connect the fuel cell current collectors to the anode and cathode connections on the load

unit. The 850C 100A model may require larger cables. Failure to use adequate cables will

reduce the performance of the model 850C.


18

Note: Cables and connections are particularly critical when using a single cell where

system resistance must be as small as possible to achieve low cell voltages under load. Short

cables minimize stray inductance for best iR and EIS measurement accuracy.

Connection cables should be made as short as practical 12” – 20” (30cm - 50cm) in

length. The SAI accessory cables listed above or finely stranded copper welding cable are

recommended for flexibility. Cable ends should be terminated with solid copper lugs and

securely bolted to the load and the fuel cell current collection plates.

Sense Lead Connector

This connector contains Anode Sense, Cathode Sense, Reference Sense, and Reference

Return signals. The Anode Sense lead MUST be connected directly to the anode plate of the fuel

cell. This lead provides a reference point for all fuel cell potential measurements. The

Reference Sense lead may be connected to an internal reference electrode if desired. Anode half-

cell, compensated anode potential, and anode iR drop potential are measured by this connection.

If no reference electrode is used it is suggested that this connection be connected to the Anode

Sense lead. The Cathode Sense lead should be connected directly to the cathode plate of the fuel

cell. This lead provides for the compensated whole cell potential and whole cell iR. The

Reference Return signal is the negative side of the Reference Sense Measurement. The

Reference Return signal should be connected to the Anode Sense lead unless a differential

measurement such as a stack middle cell or two electrode measurement is made.

Cell Thermocouple Connector and Heater Outlet

The Cell Heater Outlet provides 120VAC at up to 200W for connection of the fuel cell

heater. The cell heater used should have a grounded outer sheath or a double insulation system

that is checked periodically to prevent damage to the test system and operator hazards. A

thermocouple input and a temperature controller are provided to regulate and control the

temperature in the cell under test. Depending on the type of unit ordered, either the standard

type "T" (blue) or optional type “K” (yellow) thermocouple with mating connector is required,

and miniature OMEGA brand (yellow type “K” or blue type “T”) male connectors may used.

The Cell thermocouple should be installed into the fitting on top of the cell and connected to the

thermocouple jack on the front of the 850C.


19

3.3.2 Rear Panel

AC Power Input

The model 850C is supplied with a standard IEC power input socket and filter for

connection to 100-120 Volts AC, 50-60 Hz. A 3AG size time delay fuse should be in the AC line

fuse holder which is part of the input socket. The fuse rating is 8A or 10A depending on the rear

panel marking. To replace the fuse, carefully open the holder and remove the red insert. Before

replacing, determine the reason for failure of the fuse, such as a shorted fuel cell heater. Reinstall

in the same position with a new fuse after the problem has been corrected.

IEEE-488 / GPIB Connector

This is for the connection of the Model 850C to a compatible PC for control and data

acquisition by the FuelCell®

software. Either a NI PCI-GPIB board or USB-GPIB adaptor cable

may be used.

Cooling Air Intake and Exhaust

All exhaust air for the model 850C exits through the back of the case. Allow at least 12

inches of clearance behind the rear of the unit to ensure unrestricted air flow. Cooling air is taken

in under the case and from the rear of the case. DO NOT obstruct air flow around the lower

edges of the case. Do not place this instrument in a fume hood and avoid corrosive atmospheres.

Anode, Cathode, Purge and Optional Gas Inlets

Swagelok® connectors are provided for incoming dry gasses regulated @ 45psi – 60psi.

The anode supply gas is usually hydrogen, the cathode gas is usually oxygen or air, and the

purge gas may be nitrogen or argon. If the system will be used with a direct methanol fuel cell

or other type that doesn’t require anode gas, then the anode gas does not need to be connected.

See the FuelCell software manual for details on disabling the Anode Pressure alarm in this case.

AC Power Input

Cooling Fan Exhaust

IEEE-488/GPIB Connector

Anode Fuel Supply Fitting

Cathode Oxidant Supply Fitting

Optional

Nitrogen Purge fitting

Auxiliary Signals Connector

Humidifier Water Fill Valve

DI Water Inlet fitting


20

The Optional gas inlet (if present) is used to mix the output of one or more external mass flow

controllers into the anode or cathode gas stream, depending on the build option of the 850C. See

Appendix D for details on using Swagelok® fittings

Water Inlet Fitting

Scribner Associates recommends using high-purity water (ASTM Type I, 18 M-cm

minimum resistivity) in the 850C humidifiers. The water supply must be connected to the

Swagelok fitting on the rear of the 850C. Inert, ¼” OD plastic tubing is recommended, such as

TEF or polypropylene, with nylon ferrules. The high-purity water supply should have a moderate

pressure of less than 65 PSIG static. For models without the auto water fill (AWF) option, a

gravity-feed tank may be used for water supply provided the head (pressure) is greater than that

of any back-pressure applied to the cell. For models with the AWF option, the water pressure

must be between 30 and 65 PSIG static. If the fuel cell is being operated under backpressure, the

water pressure must be at least 30 PSIG greater than the applied backpressure value but must still

be no more than 65 PSIG static. For example, if 20 PSI back pressure is used, then the supply

pressure must be between 50 and 65 PSI. If the water supply has pressures above 65 PSIG, a

water pressure regulator must be used. See Appendix D for details on using Swagelok® fittings

Humidifier Water Fill and Drain

For models without the AWF option, the Humidifier Water Fill Valve should always be

in the OFF position (up) except when water is being added to or removed from one of the

humidifier tanks. When adding water to one of the tanks, observe the tank sight glass through the

850C enclosure window on the left side. The time required to fill or add water to the tanks will

vary depending on the water pressure being supplied. Fill only to the red line on the top of the

sight glass. DO NOT overfill the tanks, or water may flow directly into the fuel cell.

For models with the AWF option, the Humidifier Drain valve must be closed unless the

tanks are being drained. The water supply should always be present at the above pressure

specification since the automatic water fill can be initiated at any time power is applied.

