Lincoln Impinger 1002, Service Manual

Page: 46 / 112

Impinger I -–1000 Series Service Manual - International 46
TROUBLESHOOTING / GAS OVENS 1033, 1034, 1046, 1047
SYMPTOM POSSIBLE CAUSE EVALUATION
Incoming Power Supply Check breaker/reset if required. Call Power
Company if needed. In these ovens, there is a
control circuit step-down transformer. This
transformer steps down supply voltage to 120 VAC.
If main fan will not run, the secondary of this
transformer must be checked for 120 VAC output.
Check specific oven model schematic for circuit
location.
Transformer Fuse Check and/or replace.
Fuseholder Check and/or replace.
Fan Switch Check continuity between switch terminals.
Oven Start Relay Check for 120 VAC to the relay coil. If voltage is not
present, trace wiring back to the fan switch. If
voltage is present, check to insure contacts are
closing.
20 Minute Time Delay Check for 120 VAC at terminal #1 to neutral on the
20-minute timer. If no voltage is present, trace
wiring back to the power supply. If voltage is
present at terminal #1, check for 120 VAC at
terminal #2 to neutral. If no voltage is present, and
the oven start relay is closed, replace the 20-
minute timer.
Oven Fan Relay Check for 120 VAC to coil of the oven fan relay. If
no voltage is present, trace wiring back to terminal
#2 of the 20-minute timer. Check for 120 VAC at
terminals #2 and 6 of the relay, if no voltage is
present, trace wiring back to the power supply. If
voltage is present at the relay coil, check to insure
the contacts are closing.
Fan Fuse Check, replace if necessary.
Fuseholder Check, replace if necessary.
Capacitor Check for opens, shorts, or grounds.
Oven fan will not run
Motor Check for opens, shorts, or grounds. WITH
POWER OFF: turn the fan blade to check for
locked rotor.
20 Minute Time Delay Check for 120 VAC at terminal #2 to neutral while
oven is "on". Turn off the main fan switch, 120 VAC
should continue to be present for 20 minutes. If
voltage is not present for approx. 20 minutes,
replace the timer.
No main fan cool down
Oven Fan Relay Check if relay is operating and that the contacts
remain closed during the 20 minute cool down.
Oven Start Relay Contacts should open when main fan switch is
turned off.
20 Minute Time Delay 120 VAC at terminal #2 should discontinue
approximately 20 minutes after main fan is
switched off. If the oven start relay contacts are
open, and the voltage continues at terminal #2 of
the 20 minute timer, replace the timer.
Main fan runs after 20
minute cool down
Oven Fan Relay Check to insure that the contacts are opening after
the coil is de-energized.
No control box cooling Fan Switch Oven Start
Relay20 Minute Time Delay
Oven Fan Relay Cooling
Fans
(SEE MAIN FAN WILL NOT RUN) 120 VAC should
now be at this motor. If voltage is present, check
motor for shorts, opens, or grounds. WITH POWER
OFF: check for locked rotor.