Despatch LAC2-12-7 - Manual (Page 38)

M AINTENANCE 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.