To drain the tanks, turn off the unit, disconnect the heated lines from the fuel cell, and

connect a hose from the Drain fitting to a bucket or sink (fill fitting for units without AWF

option). Turn the valve to the Anode or Cathode position to drain the respective tank and turn it

to Off when water stops flowing.

Auxiliary Signals Connector

The Auxiliary Signals Connector allows external reformate mixing, data acquisition, and

other optional equipment to be connected to the 850C. Do not connect anything other than

accessories approved by Scribner Associates, Inc. to this connector. See Appendix B for

information on connecting devices to this connector.

3.4 GPIB Board

It is necessary to properly install the USB to GPIB cable before using FuelCell®. PCs

provided by Scribner Associates normally have the National Instruments NI488.2 GPIB drivers

and the FuelCell® software already installed. The USB to GPIB cable, as furnished by National


21

Instruments, comes with a software CD containing the GPIB drivers, which must be installed

before the FuelCell® software will run. The National Instruments PCI-GPIB card may be used

instead of the USB to GPIB cable. In either case, install the GPIB drivers before connecting the

card or cable.

Important Notes:

1) National Instruments sells a wide range of GPIB boards (GPIB-USB-B, PCI-

GPIB, PCMCIA-GPIB, etc.). FuelCell is compatible with the current version of each of the

NI boards. If you have a very old version of one of these boards, it may not be compatible.

The board in question must have 32 bit drivers available. Note that only GPIB-USB-B,

PCI-GPIB and PCMCIA-GPIB are compatible with Windows XP Pro/Vista/7/8. Our

recommended solution is the National Instruments GPIB-USB-B adapter.

2) Always use an up-to-date driver when installing a GPIB board or adapter.

National Instruments distributes updated GPIB drivers through its Web site:

http://www.natinst.com phone number: (512) 683-0100 (USA).

3) Carefully follow the instructions provided with the National Instruments GPIB

board/adapter. Note that some boards such as the PCI-GPIB and the GPIB-USB-B require

that the GPIB driver software be installed before the board is installed.

3.4.1 Electrical Connections

The 850C requires AC power, 120V 50-60Hz, at up to 960 or 1200 Watts, depending on

the rear panel marking, with all heaters running. If this voltage is not available, a step-down

transformer is required with a grounded North American type outlet and a power rating of at

least 960 watts if the rear panel marking of the unit indicates an 8 amp fuse and 1200 watts if the

rear panel indicates a 10 amp fuse. It is recommended that a UPS device be used to avoid test

interruption in the event of a power glitch. Contact the factory for more information.

3.4.2 GPIB Connections

A GPIB type cable is necessary to interconnect the computer and the 850C fuel cell test

system. The figure below illustrates the communications connection. Connect the 850C Fuel

Cell Test System to the computer with a USB to GPIB Adaptor cable (GPIB-USB-B). Secure the

cable connector with the built in screws. Do NOT over tighten the screws.

The GPIB address is factory set to 7 and should not need to be changed by the end user.

To change the GPIB address, please refer to the instructions in Item #5 in Appendix B.


22

3.5 Fuel Cell Test Fixture

The 850C FCTS electrical connections consist of a set of heavy gauge cables, to carry the

cell current and sense lead connections to measure voltage at the cell itself. Sense leads must be

attached directly to the cell terminals for accurate measurement. The electrical connections

between the load and the fuel cell under test depend on the type, size and configuration of the

fuel cell being used. All fuel cells have at least two electrical connections: the anode (negative)

and the cathode (positive).

The Model 850C is furnished with a sense lead assembly which attaches to the connector

provided on the front of the unit. Each lead is furnished with a banana plug which may be

replaced with termination suitable for the cell. The sense lead connections are provided to

accurately measure the cell voltages at the cell terminals or current collectors. It is very

important that these leads be used and connected properly. The cell voltage and internal

resistance measurements will be performed between the sense leads, so their placement on the

cell end plates will affect the actual readings.

A pair of cell cables consisting of a large current carrying conductor for each electrode is

required for fuel cell operation.

The sense leads are color-coded as follows: (see Sense Lead drawings below)

Red Cathode (whole cell +) sense

Black Anode (whole cell -) sense

White Reference (half cell +) sense

Green Reference (half cell -) return

PC

850C FCTS

GPIB-USB-B

Cable


23

Two terminal Cells:

Connect the anode and cathode fuel cell leads to the large lug terminals on the load unit.

Connect the sense leads from the 850C Sense Connector to the respective cell electrodes. If a

reference electrode is to be used, connect it to the Reference Sense lead. Connect the Reference

Return lead to the anode side of the stack. The Reference Sense and Reference Return leads

allow any voltage up to 9.999 Volts to be measured differentially. This includes an intermediate

cell of a stack or the Reference Electrode of an intermediate cell. The common-mode voltage on

this pair of leads may be up to +/- 10 Volts. If you wish to connect the load to a two terminal

cell (a cell without a reference electrode), connect the Reference Sense and Reference Return

leads to the anode side of the cell.

Three terminal Cells:

Some fuel cell configurations use three electrodes if a reference electrode has been built

into the cell. Connect the anode and cathode fuel cell leads to the large lug terminals on the load

unit. Connect the sense leads from the 850C Sense Connector to the respective cell electrodes. If

a reference electrode is to be used, connect it to the Reference Sense lead. Connect the Reference

Return lead to the anode side of the cell. The Reference Sense and Reference Return leads allow

any voltage up to 9.999 Volts to be measured differentially. This includes an intermediate cell of

a stack or the Reference Electrode of an intermediate cell. The common-mode voltage on this

pair of leads may be up to +/- 10 Volts.

Black

Green

Red

White

3 Term Cell


24

Stacks or other 4-terminal cells:

Some fuel cell configurations consist of a "stack" of two or more cells connected

electrically in series. In this case, the outermost anode and cathode connections would be used,

for the Anode Sense and Cathode Sense leads. The Reference Sense and Reference Return leads

may be used to measure the voltage of one or more intermediate cells of a sack.

