Despatch RFD1-42 -2E with Protocol 3 - Manual (Page 29)

RFD1-42-2E Oven Owner’s Manual T ROUBLESHOOTING
Version 1 29
Copyright © 2012 by Despatch Industries.
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Difficulty Probable Cause Suggested Remedy
Erratic temp. or
inaccurate temp Protocol 3 controller
malfunction
Improper tuning parameters
Protocol 3 controller
miscalibration
High Limit setting
Improper offset Replace Protocol 3 controller.
Check tuning parameters.
Recalibrate Protocol 3 controller (see Protocol
3 Controller Owner’s Manual for further
instruction).
High Limit should be 10-25ºC higher than
setpoint.
Check zone calibration.
Excess surface or
door temp. Door seal deterioration Replace door seal.
Improper airflow Fan motor failure
Fan wheel seated too low on
fan shaft
Unbalanced fan wheel Replace fan motor.
Adjust fan wheel for 3/16" clearance between
wheel and inlet ring.
Replace fan wheel.
Excessive
vibration Dirty fan wheel
Unbalanced fan wheel Clean fan.
Replace fan wheel.
Oven will not
control at setpoint High Limit set too low
Protocol 3 controller
malfunction
SSR malfunction
Air friction of recirculation fan Set the High Limit higher.
Replace Protocol 3 controller.
Replace SSR and/or check control output
voltage.
Open exhaust air vent. Unit will not control
below minimum operating temperature with
vent closed.
Heater does not
shut down until
temp. reaches the
High Limit setting Protocol 3 controller
malfunction
SSR malfunction Replace Protocol 3 controller.
Replace SSR.