User Guide

User Guide

Muffle Furnace 1100 deg C

OV250

Impact Test Equipment Ltd www.impact-test.co.uk & www.impact-test.com

Impact Test Equipment Ltd. Building 21 Stevenston Ind. Est.

Stevenston Ayrshire

KA20 3LR

T: 01294 602626 F: 01294 461168

E: sales@impact-test.co.uk

Test Equipment Web Site www.impact-test.co.uk

Test Sieves & Accessories Web Site

www.impact-test.com

1. FUNCTION The laboratory furnace is intended for analysis of various materials and for different kinds of thermal treatment (see requirement of point 2) at a temperature o f up to 1100°C. 2. HAZARDS For the furnace mains connection, use only an earthed socket. Operation of the oven without a reliable earth connection is forbidden. Never operate the oven with the enclosure removed. Depending on the furnace temperature and operating time, there is a risk of burning when touching the furnace housing in the door area and during loading and unloading with unprotected limbs. Suitable protection must be worn when using the furnace (e.g. gloves). Do not place unknown materials in the furnace! Combustible or explosive materials, or t h o s e t h a t may release combustible or explosive substance during heat treatment, must not be processed in the furnace. Substances which release a quantity of oxygen during their decomposition may cause a gas/oxygen mixture that can be explosive. Only carry out repairs with the furnace disconnected from the mains electricity supply.

Marks:

Alternating current

Earthing

Danger of Electric Shock

3. SUPPLY

Furnace OV250 1 Bottom plate, unit 2 Support, unit 4 Fuse, unit 1 Instruction manual 1 Instruction manual of temperature controller 1

4. LAYOUT AND OPERATON The furnace comprises a main frame, housing manufactured from sheet steel, working chamber, control panel (pic.1). Vacuumed fibre chamber is installed in the housing. Heating elements are vacuumed in the fibre around the working chamber. Door with thermal insulation material is mounted in the front section of the frame. The working chamber of the furnace consists of the heating element and a door seal. Put the charge on the bottom plate in the chamber. Charge imposing great specific pressure and wear-out effect upon the chamber bottom (metal blanks, ceramic articles, etc.) is located on a bottom plate additionally provided in the chamber. The furnace has a 230V 50Hz power supply. Temperature control and adjustment is effected by an electronic controller operating in combination with a thermoelectric converter mounted in the chamber. Electric diagram is attached. 5. USAGE INSTRUCTIONS The furnace is designed for indoor use and the following environmental conditions must be satisfied:

• Firm horizontal surface (±1mm on 1 metre), rigid and flameproof. • Temperature range plus 5° C to 35° C. • Maximum relative humidity 80% at temperature plus 25 °C • Explosion – proof environment, free of a considerable amount of

conducting dust, water vapour and corrosive gases. • Nominal temperature range must not be exceeded. • The supply network voltage fluctuations not to exceed ±10% of the nominal voltage • During the usage cracks could appear, which have no influence to the furnace

functionality. 6. INSTALLATION Unpack the furnace, remove the transport fixtures from the inner compartment and remove any dust. Mount dismounted components: attach supports, place a bottom plate. The voltage quoted on the rating plate (rated voltage) must correspond with the nominal supply network voltage. Insert a plug into the earthed socket outlet.

7. BEFORE USE Before the first heating cycle with load or after a long period of non usage the moisture must be expelled from the furnace. To expel moisture and ensure a long lifetime o f heating elements we recommend a temperature schedule according to following recommendations with a closed door and an empty chamber:

1. raise temperature to 150-200°C hold for 2-3 hours; 2. raise temperature to 500°C hold for 2-3 hours; 3. raise temperature up to nominal temperature and hold for 1-2 hours; 4. switch off the furnace and allow to cool down.

During this process, smoke may appear. This has no influence on the furnace functionality. After this drying process the furnace is fully functional.