CAUTION: The electronic load has a MAXIMUM VOLTAGE rating at its terminals and

should not be subjected to input voltages (applied to the load or sense

terminals) in excess of 20 Volts. Damage not covered by warranty may result

to the load.

Black

Green

Red

White

Stack or other 4-terminal cell (Measurement of intermediate cell of stack)

Chapter 4 System Components and Configuration

25

CHAPTER 4

SYSTEM COMPONENTS AND CONFIGURATION

4.1 Basic System Components and their Descriptions

A basic setup to test a PEM type fuel cell requires the following items:

1. A supply of reactant gasses with humidification and flow control

2. A method of extracting and measuring electrical power from the fuel cell

3. A data acquisition system to capture all fuel cell operating parameters

4. System software for controlling the test system and all of its components

4.1.1 Fuel Source, mass flow control and humidification

A source of fuel (typically H2 or some mix containing H2) and oxidant (O2 or air, which

will also be called a fuel component) must be provided to the fuel cell. A means must be

provided for starting and stopping the flow of fuel to the cell such as electrically controlled

valves. These valves can be under the control of various safety circuits that help warn the user of

fuel pressure or electrical power loss and provide some protection for the system by closing off

the fuel supply and optionally opening an inert purge gas supply (such as N2) automatically to

remove the combustible reactants. A way of controlling the fuel flow rate may be desired such

as a mass flow controller on one or both of the fuel paths. Some designs of PEM fuel cells may

require humidification of one or both of the fuel streams. For this application, humidifier tanks

with temperature controllers are required for the reactant gas flow paths. Depending on the

size of the fuel cell to be tested, a method of heating the cell to the required operating

temperature may be required. Larger fuel cells may produce enough internal heat to be self-

heating. All of these functions are provided by the model 850C.

4.1.2 Electronic Load

A method of extracting and dissipating electrical power from the fuel cell under test is

needed. Typically this is a resistive device that will cause current to flow when connected to the

terminals of the fuel cell. In this case an electronic load will be used. The electronic load

consists of a bank of semiconductor devices capable of conducting large amounts of current,

equal to or greater than the fuel cell output, and dissipating this current as heat to ambient air or

cooling water. The electronic load must have maximum current (Amperes), potential (Volts) and

power (Watts) ratings adequate for the fuel cell to be tested.

In addition to the above mentioned characteristics, the load must be able to achieve

sufficiently low internal resistance to cause the maximum desired current to flow from the fuel

cell at the lowest desired cell potential. This specification is minimum resistance, or maximum

current at a given cell potential. The total cell current will be limited, therefore, by the minimum

resistance of the load plus the resistance of the cables and connections between the load and the

fuel cell. It is important to use the largest (and shortest) practical conductors between the fuel

cell and the load for optimum performance. All of these functions are provided by the model

850C.


26

4.1.3 Data Acquisition

A data acquisition system is needed to measure all of the desired operating parameters

of the fuel cell under test and present this data in graphic and numerical form for the user. The

use of a PC permits the fuel cell parameters to be monitored, controlled, and stored for later

analysis.

Typical operating parameters that may be measured are cell potential, half cell

potential (if an internal reference electrode is available), iR corrected potentials, cell current, cell

power, fuel component mass flow rates, cell temperature, fuel component temperature, dew

points and related safety conditions.

4.1.4 System Software

The FuelCell® test system software for controlling the test system and all of its

components is required for the PC as well as an interface to the various parts of the test system.

This will provide the focal point for experiment definition and setup, experiment control, fuel

cell monitoring for safe operation, data logging, data display and graphing test results.

The operating software should have provisions for controlling all of the operating

conditions of the fuel cell, menus to input the characteristic parameters for the cell, (e.g.

electrode area), operating temperature and required fuel mass flow rates, etc. Provisions should

be made for safety shutdown of the fuel cell and test termination if maximum and/or minimum

cell ratings are exceeded, such as maximum current, power or temperature, minimum cell

potential, loss of fuel supply or electrical power, etc.

4.2 Fuel Source System Configuration

The 850C is designed to eliminate typical gas handling system problems. Specially

designed, 100% efficient humidifiers and fuel transport hoses allow the 850C to produce steady,

reliable saturated reactant gasses at a variety of flows, temperatures and dew points. Solenoid

and check valves offer enhanced safety by enabling automatic shutdown/purge and eliminating

gas back-flow problems. Separate paths for reactant gasses help prevent system contamination,

and increases volatile fuel safety.

4.2.1 Humidified Reactants, Hydrogen and Oxygen and/or Air

A fuel cell requires external humidification and is designed to use hydrogen on the anode

side of the MEA and oxygen and/or air on the cathode side. External humidification usually

involves sparging each reactant gas through a heated tank of high-purity water (ASTM Type I,

18 M-cm) achieve reactant gas dew points that equal the humidifier set point temperature

requires careful design and manufacture of all of the system components. The dew point

temperature is typically selected to ensure saturation (100% relative humidity) of the reactants

when they reach the MEA. A research type of cell is usually operated as a flow through cell to

achieve uniform distribution of reactant gasses, expel excess water, and with optional back

pressure, maintain desired operating pressure.


27

Fuel cell operating characteristics:

Atmospheric or pressurized operation of anode and cathode - MEA operates with

balanced or at a low differential pressure.

Requires external humidification of the fuel reactants prior to introducing them into

the fuel cell.

Typically operated as a flow through cell with optional back pressure control to

elevate internal pressure.

Excess anode and cathode humidification condensate and generated water are

removed by expulsion or through back pressure regulators.


28

850C Flow Diagram with Multi-Gas and Backpressure Option

N2

1

2

C a t h o d e

A n o d e

T

H T

MFC

2

PS

BP

BP

Vent Vent

MFC

PS

PS

H

T

1

3

FUEL

3

OXIDANT

Fuel Cell

T Thermocouple

Back Pressure Regulator

Pressure Gauge

PS

Heater

BP

H Humidifier

MFC Mass Flow Controller

Pressure Switch

3-Way Valve

Solenoid Valve

Check Valve

LEGEND

PURGE

Multi-Gas Option Multi-Gas Option

Chapter 5 Getting Started and Operation

29

CHAPTER 5

GETTING STARTED AND OPERATION

Chapter 5 deals with initial start up of the 850C fuel cell test system and the FuelCell® software.

