process duct heaters - custom tubular heating elements ... duct...

p r o c e s s d u c t h e a t e r s

Introduction

Heatrex designs and manufactures commercial and industrial electric heating and control systems that set the industry standard for excellence. The companys heating solutions reflect more than 80 years of innova-tion, product quality and efficient service.Heatrex Process Duct Heaters are your solution for heating forced air in industrial systems efficiently and economically. Our reputation has been built on cus-tom designed heaters where we control the complete design and manufacturing process. This includes the manufacture of heating elements; complex metal framing; control enclosures and electronic controls. Whatever your application, Heatrex can design and provide a high quality process duct heater to meet your requirements.

Table of Contents

Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5

open Coil Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Finned Tubular Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Tubular Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

250 F Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Engineering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-9

Selection Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Choosing the Correct Watt Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Circuit Sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Pressure Drop Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Calculating KW Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Special Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-13

Custom Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14-16

Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17-20

Heater Listings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21-39

250 F Maximum outlet Air Temperature . . . . . . . . . . . . . . . . . . . . . . .21-24




1200 F Maximum outlet Air Temperature . . . . . . . . . . . . . . . . . . . . . .37-39

Control Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40-42

How to order . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

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Construction

All Heatrex process duct heaters are designed and built with the following construction features to assure the highest quality and long service life.

Minimum bracket spacing reduces coil sag.

Galvanized steel framing up to 250 F outlet air; Aluminized steel framing up to 600 F outlet air; 304 stainless steel for higher temperatures.

Heavy gauge steel flange with pre-drilled mounting holes furnished for 400 F outlet air and higher.

Stainless steel terminal hardware and 10-32 threaded studs assure reli-able connections.

Louvered terminal box cover keeps connections and wiring at safe temperatures.

Pressure connectors welded or bolted to bus bars furnished for field wiring of 8 gauge and heavier.

Removable bus bars are secured with stainless steel nuts and shakeproof wash-ers.

1 of insulation in terminal box standard for outlet temperatures up to 750 F. 4 insulation below mounting flange stan-dard for 1200 F construction. Optional for other constructions.

Multiple concentric knockouts on all sides of the terminal box for convenient conduit entry.

80/20 Nichrome coils for minimum sag and maxi-mum life.

Rib-strengthened brackets with formed gussets at cor-ners for rigidity.

Open Coil Heaters


Construction

Aluminized steel support brackets with flared openings allow elements to expand and contract smoothly.

Elements are .475 diameter, 304 stainless steel. Corrugated fins, 1-1/8 O.D. are the same material.

Heavy steel or stainless steel flange with pre-drilled mounting holes fur-nished for 400 F outlet air and higher.

Multiple concentric knockouts on all sides of the terminal box for conve-nient conduit entry.

Stainless steel terminal hardware and 10-32 threaded studs assure reliable connections.

Removable bus bars are secured with stainless steel nuts and shakeproof washers.

Terminal box may be side or top mounted.

Louvered terminal box cover keeps connections and wiring at safe tem-peratures.

Individually replaceable elements mounted to the terminal flange with push nuts.

Optional 4 insulation below mounting flange cuts energy losses through oven walls, keeps electrical connections cool. 1 of insulation in terminal box is stan-dard for 400 and 600 F outlet air.

1/2 diameter steel rods tie the assem-bly together in a rigid, yet expandable, mode.

Open framework allows universal mounting. Use with horizontal or vertical airflow.


Finned Tubular Heaters

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Construction

Tubular Heaters

Heavy steel or stainless steel flange with pre-drilled mounting holes.

Multiple concentric knockouts on all sides of the terminal box for convenient conduit entry.

Louvered terminal box cover keeps connections and wiring at safe tem-peratures.


Removable bus bars are secured with stainless steel nuts and shakeproof wash-ers.

Individually replaceable elements mounted to the terminal flange with push nuts.

Stainless steel terminal hardware and 10-32 threaded studs assure reli-able connections.

304 stainless steel support brackets with contoured openings to allow the elements to expand and contract smoothly.

1/2 diameter steel rods tie the assembly together in a rigid, yet expandable, mode.

Recompressed bends eliminate hairline cracks in insulation, extending element life.

Elements are .475 diameter Incoloy 800 sheath.

Unique bending configuration reduc-es the number of element terminals by more than half, lowering terminal box temperatures.

Terminal box may be side or top mounted.

1 of insulation in terminal box standard for outlet temperatures up to 750 F. 4 insulation below mounting flange standard for 1200 F construction. Optional for other constructions.

Open framework allows universal mounting. Use with horizontal or vertical airflow.

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Construction/Typical Applications

5

Aircraft Manufacturing Air Curtains Air Drying Annealing Booster Heating Baking Batch Heating Chemical Processing Cooking Core Drying Cryogenic Exhaust

Gas Heating

Curing Dehumidification Dehydrating Drying Exhaust Gas Heating Film Drying Finishing Systems Food Processing Fruit Ripening Heat Recovery Supplement Heat Treating

Hopper Heating Ink Drying Laboratory Testing Make-up Air Heating Metal Finishing Motor Winding Burnoff Paint Baking/Drying Pharmaceutical

Manufacturing Plastic Curing Preheating Reheating

Roasting (nut, coffee, corn, etc.)

Semi-Conductor Manufacturing

Sterilizing Standby Heating Textile Drying Varnish Drying Wire Manufacturing

250 F ConstructionLow temperature heaters, suitable for 250 F maximum outlet air, are available in both open coil and finned tubular constructions. They are identical to the heaters described on pages 2 and 3 except for the following features.

The steel flange is omitted. The heater is attached to the oven or duct wall with sheet metal screws through the base of the terminal box.

Individually replaceable finned tubular elements are flange mounted.

The terminal box has 1 of insulation.

A galvanized steel channel frame is provided on three sides, with the element support brackets welded to the frame.

Heatrex Process Duct Heaters are installed in plenums, ducts or pipes to heat forced air in industrial equipment and systems. A wide variety of heater designs and sizes are avail-able to provide outlet air temperatures up to 1200 F. The air can be either recirculated or fresh. Recirculated air is used to reduce power consumption and heater size.

Fresh air is used when ventilation of the process is necessary.

Process duct heaters are installed in ovens, furnaces, autoclaves, dryers, conveyor systems, pressure vessels, and other equip-ment to supply the precise amount of clean heat for:

Typical Applications


Selection Guide

Factor Open Coil Finned Tubular Tubular

1200 F maximum

The lightest of all three types.

Resistance coils, exposed directly to airstream, run cooler than coils imbedded in sheathed elements.

Lowest pressure drop due to large percentage of open space.

Large clearances between live parts and ground enable open coil heaters

to withstand severe applications.

Since element is electrically live, do not use if element may be

touched by conductive material or personnel.

Use only with clean air free ofconductive particles or water spray.

Open coil heaters are mostsusceptible to damage due to

physical abuse.

Airflow must be uniformlydistributed to prevent hot spots.

Pressure plates can help evenout airflow.

Maximum air velocity of 2500 SFPM

Open coil heaters respond quickly to step control because of low

thermal inertia. This can produce temperature fluctuations if control

system does not compensate.

For most applications, open coil heaters are more economical

because manufacturing operations are simpler.

600 F maximum

Heavier than open coil. Additional support required for horizontally

mounted units, especially for extra long heaters.

Coils run hotter than open coil, but cooler than tubular due to heat

transfer effect of fins.

Lower pressure drop than tubular, but higher than open coil.

Clearances between live parts and sheath are small, but filled with

compacted insulation.

Because the coil is enclosed in a metal sheath, shock hazard due to

contact is eliminated.

Can be used with air containing water droplets or conductive par-ticles unless particles are likely to

build up between fins.

