TurboChef 3240 Service Manual page 48

2 8 O V E N S YS T E M S
1. Shut off the gas supply.
2. Disconnect the wire spark cable from the
stud terminal of the ignition module. This
will isolate the burner spark rod from the
ignition module.
3. Using a different wire spark cable (ensure
that the cable is not damaged in any way),
attach one end to the stud terminal of the
ignition module.
4. Touch the other end of the ignition cable to
the ground terminal of the ignition module
(DO NOT remove the existing ground lead
from the ignition module).
5. Apply power to the ignition module.
6. Before the ignition module goes into a
safety lockout (6 seconds), slowly move the
end away from the ground terminal. A
spark length of 1/8" (3 mm) or more
indicates good ignition voltage. If there is
no arc or the maximum spark length is less
than 1/8" (3 mm), and the input voltage to
the ignition module is 20-25 VAC, the
ignition module is damaged or defective
and must be replaced (page A-14).
Domestic International
25 VAC TH/W
25 V V2 GND
Alarm Not Used
Valve V1/PV1
Valve V2 GND
Ground V2 GND
Figure 34: Ignition Module Terminal Differences
Testing Procedure for Testing Flame Rectification
Figure 35
1. Ensure the oven is in the off or cooling down
mode (page 10).
2. Remove the flame signal ground wire from
the ignition module.
3. Connect a DC multipurpose meter that is
able to read micro amps (uA) in series with
the flame signal ground wire.
-Connect the red (+) meter lead to the free
-end of the flame signal ground wire.
-Connect the black (-) meter lead to the quick
-connect flame signal ground wire terminal
-on the ignition module.
4. From the off or cooling down mode, select a
cooking profile to operate the oven burner.
5. The reading must be above 1.5 DC uA and it
must be steady.
The oven control system uses basic flame
rectification to verify if a flame is present. The
micro amps must be greater than 1.5 DC uA. If
the reading is below 1.5 DC uA or is not steady,
remove the burner assembly and investigate the
cause. Look for a loose ignition/sensor wire, or
defective sensor assembly. Follow the
troubleshooting steps outlined on pages 34-35.
ALARM
VALVE
VALVE
GND
Figure 35: Measuring Microamps
MULTIPURPOSE METER
RED (+)
BLACK (-)