Service manual

31
Service Manual for Flexible Batch Broiler Units
Testing the Transformers
There are two 24-volt Step-Down Transformers in the
broiler. One supplies power to the Control Board, the
other provides power to the Ignition Modules. Either
a voltage or a resistance check can be used to test the
Transformers.
Voltage Test
1. Make sure the broiler is turned off.
2. Remove the Lower Control Side Service Panel.
Refer to the COVERS and PANELS section of the
manual.
3. Disconnect the secondary winding.
4. Turn the broiler on.
5. Using a VOM, test the voltage output across the
secondary winding. Voltage should be 24VAC.
Resistance Check
WARNING
DISCONNECT THE ELECTRICAL POWER
TO THE BROILER AND FOLLOW
LOCKOUT / TAGOUT PROCEDURES.
1. Turn the broiler off.
2. Remove the Lower Control Side Service Panel.
Refer to the COVERS and PANELS section of the
manual.
3. Tag and disconnect the wires of the Transformer
to be tested.
4. Measure the resistance across the primary. Primary
Resistance = 21.8Ω ±10%.
5. Measure resistance across secondary.
6. Secondary Resistance = 0.8Ω ±10%.
Lower Ignition Module Testing
When the Cook Chamber Temperature Probe calls for
heat, the Control Board will send 24VAC to terminals
TH and GND on the Lower Ignition Module. The Lower
Ignition Module rst performs a diagnostic check. After
the diagnostic, the Lower Ignition Module is activated.
• 24VAC is applied across terminal V1 opening the
Lower Combo Gas Valve.
• High voltage spark is generated at terminal HV.
• When the Flame Sensor detects a current ow of
not less than 0.7uA, the Igniter stops sparking.
The Lower Ignition Module performs a self-
diagnostic check. It is equipped with an LED that has
three states, indicating the type of diagnostic failure:
1. Steady On: Indicates internal failure of the module.
The module must be replaced.
2. Two Flashes of the LED: Indicates the burner is
lit but no call for heat exists.
3. Three Flashes of the LED: Indicates ignition lockout
has occurred.
Upper Ignition Module
The Upper Ignition Module works in the same manner
as the Lower Ignition Module, but it has two Igniters and
Flame Sensors. The Control Board will send 24VAC to
terminals W and GND on the Upper Ignition Module.
• 24VAC is applied to terminal W and Ground, which
opens the Upper Combo Gas Valve.
• High voltage spark is generated at terminals HV1
and HV2.
• When the Flame Sensors detect a current ow of
not less than 0.7uA, the Igniters stop sparking.
The Upper Ignition Module performs a self-diagnostic.
Upper Ignition Module Diagnostic Indicators:
1. Steady On: Indicates an internal control failure.
2. Two Flashes: Indicates the burner is lit but no call
for heat exists.
3. Three Flashes: Indicates ignition lockout has
occurred.
Checking the Flame Sensors
Typically, an Ignition Module Lockout is caused by
dirty Flame Sensors.
Here are some Flame Sensor tips: