Lincoln Impringer Conveyor Oven 1200 - Manual (Page 49)

Impinger I -–1000 Series Service Manual - International 49
Temperature Control
Check for 120 VAC across L1 and L2 on
temperature control board. If no voltage is present,
retrace wiring back to power supply. Turn the
temperature adjustment knob to the maximum
temperature position and check for 120 VAC at the
load terminal to neutral. If 120 VAC is not present,
proceed as follows: If 120 VAC is present and unit
is not heating, see "Solenoid Valve."
Thermocouple Probe Remove thermocouple leads from the temperature
control board and measure the millivolt output of
these leads. Refer to chart on page 59 for proper
readings. If the thermocouple probe checks good,
then the problem is usually with the temperature
control board.
Solenoid Valve If output voltage is present at temperature control
board, check for voltage at solenoid valve. If
voltage is present, listen for valve to open and
close. Also check for opens, shorts in coil. Replace
as needed.
Temperature Control Check for 120 VAC across L1 and L2 on
temperature control board. If no voltage is present,
retrace wiring back to power supply. Turn the
temperature adjustment knob to the maximum
temperature position and check for 220 VAC at the
load terminal to neutral. If 220 VAC is not present,
proceed as follows: If 220 VAC is present, and unit
is not heating, see "Flame Monitor". Check for 220
VAC at terminal "COM" on temperature control
board. If no voltage is present, trace wiring back to
ignition control.
Thermocouple Probe Remove thermocouple leads from the temperature
control board and measure the millivolt output of
these leads. Refer to chart on page 59 for proper
readings. If the thermocouple probe checks good,
replace temperature control.
Flame Monitor Check for 220 VAC at terminal #1. If no voltage is
present, trace wiring back to temperature control.
Check for 220 VAC output at terminal #8. NOTE:
There is a delay of up to 2 seconds for 220 VAC
output at terminal #8. If there is no voltage output
at terminal #8, check the reset button. Replace
control as needed.
Relay, Main Burner Check for 220 VAC at relay coil, if no voltage is
present, trace wiring back to flame monitor. Check
for 120 VAC to relay contacts. If no voltage is
present, trace wiring back to power supply. Check
to ensure contacts are closing. Replace relay as
needed.
Indicator light is on,
but no main flame
(1033-1034)
Valve, Temperature
Regulation Check for 120 VAC at valve, if no voltage is
present, trace wiring back to relay. If voltage is
present, listen for valve to open and close. Check
for opens or shorts in coil. Replace as needed.