Lincoln Foodservice 1600-000-A, Service Manual

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Low Profile – 1600 Series Advantage Digital Service Manual – Domestic 6
Ignition control After 45 seconds of hot surface igniter pre-heat, the ignition
control will switch 24 VAC to the gas control valves. Check for
24 VAC output from the ignition control, across terminals
marked “valve” and “valve gnd”. If no voltage is present, replace
the ignition control.
NOTE: The ignition control contains a safety lockout circuit. If a
flame is not detected within 6 seconds after the gas control
valve is energized, the ignition control will lockout. To reset, turn
the power switch “off”, wait 45 seconds and switch the system
“on” to retry ignition.
Gas control valves Check for 24 VAC supplied to the gas control valves. If voltage
is present, the valves should open. Check for gas pressure at
the pressure tap, located in the gas piping just prior to the
burner. If there is no gas pressure, and the voltage is supplied to
the valves, check piping for obstructions. If there are no
obstructions, replace gas control valves.
Flame will not stay lit Hot surface igniter The ignition control will keep the gas control valves energized
for 6 seconds. At the end of 6 seconds, the hot surface igniter
must sense a flame, or the ignition control will go into lockout.
(The ignition control requires a minimum of 0.8 micro-amps DC)
To check the flame sensing operation, connect a digital
multimeter (capable of measuring DC micro-amps) between the
“GND burner” terminal on ignition control and the ground wire.
NOTE: This is a current measurement and the meter must be
connected in series.
If these readings are not achieved, check bypass orifice for
obstructions, if bypass orifice is clear, replace the hot surface
igniter.
NOTE: The DC micro-amp test must be conducted with the oven
in low flame (bypass) operation. Set the temperature control to
its lowest setting.
Power supply If there is sufficient micro-amp current, but the flame will not stay
lit, check for proper polarity of the 120 VAC power supply.
Ignition control If there is sufficient micro-amp current, and the 120 VAC polarity
is correct, but the flame will not stay lit, replace the ignition
control.
NOTE: check for proper ground connection of the ignition
control.
NOTE: Flame should
be lit at this time
Low flame is on, but no
main flame
Control transformer Check for 120 VAC supply to the primary of the control
transformer. If no voltage is present, trace wiring back to the
oven power relay. If voltage is present, check for 24 VAC at the
transformer secondary. If there is primary voltage but no
secondary voltage, replace control transformer.