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SYMPTOM
Oven fan will not run
Oven will not heat
6
TROUBLESHOOTING GUIDE
1921
1922
POSSIBLE CAUSE
Incoming power supply
Fuses, 10 Amp, motor and
controls
Fuse holder
Hi-limit thermostat,
Oven cavity
Switch, main power
30 minute time delay relay
Relay, main fan
Transformer, Motor
(MODEL 1922 ONLY)
Circuit breaker(s), 3A.
Main fan motor
Capacitor
Main fan motor
Air pressure switch
208 VAC
240 VAC
EVALUATION
Check circuit breakers. Reset if required. Call power
co. if needed.
Check, replace if necessary.
Check, replace if necessary.
Terminals are normally closed. If open, reset
thermostat and retest. If thermostat will not hold for
maximum oven temperature, and oven is not exceeding
temperature setting, check for proper location of
capillary bulb in its spring holder. If the capillary checks
okay, replace the hi-limit thermostat.
Check continuity between switch terminals. Replace
switch as needed.
Check for supply voltage to 30 minute time delay relay
at terminals #1 and #6. If no voltage is present, trace
wiring back to main power switch. If there is supply
voltage at terminals #1 and #6, check for output voltage
at terminals #2 and #3. If there is incoming voltage but
no output voltage, and the main power switch is on,
replace the 30 minute time delay relay.
Check for supply voltage to relay contacts, if no voltage
is present, trace wiring back to power supply. Check for
supply voltage to the coil of the main fan relay. If no
voltage is present, trace wiring back to the 30 minute
time delay relay. If voltage is present, check to insure
contacts are closing. Replace as needed.
Check for 240 VAC supply to the transformer primary. If
no voltage is present, trace wiring back to relay. If
240VAC is present at transformer primary, check for
208VAC at the transformer secondary. If there is
primary voltage, but no secondary voltage, replace
transformer.
Push and reset circuit breakers. Check for voltage to
the circuit breaker. If no voltage is present, trace wiring
back to the main fan relay. If there is voltage present,
proceed. Check for continuity through the circuit
breaker, if the circuit breaker has been reset and there
is no continuity through the circuit breaker, replace the
circuit breaker.
Check for supply voltage at motor. If no voltage is
present, trace wiring back to circuit breakers.
WITH POWER OFF: Check for opens, shorts or
grounds. Turn fan blade to check for locked rotor.
Check for shorts or grounds.
WARNING: Capacitor has a stored charge, discharge
before testing.
Check for main fan operation. If it is not operating, refer
to "Oven fan will not run".
This normally open switch should close when the main
fan is activated. Refer to the "Removal and installation"
section for proper adjustment. Replace as needed.
60 HZ.
3 PHASE
60 HZ.
3 PHASE
DTF – 1920 Series Service Manual
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