8. OPERATION Open the door and place samples on the bottom plate. Do not position the samples too close the walls (at least 1/10 of the chamber working dimensions should be left unloaded). Close the door. Switch supply network switch / circuit breaker into the ON position. Set the desirable operating conditions by following the temperature controller instructions at the end of this document. The furnace should not be switched ON for longer than needed for the heating cycle. 9. MAINTENANCE Furnace should be disconnected from mains. Door adjustment: Open the door and loosen the door hinge fastening screws to make adjustments. Electrical connections: At least once e v e r y six months the user must visually check wiring and electrical connections. If necessary the contact screws must be tightened. Fuse replacement: To replace the fuse: - press fuse holder convex, turn it counter-clockwise against clock direction and take out fuse holder convex with fuse; - replace the burned fuse with a new one; - repeat the procedure in reverse. 10. STORAGE The furnace should be stored in indoor premises and packed in a box, with the following conditions satisfied: Temperature range 5° C - 35° C; In an environment saturated with sulphur gas and salt chloride of a concentration 0,13mg/m3 and 0,3 mg/m2 per day respectively; Maximum relative humidity could be 80% at the temperature plus 25°. 11. TRANSPORTATION The furnace must be delivered only on covered means of transportation at an ambient temperature ranging from minus 50° C to plus 50° C.

13. TECHNICAL DATA

Rated power, kW 1.8 Rated supply voltage, V 230 Rated frequency, Hz 50 Number of phases 1 Rated temperature, °C 1100 Working chamber surroundings air Heat – up time (without charge), min 50 Furnace temperature stability at rated temperature in thermal steady state without charge not more then ±°C 2 Furnace temperature uniformity at rated temperature in thermal steady state Without charge not more then ±°C 10 Furnace working chamber dimensions: width, mm 200 depth, mm 300 height, mm 133 Furnace outside dimensions:

width, mm 440 depth, mm 560 height, mm 510

Weight net not more than, kg 28

All thumbnail specifications are indicated only for the basic version.

In the interest of efficiency & improvements small design amendments may be introduced without notice in this publication.

14. FAULT FINDING

Failure Fault Remedy The furnace will not turn on.

There is no rated power supply voltage The fuse is burnt out

Check the power supply

Change the fuse The furnace will not heat.

Thermocouple is mechanically damaged The temperature controller is not switched on Heating element is damaged

Change the thermocouple Switch on temperature controller

Replace heating element

Heating time is longer than determined

Low voltage of the power supply Door’s close is not hermetic Solid-state relay is damaged

Check the voltage of power supply Regulate tightness of door’s closure Change the Solid-state relay

There is no exact automatic temperature regulation.

Temperature’s regulator is not regularised

Switch on automatic selection of parameter (look to temp. regulation instruction for users) select the programme and switch on it’s performance

pic 1

1. Control panel 2. Chamber 3. Housing 4. Thermocouple 5. Support 6. Door

ELECTRIC DIAGRAM

component Qty Article identification Type

F1, F2 2 Fuse, 12,5A, M;

S,S**4 1 Switch R595KMET2F P 1 Temperature controller E5CK-T

(E5CN; 33208; 3216)

SR 1 Solid-state relay G3PB225BVD 1224DC

S1 1 Switch 10A, 250V

D2D-3104

TC 1 Thermocouple, “K” TC-Y1 (K)

E 1 Heating element

T**3 1 Timer MIL72E/1digi20 B**5 1 Bell

М1**4 1 Ventilator DP200A

This operating guide provides details for the basic operation of the Omron E5CC temperature controller in your furnace or oven. The controller’s display shows the temperature in the chamber, at the top and Set-point temperature, at the bottom. To change the Set-point use the up or down arrows. The PF key can be used to select the digit being changed for faster adjustment. The controller can be put into Stop mode, where the Set-point is remembered but the heating control is off, or Run mode, for normal operation. To change the mode, press the Mode key (the circular arrow) and use the up and down arrows. The controller has been configured at the factory for optimum control terms. In some applications it may be beneficial to perform an Autotune, but if the unit is performing satisfactory, there is no need perform an Autotune or change any other settings. The following pages from the full Omron User’s Manual provide instructions for unprotecting the controller’s hidden settings and instructions on how to perform an Autotune. However, incorrect changing of some settings that are available in this mode can result in poor performance or at worst could be potentially dangerous. Refer to the Omron E5CC Instruction Manual provided in conjunction with these instructions. To unprotect the Operation Level, move to the Protect Level and change Operation / Adjustment Protect to ‘0’. Then move to the Adjustment Level and refer to the Autotune instructions in the following pages. Once finished, return to the Protect Level and return Operation / Adjustment Protect to its original setting.

Adjustment Level

Moving from the Operation Level to the Adjustment Level

1 Press the O Key for less than 1 second in the OperationLevel.

Operation Level

The display will change from the Operation Level to the AdjustmentLevel.* l.adj will be displayed only once when you move to the Adjustment

Level.