This includes application of the fuel cell gasses, electrical and mechanical connections to the fuel

cell test fixture (cell electrodes or current collectors, fuel gas feed and vent lines), applying AC

power to the test system hardware and starting the FuelCell program to control the test system

and collect data.

5.1 Preparation of Fuel, Gas and Electrical Connections

Locate the system test equipment – the 850C Fuel Cell Test System and the PC used to

control and monitor the fuel cell tests, in a suitable lab environment. The user is responsible for

determining and implementing all safety requirements. Refer to the READ ME FIRST - 850C

Installation Procedure document in this manual and attached to the 850C. Refer to the supplied

manuals to connect the gas and high-purity water (ASTM Type I, 18 M-cm) supplies, AC

power and GPIB communications cable to the equipment. See Appendix D for details on using

Swagelok® fittings.

When the user has connected the appropriate fuel and purge gas sources to the test system

gas inputs, ALL fuel gas regulators, fittings, connections, gas tubing, and valves should be leak

tested for safety. Provide for adequate ventilation. DO NOT place or operate the model 850C in a

fume hood.

The 850C must pass a comprehensive leak down check before it leaves the factory.

The installer is responsible for checking all user connected fittings, hoses, tubing and other

connections.

Observe all safety precautions associated with the fuels in use. When in doubt,

consult the gas supplier's Material Safety Data sheets.

The 850C fuel cell test system gas hardware is designed so that the purge gas valves are

normally open at all times when fuel gas is not applied, unless there is a complete AC power

failure, in which case, all gas flows will cease. As a result, if electrical power to the system is

interrupted, the fuel cell purge gas will not flow, but the reactant gasses will be turned off. For

this reason, a UPS is recommended for all installations.

At this time, the purge gas tank valve (normally N2) and its regulator should be opened to

verify that the purge flow is present. Pressure switches are installed on the incoming gas lines to

verify that adequate supply pressures of gasses are present for operation of the test system. If any

of the three pressures fall below 45psi, the reactant gas flow and load will not activate. This is a

safety feature.

Chapter 5 Getting Started and Operation

30

5.2 Check List Before Proceeding:

1) Inspect all fuel gas connections

2) Leak check all fuel gas connections

3) Examine all cable connections between the test equipment and the fuel cell

4) Install the NI software drivers

5) Install the GPIB board in the PC

6) Perform the GPIB hardware tests on the National Instruments board

Turn on the computer. It is assumed that the computer has been properly configured with the

GPIB-USB interface cable, the National Instruments GPIB drivers, and the FuelCell® software

installed as outlined previously. DO NOT start the FuelCell software at this time.

5.3 Apply AC Power

Connect the 850C power cord to a power outlet. If the available line voltage is not 120

volts, 50-60Hz, see Section 3.4.1 on using a step-down transformer. Apply AC line power to the

Model 850C by placing the POWER switch in the ON position. The cooling fan in the 850C

should start and the front panel display and temperature controllers should illuminate. The

temperature controllers should display "SELF TEST" for several seconds and then revert to their

default set points. The default set point is 15 °C for all three temperature controllers. A note

about the temperature controllers: DO NOT use the front panel controls on the temperature

controllers to adjust the temperature set points! The set point values should ALWAYS be

entered from the FuelCell® software menus. If the controllers display other than 15 °C set point

(green display) when 850C power is applied (before starting the FuelCell® software), reset them

to 15 °C.

The main display on the right side of the front panel should read a startup message for a

few seconds after which it should display voltage and current. If the GPIB address of the 850C

needs to be changed or reset, see Appendix B.

5.3 Storage and Shipping

Do not ship, store, or position 850C on its side or other than normal upright with

water in the humidifier tanks.

Remove water from both humidifiers as described in Section 3.3.2 before shipping or

preparing for long term storage. Cap all input and outlet fittings before storage.

Chapter 6 850C Detailed Specifications

31

CHAPTER 6

850C DETAILED SPECIFICATIONS

The model 850C Compact Fuel Cell Test System is designed to meet all small to medium fuel

cell research and development needs. A low resistance semiconductor-based test load and

internal data acquisition and control electronics, dual high efficiency humidifiers and mass flow

controllers, coupled with our FuelCell® software package, allow precise computer control and

monitoring of all fuel cell operating parameters.

6.1 General Features

Electronics:

Remote operation from IEEE488 (GPIB) interface.

2 line front panel text display.

Constant current mode.

Constant voltage mode.

Constant power mode.

Integral current interrupt cell (iR drop) cell resistance measurement.

Optional model 880 FRA (impedance analyzer) for HFR and EIS measurement.

Automatic shutdown in hardware and software for overcurrent, undervoltage, overpower,

load temperature, humidifier and cell temperature conditions.

High impedance whole cell and reference electrode (half cell) sense inputs.

Cell main terminals and sense inputs tolerant of non-isolated cell.

Fuel Handling:

Internal temperature controllers for cell heater and two reactant humidifiers.

Purge and reactant gas solenoid valves.

Reactant (fuel and oxidant) and purge gas supply pressure sensors.

Efficient dew point humidifiers with insulated, heated cell lines.

Manual water fill of humidifiers.

Optional auto water fill of humidifiers.

Low water level sensors for humidifier tanks.

Mass flow controllers in purge and reactant gas path.

System check valves for gas, liquid safety.

6.2 Model 850C Hardware Specifications

Electronic Load:

Maximum Load Current: 5, 15, 25, 50, or 100A

(configuration dependent)

Maximum Load Power: 50W (100W for 100A model)


32

Minimum Load Resistance: < 2mOhms (100mV @ 50A at load

terminals) for 100A or 50A model

Current Resolution: 1mA on 5 and 15A models,10mA

for 25A, 50A, and 100A models

Current Accuracy: 0.3% of full scale current rating.