Finned tubular heaters can with-stand more physical abuse than

open coil.

Finned tubular heaters are most tolerant of nonuniform airflow.

Hot spots tend to be dissipated by sheath and fins.


High thermal inertia makes finned tubular heaters slower to respond,

but can produce more uniform temperatures if control system is

properly designed.

Generally more expensive than open coil, but less expensive than

tubular because watt densities are higher.

1200 F maximum

Heavier than open coil. Additional support required for horizontally

mounted units, especially for extra long heaters.

Coils run hotter than open coil or finned tubular. Temperatures are kept within safe limits by reducing

watt densities.

Highest pressure drop becauseof high percentage of space

occupied by tubes.

Clearances between live parts and sheath are small, but filled with

compacted insulation.

Because the coil is enclosed in a metal sheath, shock hazard due to

contact is eliminated.

Can be used with virtually any type of air quality.

Tubular heaters are leastsusceptible to damage due to

physical abuse.

Less susceptible to hot spots than open coil, but more susceptible

than finned tubular.


Thermal inertia is greater than open coil, but less than finned tubular.

Generally most expensive of the three because of conservative, high

temperature design.

Outlet Air Temperature

Weight

Coil Temperature

Pressure Drop

Electrical Clearance

Safety

Air Quality

Mechanical Stability

Airflow Uniformity

Velocity

Controllability

Cost

Engineering Information

Table I


Choosing the Correct Watt DensityWatt density (watts/sq. in. of element surface area) is a criti-cal factor in heater selection. If the watt density is too high for the application, the heater will fail prematurely. If the watt density is too low, the heater cost will be high. Proper watt density is a function of three variables: Heater construction, maximum outlet air temperature and air velocity. Having chosen the construction, watt density can be determined from Table II below, based on temperature and velocity.

Circuit SizingAll standard heaters in the listings have circuits that draw a maximum of 48 amps. This enables the use of 50 amp con-tactors and 60 amp fuses which are generally less expensive than higher rated devices.

For certain applications, however, it may be desirable to have larger circuits e.g. for use with large SCR controls or to reduce the number of incoming power conductors. In these cases, larger circuits up to approximately 300 amps can be provided. However, in the tubular and finned tubular con-structions, circuiting must be consistent with the number of ele-ments shown in the listings.

The heater listings are labeled for various outlet air tem-peratures. The assumed minimum velocity and design watt density are shown at the top of each table. If the velocity in your application is lower than indicated in the heater listing, choose a lower watt density from Table II. If your velocity is substantially higher than shown in the heater listing, check it against the values in the table. You may be able to use a higher watt density at a lower price.


Maximum Watt Densities At Outlet Temperatures And Velocities Shown

Maximum Watt Densities At Outlet Temperatures And Velocities Shown

Open Coil Construction Finned Tubular Construction

Outlet Temperature Outlet Temperature

250 F 400 F 500 F 600 F 750 F 1000 F 1200 F 250 F 400 F 500 F 600 F

300 55 45 35 30 25 15 10 45 40 35 30

600 60 55 50 45 30 20 10 55 50 40 35

900 65 65 60 55 35 25 15 65 65 55 45

1200 65 65 65 65 40 30 20 65 65 60 55

1600 65 65 65 65 55 40 25 65 65 65 65

2000 65 65 65 65 65 50 30 65 65 65 65

Tubular Construction

Outlet Temperature 750 F 1000 F 1200 F

13 6 3

22 12 7

25 18 12

30 22 16

40 30 22

45 35 25

400 F 500 F 600 F

20 18 16

24 22 22

28 25 25

30 30 30

40 40 40

45 45 45

MinimumVelocity In

Standard FPM

MinimumVelocity In

Standard FPM

Table II

250 F

22

28

32

35

45

45

300

600

900

1200

1600

2000



Static pressure drop as a function of air velocity is shown below. Open coil heaters have the lowest pressure drop. Smaller fan motors can often be used with this design. Pressure drop values provided in Charts A through C are based on the airflow being

parallel to the heater C dimension.

For tubular design only, consult factory for pressure drop when airflow is parallel to the H dimension.

500 800 1200 2000400 600 1000 1500

.40

.30

.25

.20

.15

.10

.08

.06

.05

.04

.03

.025

.02

.015

C =

18-3

/8

C =

14 o

r 16

C =

6, 8

or 9

.5

Max

imum

Pre

ssur

e Dr

op In

Inch

es o

f Wat

er

Velocity in SFPMChart AOpen Coil Design

300 500 800 1200 2000400 600 1000 1500

1 .6

1 .2

1 .0

.80

.60

.50

.40

.30

.20

.16

.12

.10

.08

.06

.05

.04

.03

C =

18-3

/8

C =

9 .5

Velocity in SFPM

Max

imum

Pre

ssur

e Dr

op In

Inch

es o

f Wat

er

Chart CTubular Design

300 500 800 1200 2000

300 500 800 1200 2000

400 600 1000 1500

400 600 1000 1500

.80

.60

.50

.40

.30

.20

.16

.12

.10

.08

.06

.05

.04

.03

TUBU

LAR

FINN

ED T

UBUL

AR

oPEN

CoI

L

Velocity in SFPM

Max

imum

Pre

ssur

e Dr

op In

Inch

es o

f Wat

er

Chart DComparative Pressure Drop Through All Three Designs at 9.5 C Dimension

Chart BFinned Tubular Design

.50

.40

.30 .25

.20

.15

.10

.08

.06

.05

.04

.03

.025

.02

.015

C =

9 .5

or 1

6

C =

6 o

r 8

Velocity in SFPM

Max

imum

Pre

ssur

e Dr

op In

Inch

es o

f Wat

er

Pressure Drop Curves



9

Calculating KW RequirementsOnce the volume of air in standard cubic feet per minute (SCFM) and the required temperature rise in F ( T) are known, the required kilowatt rating (KW) of the heater can be determined from the following formula:

Note that CFM is given at standard conditions (SCFM): 80F and normal atmospheric pressure of 15 psi. The CFM at a higher pressure (P) and inlet air temperature (T) may be cal-culated as follows:

Example:

A drying oven, operating at 25 psia (10 psi gauge pressure), recirculates 3000 cubic feet of air per minute through a heater which raises its temperature from 350 to 400 F.

To select an appropriate heater:

Step 1: Convert 3000 CFM at 25 psia and 350 F to CFM at standard conditions using the above formula:

Step 2: Calculate the required KW:

Step 3: Calculate the maximum heater face area (WxH) that will result in an air velocity above the minimum required for standard heater listings:

The 400 F listing on pages 25 through 28 are based on 900 SFPM velocity. Thus, the

Step 4: Select a heater rated for at least 52 KW with a face area of 3.7 sq. ft. or less.

On page 26 is a group of 54 KW heaters, the first of which has an area of 12 x 30 = 1.0 x 2.5 = 2.5 sq. ft. This item is therefore appropriate. Select either Catalog No. HX-166N-635-401U (finned tubular) or HX-165N-335-401U (open coil). Both are rated 65 watts/sq. in.

Note: If a larger face area is required, a lower watt density must be selected. For example, if the heater face is 24 wide x 30 high, the velocity will be:

Per Table II, 400 F outlet air and 600 SFPM velocity require maximum watt densities of 55 watts/sq. in. for open coil and 50 watts/sq. in. for finned tubular. Since the 600 F listings on pages 29 through 32 are based upon watt densities of 55 and 45 for open coil and finned tubular respectively, a heater may be selected from this table. The 54 KW item, Catalog No. HX-166N-848-601U (finned tubular) or Catalog No. HX-165N-148-601U (open coil) may be used.

