Trane A4AC3018A1000A Installer's Manual page 26

Compressor won't run
Contactor is closed
Check for high
voltage to contactor
Is high voltage present
at T1 and T2 ?
Check power
supply from
disconnect and/or
breaker panel.
26
TROUBLESHOOTING
Check for open IOL
YES
(Internal Overload)
Check resistance of
C to S and C to R
NO
Does the
resistance check
show an open
circuit from C to S
or C to R?
Check for open
windings.
Does a resistance check
show an open circuit
between R and S?
Check for locked
rotor
Is voltage present
at C to S and C
to R with locked
rotor amps on C?
Check wiring to
compressor
C, S and R
Allow compressor
YES
time to cool and
re-test
NO
YES
Replace the
compressor
NO
Check Start-
YES
Capacitor and
Relay (if present)
and Run Capacitor
NO
Do the start
components and
run capacitor
check good?
Replace start
components and/
or run capacitor
YES
Replace the
compressor
NO
88-A4AC3001-1C-EN