Voltage Measurement and Data Acquisition:

Maximum Whole Cell Voltage: 20V

Maximum Reference Electrode Voltage: 9.999V

Sense Lead Input Resistance: > 35k ohms

Voltage Resolution: 1 mV

Voltage Accuracy: +/-3mV +/-0.3% of reading

Voltage and Current Data Update Rate: 100Hz

Reactant Gas Control System:

All 316 SS construction of humidifiers, flow path, valves and mass flow

controllers, with Swagelok® fittings and heated reactant delivery lines.

Mass Flow Control: Standard Anode 1000 sccm and cathode

2000 sccm Software controlled mass flow

controllers. Automatically controlled N2

purge valves on anode and cathode.

Alarm Inputs: Gas supply pressures (3), humidifier water

levels (2) and external (1).

Backpressure Control: Optional, 0-30 PSIG, requires 850BP

accessory.

Temperature Controllers:

Quantity: Three; cell fixture; anode and cathode

humidifiers

Set and Report Accuracy: ±0.25% of span, ±1 least significant digit

Sensor Type: Thermocouple, Type T for cell (K optional)

Humidifiers:

Type: Dual bottle-type, all 316L SS, 270 watt

heater per bottle (360W for >2SLM units)

Automatic water fill optional.

Temperature Range: Ambient to 99 degrees C.

Environment:

Operating Temperature: 0-40 degrees C

Power Source: 120V 50/60 Hz 8A or 10A max

Enclosure Type: Single benchtop enclosure

Size: 17” H x 11” W x 19” D (+ 11” for heated

gas lines) 44 x 28 x 49 (+ 28cm); 50 lbs.

Safety Features: Automatic shutdown and N2 purge with under voltage,


33

over-current, over-temperature, loss of supply pressures, low water, communications

failure or external alarm. Manual Emergency Stop switch for manual shutdown by

operator.

See the FuelCell for Windows - Fuel Cell Test Software Manual for further details pertaining to

the FuelCell Software.


34

Appendix A Troubleshooting

35

APPENDIX A

TROUBLESHOOTING

Notes: Problems with the board or communication are typically the result of incomplete or

improper configuration of the National Instruments NI488.2 GPIB interface driver software. The

National Instruments PCMCIA-GPIB, or PCI-GPIB interface boards may be used, however the

newer GPIB-USB-B is the recommended interface. Note that the PC-II interface is not

WinNT/2000/XP compatible. Note that version 3.x and later of the FuelCell software is available

as a 32 bit program only and is not compatible with Windows 3.x. Recommended operating

systems are Windows XP Pro/Vista/7/8. Operation from Windows 95/98/ME/XP Home is not

recommended.

Communication Problems

See FuelCell Software Manual for more information.

“Error locating GPIB drivers. Press OK to exit.” This error will appear immediately after

starting the program if the file GPIB.DLL cannot be found. The solution to this problem is

making sure that the GPIB Interface Driver software is properly installed.

“GPIB Communications error” This error will appear immediately after starting the program if

the GPIB address of the model 850C does not match the settings in the fuelcell.ini file, OR if the

power to the instrument is off. The SAI 890 - OLE window will display ‘Connect Failed’ and

‘Board 0, Address X’ where X is the address of the instrument. Make sure that the model 850C

power switch is in the ON position and verify that the GPIB address is set correctly. Each

instrument connected to the GPIB bus must have a unique address. Use NOTEPAD to view the

fuelcell.ini file (located in the \fuelcell directory) and make sure that the GPIB address listed

there is configured as board 0 and the correct address. The factory default GPIB address for the

model 850C is set to 7 and should be used unless a change is required. See Appendix B if the

GPIB address needs to be changed.

“FuelCell: Serial Poll Error” Communications with the instrument has been interrupted. This

can occur with a momentary power outage. The SAI890OLE program will try to reestablish

communications after 30 seconds. If the problem persists, cut and paste the text of the errors and

email to [email protected].

“Temperatures read -999” Communications with the temperature controllers have been lost.

Allow at least 10 seconds after power up of the model 850C before starting the FuelCell program

to allow the temperature controllers to initialize. Display of this message can indicate the failure

of one of the temperature controllers. Contact the factory for assistance.

Appendix A Troubleshooting

36

Hardware Problems

1) No power when unit is turned ON, displays do not light. AC power is not available

to model 850C.

Fuse on rear panel of the control unit may be blown. Replace with 8 Ampere, time delay

3AG size time delay type fuse. Determine cause of failure before proceeding.

2) Alarms when FUEL ON button is pressed in software.

Emergency Stop switch activated, or Inadequate purge and/or fuel gas pressure causing

shutdown. Check error messages, humidifier water levels and supply gas pressures. For

units with the auto water fill (AWF) option, a low water alarm indicates that the

automatic water fill system tried unsuccessfully to fill the indicated humidifier. Ensure

that the high-purity water supply is connected and pressure is between 30-65 PSIG static.

After correcting the water supply, close the software and turn the power off and on to

reset the AWF system. It should start filling the previously indicated humidifier, which

can be verified from the window in the side of the enclosure.

3) Incorrect or extremely noisy reported cell voltage.

Sense leads not connected or reversed. The sense leads are required to measure the fuel

cell voltage and should be connected at the cell independent of the load current carrying

leads. These will measure the actual value at the cell plates. The instrument will not

operate if these are not connected correctly. Connect the Reference Sense and Reference

Return inputs to the Anode Sense lead if not used. See Section 3.5 for more information.

Note: Observe the maximum common mode voltages marked on the front panel. A

small amount of common mode voltage can be rejected by the measurement circuitry, not

to exceed a value of 10 Volts peak. Do not exceed any of these ratings or damage to the

model 850C may result.

4) Over temperature shut down.

Check cooling restrictions. Prolonged over temperature operation may damage the load

electronics.

Appendix B Using the Auxiliary Signals Connector

37

APPENDIX B

USING THE AUXILIARY SIGNALS CONNECTOR

This connector is provided for connecting accessories approved by Scribner Associates, Inc to

the Model 850C. The connector is of the female 25-pin DSUB type. A mating male 25-pin

DSUB connector should be used for the 850C auxiliary signals. The signals are shown in Table

B1 followed by a description.