SCFM x T3193

KW = = 52 KW3333 x (400 F 350 F)3193

KW =

SCFM = CFM x

SCFM = 3000 x = 3333 SCFM

x

x

P15

25 psia15

540(350 F + 460)

540(T+460)

= = 3 .7 sq . ft . 3333 SCFM900 SFPMMaximumFace Area

= = 667 SFPM 3333 SCFM2 .0 x 2 .5 3333 SCFM

24 x 30

Special Features


A wide variety of special features can be incorporated into Heatrex process duct heaters. Please contact us if you have other requirements.

Built-in Controls

(Available for heaters operating up to 150 F outlet air temperature.)

Built-in contactors, fuses, control transformers, and disconnect switches save installation labor and provide single source responsibility for the heater-control package.

Built-in Thermostat


For automatic control of outlet air temperature. Adjustable over a range of 60-250 F. Outlet tem-perature will be lower than set point as the thermostat senses heat from elements as well as outlet air. Do not use where outlet air temperature will exceed 150 F. May also be used as an automatic high tem-perature thermal cutout.

Built-in Combination Thermostat/Thermal Cutout


Control normally cycles the heater on and off, but shuts the heater down until reset button is pressed if temperature rise is more than 50 F above the control set point. (60-250 F range).

Remote Mounted Thermostats

For air temperature control or high temperature thermal cutout protection, a bulb and capillary type thermostat can be mounted in a cool location up to 8 away from the heater. A well is provided to mount the thermostat bulb into the airstream. Two models are available:

DA1-6E96: 200-550 FDA1-6F96: 300-700 F

Built-in Thermocouple

Built-in sheathed thermocouple available for high temperature limit. This can be mounted in the airstream or clamped to a tubular/finned tubular element to prevent overheating.

Built-in Airflow Switch


A diaphragm-operated differential pressure switch normally prevents the heater from operating unless the air is flowing. It senses pressure between process air and the terminal housing.

Special Features

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Moisture-Resistant Element Seal

RTV or epoxy seals are inserted into each end of tubular or finned tubular elements. Recommended when heater may be stored in high humidity or where terminals are exposed to high humidity during operation.

Flanged Duct Mounting

For attaching heater to external duct flanges. No internal support required. Note that heater face dimensions W and H match the inside dimensions of the duct. While integral flange design is a standard option on the 250 F Construction, other heaters can be supplied with separate flange mounted plenum sections where required.

Flanged Terminal Box

A 1 full flange at end of terminal box is available for mounting heater. Especially useful when heater is mounted inside an oven, where ready access to electrical connections and mini-mum terminal box size are desirable. No terminal box cover is supplied.

Isolated Junction Box

Power connections are housed in a separate isolated junction box, factory connected to heating element terminals. Used where field wiring is not suitable for high ambient temperatures.

Angle Iron Frame

(Available for all tubular and finned tubular heaters except those with 250 F Construction.)

Support rods are replaced by heavy angle iron welded to element supports and terminal box. May increase C and H dimensions. Specify steel or stainless steel angle iron.

Special Features

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Special Materials

Nonstandard fin, sheath and frame materials available for special applications.

Finned tubular elements available with Monel sheath and fins. Tubular elements available in Monel, 304 and 316 stainless steel and Inconel sheath. Other element diameters and sheath materials are available to meet your custom design requirements. Stainless steel frames available for all constructions.

Nonstandard Circuiting

Additional circuits available on standard heaters. However, number of circuits must be consistent with number of elements in tubular and finned tubular constructions. Number of cir-cuits shown in standard listings can also be reduced for high amperage SCR control.

Insulation Under Mounting Flange

Insulation is furnished under mounting flange to save energy and reduce terminal housing temperatures. This is standard on 1200 F Construction and optional on all others.Dust-Tight Terminal Box

For dirty environments. Boxes are welded, stainless steel with hinged, latched cover and Scru-tite hubs for incoming power.

Insulation under the mounting flange is required for all heaters operating above 250 F outlet air.

Special Wattage, Voltage and Dimensions

Heatrex specializes in custom designed process duct heaters.

Voltages up to 600V are available in single or three phase.

Airtight Terminal Box

(Available for all tubular and finned tubular heaters except those with 250 F Construction.)

Terminal box isolated from the duct or oven with compression fittings on each element to prevent leakage of process air into terminal box.

N INSULATIoN

H

W6

C


Special Features

Special Cold Ends

To clear oven wall or to place active portion of heating element well into airstream, long cold ends may be provided. All heat-ers have 2 cold ends as standard.

Pressure Plate

A 40% open pressure plate on the inlet side of the heater evens out the airflow pattern where it is not normally uniform. A pressure plate significantly increases the pressure drop across the heater, as shown in the chart.

Top Mounted Heater Construction

A special top mounted design is available on open coil heaters. This feature allows easier installation when there are space restrictions on the sides of the heater but access is available from the top. In these applications, the coils are strung hori-zontally for proper heating of the airflow.

1 .0

.80 .60

.50

.40 .30

.25

.20

.15

.10

.08 .06

.05

.04 .03

.02

.015

300 500 800 1200 2000200 400 600 1000 1500

Velocity in SFPM

Max

imum

Pre

ssur

e Dr

op In

Inch

es o

f Wat

er

H

W

6"

N" INSULATION

Front View

C

MOUNTING FLANGE

Side View

Chart EPressure Drop

H

H

W

C

6

N INSULATIoN

MoUNTING FLANGE

W

C

6

CoLDEND

Side View

Front View


Custom Designs

Heatrex has the ability to customize heaters for unusual or special applications. The following are a few examples of our construction and design capabilities.

Crucible PreheaterFour flanged tubular heaters are mounted into an insulated cap and factory wired to a common junction box (not shown) in the center. The heaters preheat the air in a crucible to 1000 F before molten aluminum is poured into it. This energy saving design replaced an open gas flame which was shot into the crucible before pouring. The low watt density elements generate no heat in the U-bent portions so as to concentrate the heat in the crucibles vertical walls. Terminal boxes are ventilated to prevent overheating of internal wir-ing. One set of incoming power lines feeds the entire 60 KW load.

Autoclave HeaterThis 1500 KW heater accommodates a fan in the center that can either draw or blow air through the open coils. The assembly is typically mounted on the door of an airtight batch oven, eliminating duct work. The design assures uniform air distribution over the coils without a pressure plate or other air straightening device. Units can be built to customer-specified KW ratings, inside and outside diameters, and for outlet tem-peratures up to 750 F. Field power connections are made to terminals inside the donut.

Two of 15 modules, each rated 624 KW, producing a total of 9360 KW in an autoclave installed in an aircraft facility. Structural components of the aircraft are made from light-weight composites such as boron or graphite fibers bonded with epoxy. Thin sheets of the metal are cut with computer-ized cutting equipment, layered in a crisscross pattern, then bonded together in the autoclave at pressures up to 300 psi and temperatures up to 1300 F. A nitrogen atmosphere prevents combustion of volatile vapors given off as the epoxy cures. Severe space limitations dictated a unique bus bar pat-tern, resulting in terminals at both ends of each module.

Processing Agricultural ProductsThis assembly of heaters, angle iron rack frame and panel-boards is typical of systems built to process agricultural prod-ucts. Applications include drying barley for malt production and dehydrating alfalfa for animal feed. Ratings up to 4300 KW in a single assembly and multi-heater installations up to 72,000 KW have been furnished. The finned tubular design is usually recommended because of environmental job con-ditions. Heatrex designs and builds all components of the system, giving the owner a turn-key installation. Electric heat is normally preferred over gas since there are no products of combustion, making the end product suitable for human con-sumption.

