Heater Circuit Troubleshooting - Despatch LCC Series Owner's Manual

C244, 320207, REV B
Difficulty Probable Cause
Excessive Dirty fan wheel
vibration Unbalanced fan wheel
High Limit set too low
Temperature controller
malfunction
SCR malfunction
Oven will not
control at
Air friction of
setpoint
recirculation fan
Airflow switch
malfunction
Heater does Temperature controller
not shut down malfunction
until SCR malfunction
temperature
reaches the
High Limit
setting

8.2. Heater Circuit Troubleshooting

Warning!
The following troubleshooting steps must be performed by a
qualified electrician or electrical technician that has been trained
on electrical safety and personal protection equipment
If oven is not heating, first check status of temperature control heater ON/OUT
indicator light on the left button column of the Protocol 3, Figure 29. Light should
be ON for the oven to heat up.
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LCC_LCD1-16/51 Oven Owner's Manual
Suggested Remedy
Clean fan
Replace fan wheel
Set the High Limit higher.
Replace controller
Replace SCR and/or check control output
voltage.
Open exhaust air vent. Unit will not control
below minimum operating temperature with
vent closed.
Check recirculation and exhaust fan rotation and
pressure switch setting
Replace controller.
Replace SCR