Pin # Signal Description Pin # Signal Description

1 External Alarm Input 14 Display Select / GPIB Address Set

2 Digital Signal Ground (Alarm Return) 15 RS485 ‘B’ Line

3 RS485 ‘A’ Line 16 Anode and Cathode Burp Return

4 Cell Heater Control (+5V) 17 Power On Signal (+5V)

5 Cell Heater Control Return 18 Cathode Burp

6 Anode Burp 19 Analog Signal Ground

7 Analog Signal Ground 20 Do not connect

8 Do not connect 21 Do not connect

9 Reformate #3 MFC Control (0-5V) 22 Analog Signal Ground (MFC return)

10 Reformate #3 MFC Readback (0-5V) 23 Reformate #2 MFC Control (0-5V)

11 Analog Signal Ground (MFC return) 24 Reformate #2 MFC Readback (0-5V)

12 Reformate #1 MFC Readback (0-5V) 25 Analog Signal Ground (MFC return)

13 Reformate #1 MFC Control (0-5V)

Table B1 – Auxiliary Signals

1. External (Auxiliary) Alarms – This contact closure input is used with a mechanical

sensor or switch that detects an alarm condition, with the other side of the switch

connected to one of the Digital Signal Ground pins.

2. Mass Flow Controller (MFC) Control and Readback Signals – These connections are

for an MKS Model 1179A or equivalent controller using an analog 0-5 volt control

signal. Other MFCs with a 0-5 volt control input may be used provided the control

and readback signals share a common return (signal ground) connection. Check this

with the MFC manufacturer. A cable assembly must be constructed to provide the

Control, Readback, and one of the Analog Signal Ground signals to the connector on

the mass flow controller. A +15/-15 volt power supply must be provided by the user

with sufficient current capability for the sum of power draws of the anode, cathode,

and reformate (if used) MFCs. A second power supply may be used to power the

reformate MFCs. These signals may also be used to control a variable-speed pump

for DMFC or similar testing. Consult the factory for more details.


38

3. Cell Heater Control and Control Return – This signal may be used to operate the cell

heater using an external solid-state relay (SSR) with ratings and heatsinking

appropriate for the voltage and current ratings of the heaters. The control signal is 5

volts DC at up to 10mA and must be taken between these two pins. Normally-closed

mechanical thermostats (limit switches) which open at a high temperature should be

wired in series with each heater and in good thermal contact with the cell or furnace

being controlled with that heater. The opening temperature of the thermostats should

be a safe value but above the normal operating range. This is intended for a large cell

heater or SOFC (solid oxide fuel cell) furnace which exceeds the 2 amp current

output capability of the front panel heater receptacle or requires a voltage other than

the 100-120 volt 850C power.

4. RS485 Interface – Certain temperature controllers, data acquisition modules, and

other RS485 devices are supported by the FuelCell™ software. Consult the factory

for a list of supported devices. All RS485 devices should be connected in-line (daisy

chain, not star) on a single shielded twisted-pair cable. At the last device, connect a

120 ohm, ¼ watt resistor across the lines. Devices with a signal ground connection

(non-isolated interface) should have this attached to the cable shield through a 100-

150 ohm resistor. The shield should also be connected to one of the Digital Signal

Ground pins through a 100-150 ohm resistor. Do not connect anything else to the

RS485 signals. Refer to the TIA/EIA-485 specification for further details.

5. Display Select / GPIB Address Set – This signal, when momentarily tied to one of the

Digital Signal Ground pins, performs one of two functions. If the 850C power is

turned on, the front panel LCD display toggles between Whole Cell and Half Cell

voltage each time the connection is closed. If the connection is made and held and

the E-Stop button is not pushed in while the 850C power is turned off and the power

is then turned on, the 850C goes into the GPIB Address Set mode. The LCD display

prompts the user to release and press the button (disconnect and connect the signal).

This causes the GPIB address on the LCD display to increment. This is repeated until

the desired GPIB address appears, after which the E-Stop button is pressed to store

the address and enter normal 850C operating mode. Note that operation with a

different GPIB address requires that the “fuelcell.ini” file be modified to use that

address. It is normally not necessary to change the GPIB address from the factory

default value of 7.

6. Power-On Signal – This signal provides 5 volts through a 470 ohm resistor as an

indication of 850C power on. An LED or SSR input can be connected between this

signal and one of the Digital Signal Ground pins.

7. Burp valves – If used, burp solenoid valves should be used with SSRs having

appropriate ratings for the valves. The control signal is 5 volts DC at up to 10mA.

See Figure B2 for typical connections of these components. Note that mass flow

controller (MFC) pin assignments shown are for MKS 1179A or M100B type MFCs.

Consult the MFC user’s manual for wiring of other brands or models. All line voltage


39

wiring must comply with regulatory requirements and electrical codes and use general

safe wiring practices. Keep all line voltage wiring separate from the 850C Auxiliary

signals.

4

5 T’stat Cell Heater

Cell Heater and Solid-State Relay (SSR)

+

In

-

Out

SSR

RS485 ‘A’

2

3

RS485 ‘B’ 15

A

GN

D B

120

ohm

1/4W

Temperature Controllers or Other

Compatible RS485 Devices

1 Aux Alarm

A

GN

D

B

A

GND

B

Cable Shield

8

12

2

Reform 1

Mass Flow

Controller

7

5

6

8

12

2

Reform 2

Mass Flow

Controller

7

5

6

8

12

2

Reform 3

Mass Flow

Controller

7

5

6

13

12

25

Reform1 MFC Ctrl

MFC Signal Ground

-15V Com

+15V

Power Supply

24

Reform2 MFC Ctrl

Reform2 MFC Read

10

Reform3 MFC Ctrl

Reform3 MFC Read

MFC Signal Ground

Reform1 MFC Read

22

23

9

120

ohm

1/4W

Digital Signal

Ground Alarm

Sensor

Cell Heater Control +

Cell Heater Control -

11

MFC Signal Ground

16

14 Display Select /

GPIB

Digital Signal

Ground Pushbutton

or Jumper

AC Line In

MKS1179A MFC

Wiring Shown

17 Power-On Signal

-

In

+

Out

SSR


40

Figure B2 – Typical Auxiliary Signal Wiring

-

In

+

Out

SSR

Anode Burp

Valve(Note 7)

