TurboChef 3240 - F7: RTD Fault; High Limit Tripped

38 TROUBLESHOOTING
Troubleshooting:
F8: HIGH LIMIT TRIPPED (High Limit Trip)
Is the high limit thermostat
tripped (page 21)?
Reset and determine why it
tripped - over temp, blower
failure, etc.
Check if the high limit probe
or RTD is damaged or defec-
tive, replace if needed (page
A-8).
Ensure that the minimum gas
pressure is correctly set, reset
if needed (page 3).
NO
YES
Troubleshooting:
F7: RTD FAULT (RTD Failure)
Open the right end bell.
Is the RTD damaged or
defective (page 23)?
Is the RTD
connected
properly to the
I/O control
board
(page 45)?
Replace the I/O
control board
(page A-8).
NO
Correct wiring
(page 45).
Replace the RTD
(page A-8).
YES
NO
NO
YES
YES
Replace RTD
(page A-8).
Are all the contacts
closed on the high
limit thermostat?
Is the wiring
correct
(page 45)?
NO
YES
Replace the high
limit thermostat
(page A-14).
NO
YES
Correct wiring
(page 45).
Replace the I/O
control board
(page A-8).
Is the RTD open? Using an ohmmeter,
measure at the control board (pages 45-
47). RTD should measure approxi-
mately 4-5 W. (See page 24 for
ohm/temperature chart.)