Despatch RAD Series - Manual (Page 34)

T ROUBLESHOOTING RAD Oven Series Owner ’s Manual
34 Version 1
Copyright © 2012 by Despatch Industries.
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7.2. Troubleshoot Airflow Conditions
Table 3 lists possible problems and remedies for airflow conditions.
Table 3. Airflow Troubleshooting.
Conditions Actions
A. Non-uniform work
chamber 1. Check to get a lightly positive chamber pressure by closing down
exhaust or opening up fresh air.
a. Review damper instructions (Section 3.2)
b. Adjust optional supply louvers:
i. Open for cold spots
ii. Close for hot spots
c. If necessary, adjust optional return louvers in the same
manner.
2. Check motor for proper operation and direction of rotation.
B. Cold by door 1. See A-1.
2. Check door seals.
3. Open optional supply louvers close to door.
C. Positive pressure in
chamber
1. Close fresh air damper.
2. Open exhaust damper.
3. Refer to Damper Control Section 3.2 for more information.
D. Negative pressure
in chamber
1. Close exhaust damper.
2. Open fresh air damper.
3. Open optional supply louvers slightly.
7.3. Troubleshooting: Error Messages and Alarm
Table 4 lists the more common error messages, the possible problems and remedies.
Table 4. Error Messages and Next Steps.
Alarm Status
Possible Problem Next Step
HI LIMIT LED ON 
Problem with thermocouple

High Limit setpoint has
been exceeded.
Once the problem has corrected, press
RESET.
DEV HOLD LED flashing Oven temperature has not
entered (or dropped out of) the
Auto Hold band and the soak
timer has stopped Program a slower ramp rate or if oven
is not heating check heater circuit.
Top PV displays OPEN Control thermocouple is
disconnected or broken Repair or replace the thermocouple.
HLPV displays OPEN High Limit thermocouple is
disconnected or broken Repair or replace the thermocouple.