-

In

+

Out

SSR

CathodeBurp

Valve(Note7)

AC Power

L N

Anode Burp Ctrl

Cathode Burp Ctrl

Burp Control Com 16

6

18

Appendix C Using A Peristaltic Pump For Testing of Liquid Fueled Fuel Cells

41

APPENDIX C

USING A PERISTALTIC PUMP FOR TESTING OF

LIQUID FUELED FUEL CELLS

The Model 850C supports the use of a Gilson Minipuls 3 peristaltic pump for supplying

anode liquid fuel to a DMFC or similar type of fuel cell. Before using this pump, the system

needs to be configured and the user needs to understand issues involved with the use of this

pump.

These instructions assume that the user has successfully installed the 850C and FuelCell

software and configured the unit for normal operation with a PEM fuel cell using anode and

cathode gases.

Setup of Pump

The Minipuls 3 pump operates at a maximum pump head speed of 48 RPM. The

resulting maximum flow rate is determined by the type of tubing used and the pump head that

the pump is equipped with. Consult the Minipuls3 manual for information for flow rates with

various pump head, pump speed, and tubing type combinations.

Determination of Flow Rate

After selecting a pump head and tubing, determine the flow rate when the pump is

running at maximum speed (48 RPM). This can be done by filling a graduated cylinder from a

water container and timing with a stopwatch or by connecting a commercial precision flow meter

to the pump. Note that any back pressure on the pump outlet presented by the fuel cell may

affect the flow rate, so the flow should be measured under conditions as close to the actual cell

setup as possible.

Configuring FuelCell software

Make a copy of the file “fuelcell.ini” in the FuelCell working folder (usually

“C:\fuelcell”). Name this copy “PEM fuelcell.ini”. This file will contain the previous 850C

configuration when used with anode and cathode gases and can be used to restore the test

system to this configuration later. Start the FuelCell software. Enter the “File>Instrument

Configuration” menu and specify the 850C’s serial number when prompted. In the “Fuel

Configuration” tab, select “Liquid Pump” for Anode Fuel Flow Control Type. For “Full

Flow of Controller”, enter the flow rate (in liters per minute) from the previous step. See

Figure P1. Set the Offset Control Signal and Minimum Control Signal values to zero. Set

“Controller Channel” to “Reform #1”. Click on the Alarms tab and uncheck the box Use

Anode Gas Pressure Sensor. If no gas flow is desired on the cathode side of the cell when

fuel is not applied in the software, uncheck the box Use Purge Gas Pressure Sensor. If

cathode air or purge gas is desired when fuel is not applied in the software, leave the Purge

box checked and see the next section below. Click OK and select the option to save the

settings. Close and restart the FuelCell software.


42

Cell Cathode Purge Configuration

If it is desired to purge the cathode when fuel is not applied in the software, leave the

Purge box from the previous section checked and connect purge gas (usually nitrogen) to the

850C’s Purge fitting. If cathode gas is desired whether or not fuel is enabled, leave the Purge

box checked and connect cathode gas (usually air) to the 850C’s Purge fitting and to the

Cathode fitting. If the Purge box was unchecked, the purge gas supply should be removed

and the Purge fitting capped.

Setting Up the Pump

Turn on the pump’s power switch. Ensure that both ends of the tubing are in a container

of water and press the forward button on the pump. Ensure that the display reads “48.0”,

indicating that the pump is operating at full speed and that the pump head is turning. Press the

Stop button and ensure that the pump stops turning.

Connecting Hardware

Connect the included cable from the 850C Auxiliary Signals connector to the green

connector on the rear panel of the pump.

Figure P1 – Fuel Configuration Menu (22mL/min flow shown)


43

Using FuelCell with the Pump

In the FuelCell software, click the Setup Fuel menu. Set the Anode Minimum Flow

parameter to the flow rate measured with the pump operating at 48 RPM. Set the Anode Load

Based Flow parameters to zero. See Figure P2. If the Enhanced Setup Fuel menu appears, click

Fixed Flow for the Anode side and set it to the measured flow at 48 RPM. Note that depending

on the software configuration, this will be either units of “cc/min” or “L/min”. Click OK. Click

Apply Fuel and verify that the pump runs at full speed (48 RPM). Enter the Setup Fuel menu

and set the Anode Minimum Flow parameter to ½ of the flow rate measured with the pump

operating at 48 RPM. Click OK. Verify that the pump runs at a reduced speed and that the

display on the pump reads between 23.0 and 25.0. Click Stop Fuel and verify that the pump

stops. Change the Setup Fuel menu parameters as needed for the experiment performed. When

finished with the test station after closing the software, turn off the power switch on the rear of

the pump.

Figure P2 – Setup Fuel Menu (Standard menu shown)


44

Appendix D Swagelok® Tube Fitting Instructions

45

APPENDIX D

SWAGELOK® TUBE FITTING INSTRUCTIONS

Appendix D describes use and installation of Swagelok® fittings to attach gas supply lines to the

model 850C. Part D1 describes assembly of standard Swagelok® fittings used to attach the gas

and water supply lines to the rear panel of the 850C. Part D2 describes installation of Swagelok®

PFA fittings on the ends of the heated gas delivery lines on the front of the 850C that attach to

the fuel cell hardware.

Heated Gas Delivery Line Fittings

Current production 850C models use Swagelok® PFA plastic fittings (Figure D2) on the ends of

the heated gas delivery lines. The PFA fittings are better suited for use at the fuel cell-end of the

heated lines and are NOT interchangeable with standard metal fittings. Refer to the Swagelok®

PFA assembly instructions in Part D2.