Custom Designs

Custom Designs


Ripening Room HeaterHeater installed in a package unit that maintains proper temperature and humidity in produce storage rooms. Typical applications include banana ripening and potato or apple stor-age. Stainless steel finned tubular elements, complete with moisture-proof seals, withstand corrosion caused by water carry-over from the cooling coil and gases released in the rip-ening process. Heater has built-in controls.

Ink DryingFiltered room air passes over this open coil heater (terminal box only shown) through a high speed blower. The 250 F pressurized air is then piped to a printing press where it bom-bards the web at a high velocity to evaporate and scrub off ink solvents. Solvent laden air is vacuumed away from the press and back to the dryer by a second high speed blower, then exhausted through a vent.

Environmental Test Chamber HeaterThis 543 KW heater operates in an environmental chamber where aircraft components are tested at temperatures up to 1475 F. Stainless steel rods are welded to the bus bars link-ing the elements together to form circuits of various KW rat-ings. The rods are bent at 90 and project through the wall of the test chamber so that incoming power connections can be made in a cool location. The entire unit is made from stainless steel.

Paint Curing SystemPart of a shipment of 26 identical tubular oven heaters, rated 240 KW each, to dry paint at temperatures ranging from 300 F to 700 F. Eighteen heaters are installed in a 4320 KW electro-coat cure oven and the remaining eight in a 1920 KW flow-coat cure oven at a tractor fabrication plant. Factory fur-nished vertical bus bars connect directly to bus duct feeding the entire system. Heating elements are individually replace-able and are secured to the insulated terminal box with com-pression fittings to prevent air leakage. Each heater slides into the oven on roller bearings to facilitate maintenance. Each oven is divided into several zones and the entire load is SCR controlled.

Installation Guidelines


Custom Designs

Bonding OvenThis 13 foot long, 550 KW heater is installed in a batch oven for drying sealants and curing adhesives on parts wrapped in fiberglass for the aerospace industry. This unit replaced a series of open coil heaters, whose coils shorted out due to fiberglass filings in the airstream. It heats 39,000 SCFM of air to 610 F.

Load BankThis 126 KW open coil load bank was built to test large stand-by generators. With the use of a separate control panel, the 22 circuit design allows for testing of variable resistance loads at different RPM levels. Routine testing with load banks con-firms that generators are functioning properly and are ready for use when needed. This is critical for facilities that cannot be without power, such as hospitals, police stations, fire sta-tions or prisons. Load banks are also used in the testing of main or stand-by generators found on commercial or military aircraft and nuclear submarines.

High Temperature Core ConstructionThis unit produces 1400 F air for hot forming titanium used in aircraft components. Open coil elements are wound on grooved, ceramic cores, resulting in an extremely compact design: The heated chamber produces 60 KW, but measures only 18 cubed. The heater slips through the top of the fur-nace, with an insulation plug under the mounting flange that matches the thickness of the furnace wall. Electrical connec-tions are made externally to stainless steel lugs, factory weld-ed to stainless bus bars that interconnect the elements below.



Open Coil Heaters must be mounted horizontally for either horizontal or vertical airflow.

Tubular and Finned Tubular Heaters may be mounted either horizontally or vertically. When mounted horizontally, the air-flow may be either horizontal or vertical. When mounted ver-tically, the airflow must be horizontal. All tubular and finned tubular heaters, except those rated for 250 F air, may be rotated 90 about a horizontal axis to fit the available space. For example, a heater 16 high (H dimension) and 9.5 deep (C dimension) may be mounted with either the 9.5 dimension or the 16 dimension parallel to the airflow.

Mounting

Open Coil Heater Mounted For Horizontal Airflow

Horizontally Mounted Tubular Or Finned Tubular Heater

Vertically Mounted Tubular Or Finned Tubular Heater

Open Coil HeaterMounted For Vertical Airflow




Support

If the heater is mounted through an opening in an insulated wall, special precautions must be taken to insure that the entire heated length is in the airstream. Otherwise, the elements shadowed by the insulation will overheat and burn out.

Open Coil heaters designed for 1200 F air are provided with 4 of insulation under the mounting plate. If the insulated oven wall is thicker than 4, additional insulation should be provided in the heater. Heaters rated for lower outlet air temperatures may also be provided with insulation under the mounting plate or with extended terminal cold sections to clear the oven wall. The standard open coil construction will clear up to 2 of insulation without modification.

Finned Tubular heaters may also be provided with insulation under the mounting plate or extended cold sections. Heaters will clear 2 of insulation without modification.

Tubular heaters rated for 1200 F outlet air are provided with 4 of insulation under the mounting flange, which should be extended for heavier oven walls. Heaters rated for 750 F outlet air may also be provided with 4 of insulation under the mount-ing plate, or may safely be installed through a wall up to 2 thick without modification.

Insulation

Low Temperature Heaters, suitable for 250 F maximum outlet air, are attached to the ductwork or oven wall with sheet metal screws through the base of the terminal box, as shown.

Higher Temperature Heaters, those rated for 400 F air and higher, must be bolted to the duct or oven wall using the bolt holes provided in the steel flange at the base of the terminal box. Weld nuts or captive nuts may be provided in the wall or a mating flange can be provided in the field.

All Horizontally Mounted Heaters, except those weighing less than 25 lbs., should be supported inside the oven or duct with rails or hangers. Heaters mounted vertically through the top of the oven or duct need not be supported internally. However, the structure should be adequate to carry the entire heater weight.

Installation Of 250 F Heater

Installation Of Heater Rated For 400 F And Higher



19

To prevent overheating under adverse conditions, overtem-perature protection is recommended. Four types of protective devices are available:

Thermal Cutout A thermostat, set approximately 50 higher than normal operating temperature, can be built into heaters rated for 250 F maximum outlet air. The built-in thermostat or built-in combination thermostat/thermal cutout can be used for this purpose. For higher temperature heaters, a remote thermostat may be used as a thermal cutout.

Built-in Thermocouple A thermocouple, sensing sheath or air temperature, can be wired to a remotely mounted ther-mocouple controller, set approximately 50 F above normal operating temperature. The controller then acts as a thermal cutout.

Built-in Airflow Switch A differential pressure type airflow switch may be built into 150 F heaters. By sensing the dif-ference in pressure between the process air and the outside atmosphere, it will shut down the heater when there is a sud-den drop in process pressure.

Fan Interlock Relay A relay interlocking the fan motor with the heater control circuit will shut down the heater if there is no power to the fan. Note, however, that this device does not protect against a stalled motor nor against a blockage in the airstream that would result in little or no airflow, even though the fan is running.

Overtemperature ProtectionAll heaters in the listings are designed for 480 volts, three phase. Therefore, three power leads must be brought into the heater for each circuit through the knockouts provided in the terminal box. The number of circuits is shown in the listings. The current drawn by each circuit is calculated as follows:

All wiring should be per the National Electrical Code and any special provisions in local codes. Wiring insulation must be suitable for the terminal box ambient temperature as deter-mined from Chart F. Note that lower temperature wiring insulation may be used on heaters with insulation under the mounting flange.

Field Wiring

Line Current = Circuit KW x 1000

Voltage x 1.73

Chart FTerminal Box Temperature

Installation Guidelines Heater Listings

Heater Adjacent To Transition

Heater Partially Blocked By Filter Or Frame Member

Heater Too Close To Elbow

Heater Too Close To Fan


To prevent hot spots, airflow must be uniformly distributed across the heater face. These drawings illustrate typical heat-er misapplications which result in nonuniform airflow. If one or more of these conditions cannot be avoided, consult Heatrex for assistance. In most cases we can provide a pressure plate or nonheated zones in the heater to overcome these prob-lems.

Airflow Uniformity

Heater Listings

250 F Maximum Outlet Air Temperature

4.56999

121313181818181822242727

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)

Finned Tubular Construction65 Watts/Sq. In.

