J&M CellarPlus 70-S1/S3, Technical Manual

Page: 16 / 32

Issue: 01.06.2023 Page 13
Appendix
Table 13: Trouble Shooting
FAULT POSSIBLE CAUSE CHECK SOLUTION
COMPRESSOR
Compressor will
not start Power supply Is power switched on? If not - switch on
Phase and neutral present? Check/rectify
Voltage within tolerance? Check/rectify
Compressor contactor not
pulled in (contactor in
outdoor unit) Is there correct voltage to
contactor coil? (Terminals
A1 & A2) If yes - coil faulty. Replace contactor
Is the controller calling for
cooling? (Cooling LED lit) If yes - check for break in control circuit
Is the controller on defrost?
(Defrost LED lit If yes - wait for defrost to finish or
terminate defrost and check operation
Is there an alarm condition
shown on the controller
display? Refer to manual for alarm identification
and resolution
Has a safety switch tripped
out? Check cause and rectify
Compressor contactor
pulled in but compressor
not running Is voltage being switched
across contactor? (Terminals L
& T) If yes - check voltage present at
compressor terminals. If correct -
compressor may have tripped internal
overload or be faulty
If no. Replace faulty contactor
LP switch tripped (on
outdoor unit) Low pressure condition Low refrigerant charge/icing of
evaporator coil/evaporator fan
failure/blockage in piping. Check &
rectify cause
Compressor internal
overload tripped Is the correct voltage at
compressor terminals? Compressor has overheated - allow
time for reset (up to 3 hours) and
rectify cause
Faulty compressor run
capacitor Check visual condition of
capacitor and check uF reading
with capacitor meter. Replace capacitor as required
Motor windings faulty Check resistances of windings Windings that show open circuit could
be due to internal overload trip. Wait
for reset and recheck. If continually
open circuit - motor faulty. Replace
compressor.
Compressor seized Does compressor attempt to
start but does not run correctly
(makes humming sound)? Are
amps equivalent to LRC rating? If all electrical checks on components as
above are OK - Change compressor
Compressor runs
but no effect on
suction/discharg
e pressures Mechanical failure within
compressor Are compressor motor amps
lower than expected? If so -
potentially valve damage or
other internal wear/damage Try pump test on compressor. If test
fails - replace compressor.
Compressor
starts and stops
too quickly Operating on safety
controls Check LP switch and
compressor internal overload Rectify cause and recheck
Refrigerant levels Is there too little refrigerant in
the system causing LP switch
tripping? Check refrigerant level and adjust
accordingly
Faulty contactor (if fitted) Are the contacts chattering on
the contactor?
Contacts may be dirty or worn. Check
and replace contactor as necessary
Anti short cycle time in
controller is set too low Anti short cycle time should be
set for minimum of 3 minutes Check and rectify
Temperature differential
in controller set too low Differential should be set for
minimum of 2°C Check and rectify
Room temperature rising
too quickly Are doors open to room? Check and rectify