Adjustment Level

Moving from the Adjustment Level to the Operation Level

1 Press the O Key for less than 1 second in the AdjustmentLevel.

Adjustment Level

The display will change from the Adjustment Level to the OperationLevel.

Operation Level

Protect Level

Moving from the Operation Level to the Protect Level

1 Press the O and M Keys simultaneously for at least 3seconds* in the Operation Level.The No. 1 display will flash when the keys are pressed for 1 s orlonger.* The key pressing time can be changed in the Move to Protect Level

Time parameter in the Advanced Function Setting Level.

Operation Level

The display will change to the Protect Level. Protect Level

Moving from the Protect Level to the Operation Level

1 Press the O and M Keys simultaneously for at least 1 secondin the Protect Level.

Protect Level

The display will change from the Protect Level to the OperationLevel.

Operation Level

0

25

l.adj

0.0

ins Process Value Input Shift

0

25 PV/SP

0

25

0

oaptOperation/AdjustmentProtect

0

oapt

0

25 PV/SP

4-9-1 AT (A

uto-tuning)

Determining PID Constants

AT OperationsAT is started when either at-2 (100% AT) or at-1 (40% AT) is specified for the AT Execute/Cancelparameter.The TUNE indicator will light during execution.Only the Communications Writing, RUN/STOP, AT Execution/Cancel, and Program Start parameterscan be changed during AT execution. Other parameters cannot be changed.

AT Calculated GainThe AT Calculated Gain parameter sets the gain for when PID values are calculated using AT. Whenemphasizing response, decrease the set value. When emphasizing stability, increase the set value.

AT HysteresisThe AT Hysteresis parameter sets the hysteresis when switching ON and OFF for the limit cycleoperation during auto-tuning.

AT (Auto-tuning)

• When AT is executed, the optimum PID constants for the set point at that time are set automatically. A method (called the limit cycle method) for forcibly changing the manipulated variable and finding the characteristics of the control object is employed.

• Either 40% AT or 100% AT can be selected depending on the width of MV variation in the limit cycle. In the AT Execute/Cancel parameter, specify at-2 (100% AT) or at-1 (40% AT). To cancel AT, specify off (AT cancel).

• Only 100% AT can be executed for heating and cooling control.• If the Heating/Cooling Tuning Method parameter is set to any value other than

0 (same as heating control), the PID constants are set automatically for both heating control and cooling control.

• AT cannot be executed when control has stopped or during ON/OFF control.• The results of autotuning are saved in the following parameters in the

Adjustment Level: Proportional Band (P), Integral Time (I), Derivative Time (D), Proportional Band (Cooling) (C-P), Integral Time (Cooling) (C-I), and Derivative Time (Cooling) (C-D).

Adjustment Level

at

8.0

p

233

i

40

d

Proportional Band (Cooling)

8.0

c-p

Integral Time (Cooling)

233

c-i

Derivative Time (Cooling)

40

c-d

Proportional Band

Integral Time

Derivative Time

Limit Cycle MV AmplitudeThe Limit Cycle MV Amplitude parameter sets the MV amplitude for limit cycle operation duringauto-tuning.* This setting is disabled for 100% AT.

40% AT• The width of MV variation in the limit cycle can be changed in the Limit Cycle MV Amplitude

parameter, but the AT execution time may be longer than for 100% AT. The limit cycle timing variesaccording to whether the deviation (DV) at the start of auto-tuning execution is less than 10% FS.

100% AT• Operation will be as shown in the following diagram, regardless of the deviation (DV) at the start of

AT execution. To shorten the AT execution time, select 100% AT.

This procedure executes 40%AT.

Operating Procedure

1 Press the M Key several times in the Adjustment Level to dis-play at (AT Execute/Cancel).

Adjustment Level

2 Press the U or D Key to select at-1 (40% AT execute).* The TUNE indicator will light during autotuning.

3 When AT ends, the AT Execute/Cancel parameter is set to OFF. Adjustment Level

SP

PV

AT started AT ended

Time

Limit Cycle MV Amplitude 40%

Deviation ≥ 10% FS

Deviation: 10% FS

Time

Deviation < 10% FS

SP

PV

AT started AT ended

Limit Cycle MV Amplitude 40%

Deviation: 10% FS

* The Limit Cycle MV Amplitude parameter is disabled.

SP

PV

AT started AT ended

Time

Limit Cycle MV Amplitude 100%

off

at AT Execute/ Cancel

at-1

at

off

at AT Execute/ Cancel