Open Coil Construction65 Watts/Sq. In.

Heater Listings - 250 F at 900 SFPM Minimum Airflow

1216122024161230121620243612161220

88

1288

12168

201612128

24203016

88888888888888888

1010101010101510151515151520202520

1015201515202520303025252535354535

HX-166N-401-201UHX-166N-402-201UHX-166N-403-201UHX-166N-404-201UHX-166N-405-201UHX-166N-406-201UHX-166N-407-201UHX-166N-408-201UHX-166N-409-201UHX-166N-410-201UHX-166N-411-201UHX-166N-412-201UHX-166N-413-201UHX-166N-414-201UHX-166N-415-201UHX-166N-416-201UHX-166N-417-201U

HX-165N-501-201UHX-165N-502-201UHX-165N-503-201UHX-165N-504-201UHX-165N-505-201UHX-165N-506-201UHX-165N-507-201UHX-165N-508-201UHX-165N-509-201UHX-165N-510-201UHX-165N-511-201UHX-165N-512-201UHX-165N-513-201UHX-165N-514-201UHX-165N-515-201UHX-165N-516-201UHX-165N-517-201U

33633693

129663

1512189

11111111111111111

11111111111111111


Heaters are rated at 480 volts, 3 phase.

Finned Tubular Open Coil

HEATER DEPTH

TERMINAL BOXWIDTH (C + 3)

H HH+2H+2

W

C

M

W6 6


Heater Listings Heater Listings



2727303136363636364040424545454850545454545454586063636366676772727272727678

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




2430161212162024361230161220241612121620243036121612202416123012162024361216

1612243438302020124216342424243830304230302016342434343430382438303838204234

888888888888

16888

161688888

16161688

16168

1616888

1616

2015202530252025203525302525303535354030353025353035354040403540404045304545

35354050555040454060455565505065707570606055558575907070809565

1009080806565

105

HX-166N-418-201UHX-166N-419-201UHX-166N-420-201UHX-166N-421-201UHX-166N-422-201UHX-166N-423-201UHX-166N-424-201UHX-166N-425-201UHX-166N-426-201UHX-166N-427-201UHX-166N-428-201UHX-166N-429-201UHX-166N-430-201UHX-166N-431-201UHX-166N-432-201UHX-166N-433-201UHX-166N-434-201UHX-166N-435-201UHX-166N-436-201UHX-166N-437-201UHX-166N-438-201UHX-166N-439-201UHX-166N-440-201UHX-166N-441-201UHX-166N-442-201UHX-166N-443-201UHX-166N-444-201UHX-166N-445-201UHX-166N-446-201UHX-166N-447-201UHX-166N-448-201UHX-166N-449-201UHX-166N-450-201UHX-166N-451-201UHX-166N-452-201UHX-166N-453-201UHX-166N-454-201UHX-166N-455-201U

HX-165N-518-201UHX-165N-519-201UHX-165N-520-201UHX-165N-521-201UHX-165N-522-201UHX-165N-523-201UHX-165N-524-201UHX-165N-525-201UHX-165N-526-201UHX-165N-527-201UHX-165N-528-201UHX-165N-529-201UHX-165N-530-201UHX-165N-531-201UHX-165N-532-201UHX-165N-533-201UHX-165N-534-201UHX-165N-535-201UHX-165N-536-201UHX-165N-537-201UHX-165N-538-201UHX-165N-539-201UHX-165N-540-201UHX-165N-541-201UHX-165N-542-201UHX-165N-543-201UHX-165N-544-201UHX-165N-545-201UHX-165N-546-201UHX-165N-547-201UHX-165N-548-201UHX-165N-549-201UHX-165N-550-201UHX-165N-551-201UHX-165N-552-201UHX-165N-553-201UHX-165N-554-201UHX-165N-555-201U

96

1521241812126

279

21301515243336271818129

393042212133451548362424125139

11111111122222222222222222222232222233

111111111222222222222222222222

22222222

Heater Listings




8181818184909090909595

100100102108108108108108117117122126126126135135135135144144144150153153162162162162

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




122024301616202436301620241616202430362024302024362020243020243630202420243036

424242303438242424343830304242303038303434423434343838382438383830424242423042

16888

1616161688

1616161616161688

16168

16168

1616161616168

1616161616168

454550454550404540505045555555455555505060605560556055655555656065607060706565

110858580

10011095958090

11510510512013011011010095

120120110125130110135135135125145145125135155155160160145135

HX-166N-456-201UHX-166N-457-201UHX-166N-458-201UHX-166N-459-201UHX-166N-460-201UHX-166N-461-201UHX-166N-462-201UHX-166N-463-201UHX-166N-464-201UHX-166N-465-201UHX-166N-466-201UHX-166N-467-201UHX-166N-468-201UHX-166N-469-201UHX-166N-470-201UHX-166N-471-201UHX-166N-472-201UHX-166N-473-201UHX-166N-474-201UHX-166N-475-201UHX-166N-476-201UHX-166N-477-201UHX-166N-478-201UHX-166N-479-201UHX-166N-480-201UHX-166N-481-201UHX-166N-482-201UHX-166N-483-201UHX-166N-484-201UHX-166N-485-201UHX-166N-486-201UHX-166N-487-201UHX-166N-488-201UHX-166N-489-201UHX-166N-490-201UHX-166N-491-201UHX-166N-492-201UHX-166N-493-201UHX-166N-494-201U


542727184245303015214833335154363624183939274242214545453048482433515154543627

333333333433333334344544444454446555565

333333333333333333333444

444444444445555

Heater ListingsHeater Listings



175180189198202216216230234243252270288306324

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




303630363030363036303636363636

342434303838304234423438384242

161616161616161616161616161616

70607075808075858585859095

100100

155150165165180190180200195210205220235245260

HX-166N-495-201UHX-166N-496-201UHX-166N-497-201UHX-166N-498-201UHX-166N-499-201UHX-166N-500-201UHX-166N-501-201UHX-166N-502-201UHX-166N-503-201UHX-166N-504-201UHX-166N-505-201UHX-166N-506-201UHX-166N-507-201UHX-166N-508-201UHX-166N-509-201U

HX-165N-595-201UHX-165N-596-201UHX-165N-597-201UHX-165N-598-201UHX-165N-599-201UHX-165N-600-201UHX-165N-601-201UHX-165N-602-201UHX-165N-603-201UHX-165N-604-201UHX-165N-605-201UHX-165N-606-201UHX-165N-607-201UHX-165N-608-201UHX-165N-609-201U

393042334548365139544245485154

757688697978899

555566666777889


Heater Listings



Open Coil

4.56999

1213131818181818

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




12161220241612301216202436

88

1288

12168

201612128

6666666666666

10101015151515151515152020

15152015152530203530252520

HX-166N-601-401UHX-166N-602-401UHX-166N-603-401UHX-166N-604-401UHX-166N-605-401UHX-166N-606-401UHX-166N-607-401UHX-166N-608-401UHX-166N-609-401UHX-166N-610-401UHX-166N-611-401UHX-166N-612-401UHX-166N-613-401U

HX-165N-301-401UHX-165N-302-401UHX-165N-303-401UHX-165N-304-401UHX-165N-305-401UHX-165N-306-401UHX-165N-307-401UHX-165N-308-401UHX-165N-309-401UHX-165N-310-401UHX-165N-311-401UHX-165N-312-401UHX-165N-313-401U

33633693

129663

1111111111111

1111111111111


Mounting Hole Details Mounting hole patterns depend on heater C and H dimensions. Mounting holes are 9/32 diam-eter, centered 3/8 from the outside edge of the plate.