Note regarding 850C Models with standard Swagelok® Fittings on

the heated supply lines:

Older 850C models used standard metal fittings on the ends of the heated anode and cathode

supply lines on the front of the 850C (see figure). For these 850C models, the fittings are pre-

swaged because the 850C is factory-tested with a fuel cell. For 850C models with metal fittings

on the heated gas supply lines, tighten the fitting slightly with a wrench beyond finger-tight per

the instructions below. Never tighten more than ¼ turn beyond finger-tight or damage to

the heated lines may result.


46

Part D1. Assembly Instructions for Standard Swagelok® Metal Tube

Fittings

Note: These instructions apply to traditional metal fittings and fittings with the advanced

back-ferrule geometry. Refer to the Part D2 below for installation and use of Swagelok®

PFA fittings used on the ends of the heated gas delivery lines.

Figure D1 – Installation of standard Swagelok

® fitting

1. Insert tubing into the Swagelok® tube fitting - Figure D1, left.

2. Make sure that the tubing rests firmly on the shoulder of the tube fitting body and that the

nut is finger-tight.

3. Scribe the nut at the 6 o’clock position – Figure D1, center.

4. While holding fitting body steady, tighten the nut 1-1⁄4 turn to the 9 o’clock position -

Figure D1, right.

Note: For 1/16, 1/8, and 3/16 in. and 2, 3, and 4 mm tube fittings, tighten the nut 3/4 turn

to the 3 o’clock position.

Installation in High-Pressure Applications and High Safety-Factor Systems

1. Follow steps 1 and 2 of the Swagelok® Tube Fitting Instructions above.

2. Tighten the nut until the tubing will not rotate freely by hand.

3. Follow steps 3 and 4 of the Swagelok® Tube Fitting Instructions.

Gageability

On initial installation, the Swagelok® gap inspection gauge assures the installer or inspector that

a fitting has been sufficiently tightened. The inspection gauge is available from Swagelok®.

Position the Swagelok® gap inspection gauge next to the gap between the nut and body.

• If the gauge will not enter the gap, the fitting is sufficiently tightened.


47

• If the gauge will enter the gap, additional tightening is required.

Reassembly Instructions

Swagelok® tube fittings can be disassembled and reassembled many times.

1. Insert tubing with pre-swaged ferrules into the fitting body until the front ferrule seats.

2. Rotate the nut with a wrench to the previously pulled-up position. At this point, a

significant increase in resistance will be encountered.

3. Tighten slightly with a wrench. Note: Do not use the gap inspection gauge with

reassembled fittings.

CAUTION

Do not mix or interchange parts with those of other manufacturers. Swagelok

® tube fittings

are manufactured to exacting tolerances. The critical interaction of precision parts as designed is

essential for reliability and safety. Interchanging and intermixing tube fitting components of

different designs or made by different manufacturers may result in leaks, tube slippage, and may

be dangerous in critical applications.


48

Part D2. Swagelok® PFA Fittings for Heated Gas Delivery Lines

Current production 850C models use Swagelok

® PFA plastic fittings on the ends of the gas

delivery lines on the front of the 850C lines. The Swagelok® PFA plastic fitting, shown in

Figure D2, is better suited for use at the cell end of the gas delivery lines. This fitting is very

durable if used properly, will not damage the heated lines, and may be used repeatedly.

Note that the threads are NOT interchangeable with other Swagelok® fittings.

The Swagelok® part number for the complete fitting assembly is PFA 420-1-2 for ¼” tube-to-

1/8” male pipe threads.

Assembly instructions for Swagelok® PFA fittings as used on heated

lines:

Each current model 850C is furnished with a Swagelok® PFA type fitting for connection to the

fuel cell test fixture.

The blue nut is factory-installed on the end of the anode and cathode heated supply line.

The white male, fuel cell-half of the fitting is supplied with the 850C. The white male portion of

the fitting must be installed by the user on the fuel cell hardware anode and cathode inlet port

before connecting the supply line to the fuel cell. Use Teflon tape on the threads when installing

the male fitting into the fuel cell fixture and do not over tighten.

Figure D2 – Swagelok® PFA 420-1-2 Fitting

To attach the supply line to the fuel cell after installing both male fittings into the fuel cell

fixture, screw both nuts onto the male fittings on the fuel cell until finger tight. With one wrench

on the male portion of the fitting already installed on the fuel cell, tighten the blue nut with a

second wrench until there is no gap between the blue nut and the white male portion of the

fitting. This fitting may be disconnected and connected repeatedly without leakage. Do NOT

use Teflon tape on the threads where the blue nut screws onto the white male fitting.

Photographs ©2006 Swagelok®

Company

Blue nut (female half) factory-installed on heated line

White (male half) installed by user in the fuel cell hardware

Appendix E Multigas Valve Installation Procedure

49

APPENDIX E

MULTIGAS VALVE INSTALLATION PROCEDURE

1. Locate the MultiGas Valve Selector.

2. Facing the rear of the 850C, remove three (3) screws located near the rear panel: top-

right, on the right side-top, on the right-side middle (indicated in the picture below).

3. Line up the holes on the MultiGas Selector with the holes on the 850C.

4. Attach the Anode and Cathode tubes from the MultiGas selector to the Anode and

Cathode gas inlet fittings on the 850C. Attach the Swagelok fittings but do not fully

tighten (see picture below).

5. Using the three (3) screws removed in Step 2, attach the MultiGas Selector to the 850C.

Partially install each screw before tightening all of them (see picture above). Avoid

galling or cross treading when installing the case screws.

Appendix E Multigas Valve Installation Procedure

50

6. Tighten the Swagelok fittings connecting the MultiGas selector to the 850C.

Reactant connections to the Model 850C are made with ¼ in. standard Swagelok®

fittings. For instructions on installing and using Swagelok® fittings see Appendix D;

additional information is available at www.swagelok.com or


7. Continue with installation as described in the 850C Installation Procedure.

8. The picture below shows an 850C with one gas (H2) attached on the Anode side and three

gases (O2, Air and N2) attached to Cathode side of the MultiGas Selector. Note that N2 is

also supplied to the Purge Gas Inlet Fitting.

http://www.swagelok.com/


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