J&E Hall V3 FUSION Technical Manual page 29

FAULT
Compressor starting too
frequently
Discharge gas bleeding into
suction side
CONDENSER FAN
Power supply
Compressor contactor not
pulled in
Compressor contactor
pulled in
Condenser fan will
not run
Being controlled by FSC (if
fitted)
Fan capacitor fault
Motor fault
Is fan being controlled by
FSC?
Condenser fan
runs but only
slowly
FSC faulty
SYSTEM
Insufficient cooling
Lack of refrigerant
Condenser coil dirty
Lack of ventilation to unit
Compressor not pumping
efficiently
System settings
Service valves do not open
correctly
Restriction in
piping/component
Head pressure too
Condenser coil dirty
high
System overcharged with
refrigerant
Condenser fan not running
FSC (if fitted) not set
correctly
Lack of ventilation to unit
System load too high
(overstocked, door open on
cold-room)
Issue: 01.06.2023
POSSIBLE CAUSE
Are controls set correctly - is the
differential on thermostat or LP
switch too small?
Is the liquid line solenoid valve
allowing refrigerant to pass when
closed?
Does suction pressure rise
abnormally when compressor
stops or compressor fails to pump
down correctly?
See compressor will not start
section
See compressor will not start
section
Is voltage being switched across
contactor?
Is system operating pressure
below FSC setting?
Check visual condition of
capacitor and check capacitance
reading with capacitor meter.
If FSC fitted - bypass FSC to test
motor. If motor still does not run -
motor is faulty
Is head pressure under control
(~14/15 bar on R448A/449A)
and fan speed increases as head
pressure rises?
Is head pressure above 16 bar
(R448/449A)?
If fan runs slowly even after
adjusting FSC with head pressure
rising - FSC may be faulty
Is sight glass flashing continuously?
Visual check of coil condition
Any obstructions around unit?
Carry out pump test on
compressor
Controls (inc thermostat) set
correctly?
T.E.V. Superheat
Are valves fully open?
Is the filter drier blocked?
Sweating/frosting on outlet of
drier indicates a blockage
Damage to piping
Visual check of coil condition
Is head pressure high but liquid
line cool to touch?
See above (fan will not run)
Check setting against gauge
pressure
Any obstructions around unit?
CHECK
Check and adjust
Check valve and clean seat or
replace as necessary if damaged
Compressor valve reeds may be
damaged - replace compressor
See compressor will not start
section
See compressor will not start
section
If yes - check voltage to FSC and
to fan motor. If correct voltage
present at motor - fan faulty.
Replace fan
If no. Replace faulty contactor
If yes - all OK (check fan operates
when pressure rises)
Replace capacitor if required
Replace motor
All OK
Check setting of FSC. Adjust if
necessary.
Change FSC
Leak test system and top up with
refrigerant
Clean condenser coil
Clear same to ensure good
ventilation
Replace compressor if fails pump
test
Adjust as necessary
Adjust as necessary
Adjust as necessary
Replace filter drier
Replace piping as required
Clean condenser coil
Reclaim refrigerant/recharge
correctly
See above
Adjust as necessary
Clear same to ensure good
ventilation
Reduce loading
SOLUTION
Page 26