AIRFLOW DIRECTION

AIRFLOW DIRECTION

KNOCKOUTS ON ALL SIDES


H

W

H

C

C

W

6

6

Finned Tubular

Heater Depth CMtg. Hole Centers K

Heater Height HNo. of Spaces P

Mtg. Hole Centers Q

628

23

9.53.512

33.75

163

4.25

203

5.25

243

5.75

305

4.88

347

4.38

387

4.88

427

5.25

K

Q

K

C+2

H+2

P x Q




22242727272730313636363636404042454545485054545454545458606363636667677272727272

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




12161220243016121216202436123016122024161212162024303612161220241612301216202436

24203016161224343830202012421634242424383030423030201634243434343038243830383820

6666666666666666

9.5666

9.59.566666

9.59.59.566

9.59.56

9.59.5666

15202020202020202525202525252530252530303030353035303030303035403535353535354035

454055353530506070604545357545657555557590958570705550

10085

105808095

11570

120105909065

HX-166N-614-401UHX-166N-615-401UHX-166N-616-401UHX-166N-617-401UHX-166N-618-401UHX-166N-619-401UHX-166N-620-401UHX-166N-621-401UHX-166N-622-401UHX-166N-623-401UHX-166N-624-401UHX-166N-625-401UHX-166N-626-401UHX-166N-627-401UHX-166N-628-401UHX-166N-629-401UHX-166N-630-401UHX-166N-631-401UHX-166N-632-401UHX-166N-633-401UHX-166N-634-401UHX-166N-635-401UHX-166N-636-401UHX-166N-637-401UHX-166N-638-401UHX-166N-639-401UHX-166N-640-401UHX-166N-641-401UHX-166N-642-401UHX-166N-643-401UHX-166N-644-401UHX-166N-645-401UHX-166N-646-401UHX-166N-647-401UHX-166N-648-401UHX-166N-649-401UHX-166N-650-401UHX-166N-651-401UHX-166N-652-401UHX-166N-653-401U


151218996

1521241812126

279

21301515243336271818129

39304221213345154836242412

1111111111111222222222222222222222322222

111111111111122

2222222222222222222222222


Heater Listings



76788181818184909090909595

100100102108108108108108117117122126126126135135135135144144144150153153162162162

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




12161220243016162024363016202416162024303620243020243620202430202436302024202430

42344242423034382424243438303042423030383034344234343438383824383838304242424230

9.59.59.5666

9.59.59.59.566

9.59.59.59.59.59.59.566

9.59.56

9.59.56

9.59.59.59.59.59.56

9.59.59.59.59.59.5

35403540454540453545404545455045454550505050555550555555556555556560656070607065

13011013510010085

1201301001008095

135115115145150120120110100135135120140140115150150150125160160130140170170180180150



51395427271842453030152148333351543636241839392742422145454530484824335151545436

3333333333343333333434454444444444455554

223333333333333

3333333444444444444444555





162175180189198202216216230234243252270288306324

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumber

CHW

KWWeight(Lbs.)




36303630363030363036303636363636

42342434303838304234423438384242

69.59.59.59.59.59.59.59.59.59.59.59.59.59.59.5

6570607075808075858585859095

100100

145165150175170190200180215195220210225240255265

HX-166N-694-401UHX-166N-695-401UHX-166N-696-401UHX-166N-697-401UHX-166N-698-401UHX-166N-699-401UHX-166N-700-401UHX-166N-701-401UHX-166N-702-401UHX-166N-703-401UHX-166N-704-401UHX-166N-705-401UHX-166N-706-401UHX-166N-707-401UHX-166N-708-401UHX-166N-709-401U

HX-165N-394-401UHX-165N-395-401UHX-165N-396-401UHX-165N-397-401UHX-165N-398-401UHX-165N-399-401UHX-165N-400-401UHX-165N-401-401UHX-165N-402-401UHX-165N-403-401UHX-165N-404-401UHX-165N-405-401UHX-165N-406-401UHX-165N-407-401UHX-165N-408-401UHX-165N-409-401U

27393042334548365139544245485154

5755656667778899

5555566666777889


Heater Listings




45

7.589

101012121515

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




1216201224162612321620

888

128

128

168

1612

66666666666

1010151015151515151515

1520202520302035254035

HX-166N-801-601UHX-166N-802-601UHX-166N-803-601UHX-166N-804-601UHX-166N-805-601UHX-166N-806-601UHX-166N-807-601UHX-166N-808-601UHX-166N-809-601UHX-166N-810-601UHX-166N-811-601U


33363639396

11111111111

11111111111

Finned Tubular

Open Coil

AIRFLOW DIRECTIONAIRFLOW DIRECTION



H

W

H

C

C

W

6

6

Heater Depth CMtg. Hole Centers K


Mtg. Hole Centers Q

628

23

9.53.512

33.75

163

4.25

203

5.25

243

5.75

305

4.88

347

4.38

387

4.88

427

5.25

Mounting Hole Details Mounting hole patterns depend on heater C and H dimensions. Mounting holes are 9/32 diam-eter, centered 3/8 from the outside edge of the plate.

K

Q

K

C+2

H+2

P x Q


Heater Listings


151618202020222424252728303030303235363636374040404545454545484850505252545556

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




401224121626201232162412162026401216122432201216261216202440123216261220241612

82012242012163012241634302016123834422016242438263042302416302024243434303034

6666666666666666666666

9.566

9.56666

9.56

9.56

9.566

9.59.5

201520152020202020202020252025252525252525252530253035303035303030303035353530

25453555503545704060508075605045858595655570959565

110105857565

11575

10580

13010095

120135



3126

151269

186

159

21181296

242127129

15302412332718159

361230153921183342

111111111111111111111111122222222222222

1111111111111111111111

11122222222222222


Heater Listings


6060606060606464646868707072727275757580808082858590909090909698

100100105105108108110

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




121620263240241216201216261224321620401626242032161620242640202024262040243226

383038302420343834424234344238303824243838423034424230244230343430243434304230

9.59.566666

9.59.56

9.59.56

9.566

9.59.56

9.56

9.59.56

9.59.59.59.566

9.59.59.59.59.56

9.59.59.5

353535353540403540403540403540454535454545704550454545455055555050455060509055

1451251101009085

105150140125160145115170120110160125105165130155145125175185150140145125140165155145175145165175165



453624181512214839275142215424184530154824273321545436302718244233304221362733

2222222222223322555223

11333353347

1157733

11

2222222222222222222222

33333333333333333


Heater Listings





112117120120120120125127130132135135135140145145150150155155160160165170170180180180190195205210215225240255270

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




20242026324024202632202440262432264024322624403226263240324032403240404040

38343830243834423430423842343830382442343842303442423830383442344238384242

9.59.59.59.59.56

9.59.59.59.59.59.56

9.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.59.5

555555555565556060656065756065657070707570708575757580858090909590

100100110110

190185200175165160195215195185220210180205220200220190235215230245215230250260245230260250280265290285300320335

HX-166N-890-601UHX-166N-891-601UHX-166N-892-601UHX-166N-893-601UHX-166N-894-601UHX-166N-895-601UHX-166N-896-601UHX-166N-897-601UHX-166N-898-601UHX-166N-899-601UHX-166N-900-601UHX-166N-901-601UHX-166N-902-601UHX-166N-903-601UHX-166N-904-601UHX-166N-905-601UHX-166N-906-601UHX-166N-907-601UHX-166N-908-601UHX-166N-909-601UHX-166N-910-601UHX-166N-911-601UHX-166N-912-601UHX-166N-913-601UHX-166N-914-601UHX-166N-915-601UHX-166N-916-601UHX-166N-917-601UHX-166N-918-601UHX-166N-919-601UHX-166N-920-601UHX-166N-921-601UHX-166N-922-601UHX-166N-923-601UHX-166N-924-601UHX-166N-925-601UHX-166N-926-601U

