Despatch LAD Series WITH PROTOCOL PLUS - Manual (Page 65)

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Troubleshooting
Equipment which operates for long periods of time may develop problems. Below are
possible problems and suggested solutions. If you have a problem not listed and do not
know what to do, contact Despatch Industries at our toll free Help Line 800-473-7373.
Difficulty Probable Cause Suggested Remedy
Failure to heat No power
Burned out heater
Protocol™ malfunction
Loose wire connections
Heater relay failure
Door switch failure
(if installed) Check power source and/or oven and wall fuses.
Replace heater (see warranty.)
Replace controller.
Disconnect power and check connections behind
control panel.
Replace circuit board.
Replace door switch.
Slow heat up Improperly loaded
Low line voltage
Heating element(s) are
burned out
240 volt oven is connected to
a 208V line (LAD1-42 only)
Fan motor failure Reduce load or redistribute load in chamber.
Supply sufficient power and proper connections.
Check for circuit overload.
Replace burned out element (see warranty
statement.)
Raise line voltage to a 240 volt line or modify oven
for 208V operation (consult factory).
Replace fan motor.
Frequent heater
element out Harmful fumes generated by
load
Spillage or splattering of
material on heater elements
Overheating oven Increase vent opening or discontinue process.
Disconnect power and clean oven chamber and
elements.
Check the Hi-limit.
Erratic temp. or
inaccurate temp.
Protocol™ malfunction
Improper tuning parameters
Protocol™ miscalibration
Hi-limit setting
Improper offset Replace Protocol™.
Check tuning parameters.
Recalibrate Protocol™ (see section on Calibration
mode.)
Hi-limit should be 10-25°C higher than setpoint.
Check zone calibration.
Excess surface
or door temp. Door seal deterioration Replace door seal.