Instruction Manual

MAINTENANCE LAC Series Oven Owner’s Manual
38 Version 1
Copyright © 2012 by Despatch Industries.
All rights reserved. No part of the contents of this manual may be reproduced, copied or transmitted in any form or by any
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7. Troubleshooting
7.1. Troubleshooting Symptoms
Table 2 lists symptoms, probably causes and suggested remedies. Table 3 shows how to
troubleshoot the control panel mounted circuit board.
Table 2. Troubleshooting Oven Symptoms.
Symptom
Possible Cause
Next Step
Failure to
heat or
heats to
only 35-50
degrees C
No power
Check power source and/or oven and wall fuses.
Broken or frayed cord
Replace with new cord.
Burned out heater
Replace heater (see Warranty Section 8.1).
Protocol 3 controller
malfunction
Replace controller.
Loose wire connections
Disconnect power and check connections behind control
panel.
Heater relay failure
Replace circuit board.
Door switch failure
Replace door switch.
Slow heat-
up
Improperly loaded
Reduce load or redistribute load in chamber.
Low line voltage
Supply sufficient power and proper connections. Check
for circuit overload.
Heating element(s) are
burned out
Replace burned out element (see Warranty Section
8.1).
240 volt oven is
connected to a 208V line
Raise line voltage to a 240 volt line or modify oven for
208V operation (consult factory).
Fan motor failure
Replace fan motor.
Frequent
heater
element out
Harmful fumes generated
by load
Increase vent opening or discontinue process.
Spillage or splattering of
material on heater
elements
Disconnect power and clean oven chamber and
elements.
Overheating oven
Check the High Limit.
Erratic or
inaccurate
temperature
Protocol 3 controller
malfunction
Replace Protocol 3 controller.
Improper tuning
parameters
Check tuning parameters.
Protocol 3 controller
miscalibration
Recalibrate Protocol 3 controller (See Protocol 3
Owner’s Manual, sections on Calibration).
High Limit setting
High Limit should be 10-25°C higher than setpoint.
Improper offset
Check zone calibration.
Excess
surface or
door
temperature
Door seal deterioration
Replace door seal.
Improper
airflow
Fan motor failure
Replace fan motor.
Fan wheel seated too low
on fan shaft
Adjust fan wheel for 3/16" clearance between wheel and
inlet ring.
Unbalanced fan wheel
Replace fan wheel.
Excessive
vibration
Dirty fan wheel
Clean fan.
Unbalanced fan wheel
Replace fan wheel.