HX-165N-190-601UHX-165N-191-601UHX-165N-192-601UHX-165N-193-601UHX-165N-194-601UHX-165N-195-601UHX-165N-196-601UHX-165N-197-601UHX-165N-198-601UHX-165N-199-601UHX-165N-201-601UHX-165N-202-601UHX-165N-203-601UHX-165N-204-601UHX-165N-205-601UHX-165N-206-601UHX-165N-207-601UHX-165N-208-601UHX-165N-209-601UHX-165N-210-601UHX-165N-211-601UHX-165N-212-601UHX-165N-213-601UHX-165N-214-601UHX-165N-215-601UHX-165N-216-601UHX-165N-217-601UHX-165N-218-601UHX-165N-219-601UHX-165N-220-601UHX-165N-221-601UHX-165N-222-601UHX-165N-223-601UHX-165N-224-601UHX-165N-225-601UHX-165N-226-601UHX-165N-227-601U

45424836302442544233544527424836453054424854334254544536484251425448485454

574354767

11659744555745

1176656876768899

3333334444444444444445555555556666777



Heater Listings

Heaters are rated at 480 volts, 3 phase.* On this item the C dimension is 14 inches for open coil.

Heater Depth CNo. of Spaces R

Mtg. Hole Centers KHeater Height HNo. of Spaces P

Mtg. Hole Centers Q

9.5 14 18.38 2 3 4 3.5 3.88 3.88 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 1 1 2 3 3 3 3 3 3 3 3 5 5 5 5 7 7 7 7 7 2.5 3.5 3 2.75 3.25 3.75 4.25 4.75 5.25 5.75 5.75 4.5 5.25 4.88 4.88 4.38 4.88 4.88 5.38 5.25

Tubular

1015152020222530303540

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)

Tubular Construction30 Watts/Sq. In.



20-3/820-3/8

6020-3/8

3544

20-3/820-3/8

6020-3/820-3/8

684

1066

12144

1618

9.59.59.59.59.59.59.59.59.5*9.59.5

2020352025302525353035

2025203525304045305560



333633666

1212

11111111112

11111111112

Mounting Hole Details Mounting hole patterns depend on heater C and H dimensions. Mounting holes are 9/32 diameter, cen-tered 3/8 from the outside edge of the plate.

KNOCKOUTS ONALL SIDES

AIRFLOW DIRECTION

Open Coil



H

H W

W

C

C

6

6

750 F Maximum Outlet Air TemperatureAIRFLOW DIRECTION

AIRFLOW DIRECTION

K

Q

K

C+2

H+2

P x Q

Heater Listings


Heater Listings


4045454550606060677075758080909090

100100105110112120120120135135140140150157160160165180180180195200

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




3520-3/8

4460

20-3/820-3/8

356044

20-3/820-3/8

6020-3/8

3520-3/8

4460

20-3/83960

20-3/8443539604460353560443535603544606035

82086

2226148

1426268

341838181042221042222226122214263414222634163422181834

9.5*9.59.59.59.59.59.59.59.59.59.59.5*9.59.59.59.59.59.59.59.5*9.59.59.59.59.59.59.59.59.59.59.59.59.59.5*9.59.59.59.59.5

303535404045455055454550555060655565605565756070657570708570757085808575858585

456545457585656070959570

11585

1259585

14010595

150115120125110130125140150135145155150180180160165175195



6969

15129

129

211515241218121830152133151818241827212130212433272724364230

23235232335543343533

11566463335766

1198675

2222222222223233333333

44444444455555556



Heater Listings


200210220225225240240250255260270270280285290300300315315320330335340345360360360375380380390400405405420425435450450

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




446035446035604460354460356044356044603560443560354460603544603544606044604460

262026262226223424323424322622322822303230223832382232343826363826383826402640

9.59.5

18-3/89.59.5

18-3/89.59.59.5

18-3/89.59.5

18-3/89.5

18-3/818-3/8

9.518-3/8

9.518-3/8

9.518-3/818-3/8

9.518-3/818-3/8

9.59.5

18-3/818-3/8

9.518-3/818-3/8

9.59.5

18-3/89.5

18-3/89.5

8590

12585

100125100105105150105105150115135150120135130150130135175135175135135145175155150175155160160155165155165

185190230200205240215225230270245240285255270300270285285315295300340310355315320335370340350385360360375375390390400



274233304536483354393654426039456042634866455472544872755751816054818457906090

97

1110568

1197

1297

10135

101478

11159

129

16121319179

10189

1419152015

6666677777778888888999

99

101010101010101111111111111212


Heater Listings


750 F Maximum Outlet Air TemperatureLow Velocity Heater

Mounting Hole Details Mounting hole patterns depend on H dimensions. Mounting holes are 9/32 diameter, centered 3/8 from the outside edge of the plate.

6121824303642485460

Dimensions(Inches)

No. OfCircuits

No. OfElements

CatalogNumberCHW

KWWeight(Lbs.)



20-3/820-3/820-3/820-3/820-3/820-3/820-3/820-3/820-3/820-3/8

468

10121416182022

8-11/168-11/168-11/168-11/168-11/168-11/168-11/168-11/168-11/168-11/16

15253545506570809095

HX-164N-901-701UHX-164N-902-701UHX-164N-903-701UHX-164N-904-701UHX-164N-905-701UHX-164N-906-701UHX-164N-907-701UHX-164N-908-701UHX-164N-909-701UHX-164N-910-701U

369

129

1815181818

1111111111

Heater Listings



Mtg. Hole Centers Q

4 6 8 10 12 14 16 18 20 22 1 1 2 3 3 3 3 3 3 3 2.5 3.5 3 2.75 3.25 3.75 4.25 4.75 5.25 5.75

Tubular

KNOCKOUTS ONALL SIDES

AIRFLOW DIRECTION


H

W

C

6

AIRFLOW DIRECTION

K

Q

K

C+2

H+2

P x Q

Mounting Hole Details Mounting hole patterns depend on heater C and H dimensions. Mounting holes are 9/32 diameter, cen-tered 3/8 from the outside edge of the plate.

Heater Listings


Heaters are rated at 480 volts, 3 phase.All 1200 F heaters come with 4 of insulation below flange.* On this item the C dimension is 14 inches for open coil.


510101215152020242530303035

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




20-3/820-3/8

5635

20-3/844

20-3/85635

20-3/820-3/8

4456

20-3/8

464686

1048

121486

16

9.59.5*9.5*9.59.5*9.59.5*9.59.59.5*9.59.59.59.5*

-203530203025-

352530404030

2530253040355055506065555080

HX-164N-101-101UHX-164N-102-101UHX-164N-103-101UHX-164N-104-101UHX-164N-105-101UHX-164N-106-101UHX-164N-107-101UHX-164N-108-101UHX-164N-109-101UHX-164N-110-101UHX-164N-111-101UHX-164N-112-101UHX-164N-113-101UHX-164N-114-101U

-HX-165N-802-101UHX-165N-803-101UHX-165N-804-101UHX-165N-805-101UHX-165N-806-101UHX-165N-807-101U

-HX-165N-809-101UHX-165N-810-101UHX-165N-811-101UHX-165N-812-101UHX-165N-813-101UHX-165N-814-101U

3333636669969

12

11111111111111

-111111-111111

Open Coil

4 INSULATION

H

W

C

6

Heater Depth CNo. of Spaces R

Mtg. Hole Centers KHeater Height HNo. of Spaces P

Mtg. Hole Centers Q

9.5 14 18.38 2 3 4 3.5 3.88 3.88 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 1 1 2 3 3 3 3 3 3 3 3 5 5 5 5 7 7 7 7 7 2.5 3.5 3 2.75 3.25 3.75 4.25 4.75 5.25 5.75 5.75 4.5 5.25 4.88 4.88 4.38 4.88 4.88 5.38 5.25

K

Q

K

C+2

H+2

P x Q



38


40404545485050606060607070727580808590909095

100100105108110110120120120130130135140150155160165170170180

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




20-3/856

20-3/84435

20-3/856

20-3/8354456

20-3/8563544

20-3/85635

20-3/8445635

20-3/8564435

20-3/8563544565635445656355644355635

188

201418228

2622181026102222341222382214224214222642162622181834262022382234382442

9.5*9.5*9.59.59.59.59.5*9.59.59.59.59.5*9.5*9.59.59.59.59.59.59.59.59.59.59.5*9.59.59.5*9.59.59.59.59.59.59.59.59.59.59.5*9.59.5

9.5

3550405555405045656555455565805565656080706565708075657575808585909090

100100100110100105110

8565958095

10575

12511510590

135100125130160115140180140130150200140155170210155180170170180210195195205245220240255230275

HX-164N-116-101UHX-164N-117-101UHX-164N-118-101UHX-164N-119-101UHX-164N-120-101UHX-164N-121-101UHX-164N-122-101UHX-164N-123-101UHX-164N-124-101UHX-164N-125-101UHX-164N-126-101UHX-164N-127-101UHX-164N-128-101UHX-164N-129-101UHX-164N-130-101UHX-164N-131-101UHX-164N-132-101UHX-164N-133-101UHX-164N-134-101UHX-164N-135-101UHX-164N-136-101UHX-164N-137-101UHX-164N-138-101UHX-164N-139-101UHX-164N-140-101UHX-164N-141-101UHX-164N-142-101UHX-164N-143-101UHX-164N-144-101UHX-164N-145-101UHX-164N-146-101UHX-164N-147-101UHX-164N-148-101UHX-164N-149-101UHX-164N-150-101UHX-164N-151-101UHX-164N-152-101UHX-164N-153-101UHX-164N-154-101UHX-164N-155-101UHX-164N-156-101UHX-164N-157-101U


1212159

1215151815121824241815242424271827243030242733333024244236274245424836425445

22532552522442544433345543

11115447437578

6765

222222222222223333333333333444444444455555


18-3/8

Heater Listings



180190190195200205210210215220225230230240240240250250255260265270270275280285290290300300300315315325330335345360375390405420

Dimensions(Inches)

Weight(Lbs.)

No. OfCircuits

No. OfCircuits

No. OfElements

CatalogNumber

CatalogNumberCHW

KWWeight(Lbs.)




565635445635445635564435563544565635445635445635564435563544563544354435444444444444

242642382826383026304226322642323432263632263832382632403826403832383238323238383838

9.59.59.59.59.5

18-3/89.59.5

18-3/89.59.5

18-3/89.5

18-3/89.59.59.5

18-3/818-3/8

9.518-3/818-3/8

9.518-3/8

9.518-3/818-3/8

9.518-3/818-3/8

9.518-3/818-3/818-3/818-3/818-3/818-3/818-3/818-3/818-3/818-3/818-3/8

105110110120120135125125135125135130130135135135140155165145155165155155155165155160180165160180195180195180195195225225225225

240255290280270310295285325295315335310345330320335380355350395370365405375385415390450400400465435475450485480480515530545560



546048426054426354664560726048728163547866548172846072908160908163816684727278788484

558756776

119565869797

11998758

109

1010979

117

12

1213131414

5555666666666777777777777888888889999

1010101111


Control PanelsControl Panels


Amps Number OfCircuitsAmps Per

CircuitMaximum KW Approximate Dimensions (Inches)

Height Width Depth

EstimatedWeight(Lbs.)

4896

144192240288336384

432* 480* 528* 576* 624* 672* 720* 768* 816* 864* 912* 960*

123456789

1011121314151617181920

4848484848484848484848484848484848484848

1939597999

119139159179199219239259279299319339359379399

3979

119159199239279319359399438478518558598638678718758798

85105160175260265320330585600680685800805815930945950960965

2430364248486060606060607272727272727272

2424303036363636484860606060607272727272

88888888

121212121212121212121212

240V/3PH 480V/3PH

*These panels have double doors and 12 high floor stands.

Heatrex can provide a control system for any electric process air heating application. Our experienced engineering staff can design control systems ranging from ON/OFF to full SCR with PID logic. Optional features include ramp/soak, computer inter-face capability and various control schemes as required.

Heatrex offers two standard control panel designs: Full SCR PID control and ON/OFF contactor control. All components are factory mounted and wired in compliance with the National Electrical Code.

These charts provide a sample of standard control panel designs. Custom control panels, designed specifically for your application, are available.

A Vernier control panel can also be supplied. Vernier control utilizes contactors, one SCR controller, and a microprocessor-based sequencer. The sequencer controls the staging of the contactors and the SCR controller. The SCR controller serves to fill in the gaps between the step-controlled stages. Vernier control is not quite as accurate as full SCR control, but more accurate than contactor (step) control.

Contactor Control PanelsThis contactor-based system with ON/OFF process temperature control is recommended for less demanding applications. Systems with two or more heating stages utilize an electronic sequenc-er (step controller), driven by an analog output PID tempera-ture controller to minimize the amount of load cycling while providing good outlet temperature control.

Standard Features: Microprocessor-based sequencer (for panels

with two or more heating stages) Indicating PID temperature controller (adjustable process

temperature with thermocouple input) NEMA 12 painted steel enclosure, wall mount unless

otherwise noted Overtemperature controller (adjustable temperature limit

with thermocouple input) Door interlock disconnect switch Manual reset pushbutton with built-in pilot light (red) for

visual OVERTEMPERATURE alarm Selector switch ON/OFF with built-in pilot light (green) for

POWER ON indication Control power transformer Disconnecting magnetic contactors Circuit fusing

Control Panels

41

A full SCR control system with PID temperature control is recommended for industrial heating applications which must accommodate material flow changes and provide the highest degree of accuracy for outlet temperature control.

Standard Features: PID self-tuning temperature controller (adjustable process

temperature, with thermocouple input) Three-phase, zero cross-fired, SCR power controllers NEMA 12 painted steel enclosure, wall mount unless

otherwise noted

Overtemperature controller (adjustable temperature limit with thermocouple input)

Door interlock disconnect switch Manual reset pushbutton with built-in pilot light (red) for

visual OVERTEMPERATURE alarm Selector switch ON/OFF with built-in pilot light (green) for

POWER ON indication Control power transformer Safety contactors Circuit fusing Ventilating fan and filter when required

SCR Control Panels

Amps Number OfCircuitsAmps Per

CircuitMaximum KW Approximate Dimensions (Inches)

Height Width Depth

EstimatedWeight(Lbs.)

487096

140144210192280240350

295 425* 590* 850*

1122334455

69

1218

48704870487048704870

48474847

19293958598779

11699

145

119175239351

395879

116119174159232199290

239351478703

95115125205195310225385320415

405660750

1090

24303042364842604860

60606072

24**24**24**30**30**36**30**36**36**36**

36486072

8888888888

16161616

240V/3PH 480V/3PH

*These panels have double doors and 12 high floor stands.**Additional 9 clearance required for externally mounted heat sinks which may be mounted on one or both sides of the enclosure for proper convection cooling.

SCR panels with externally mounted heat sinks

SCR panels with internally mounted heat sinks, fan and filter

SCR Power Controllers modulate the entire heater lo

process duct heaters - custom tubular heating elements ... duct...

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