Marstair 526 HL Series, Техническое руководство, Страница: 31 / 31

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FAULT FINDING
CONDITION POSSIBLE CAUSE ACTION
A Indoor fan motor will not run
No electric supply at socket or switched fuse
box Check fuse rating and replace if necessary.
Check for loose electrical connections
Unit wiring fault Check wiring and connections
Fan motor capacitor defective Replace if faulty
Fan motor defective Replace if faulty
Internal fuse blown Clear fault and replace fuse
B Inadequate cooling or heating Dirty evaporator fins/filter Clean if blocked
Evaporator motor not running As in section A
Refrigerant shortage or excess
Check for leaks. Repair, evacuate and
recharge or check for high head pressure and
recover refrigerant if necessary
Faulty thermostat or incorrectly set Replace if faulty
Dirty condenser Clean if necessary
Faulty compressor Replace
LP cutout circuit open (if fitted) Check as refrigerant shortage or excess
C
Compressor and outdoor fan motor
will not run
LP cutout circuit open (if fitted) Check as above
No electric supply at socket or switch fuse box
Check fuse rating and replace if necessary.
Check for loose electrical connection.
Unit wiring fault Check wiring and connections
Capacitor, thermostat, relay or overload
defective
Replace if faulty
Compressor failure Replace if faulty
Controls not set properly Check and rectify
Off cycle delay operating If applicable, wait 3 minutes
High condensate level detected See G
D
System runs for long periods and
will not cycle
Unit underrated for conditioned area Check heat load against capacity
Thermostat not operating correctly Check wiring, position of phial and operation
Refrigerant shortage
Check for leaks. Recover, repair, evacuate
and recharge
Indoor coil dry or partly sweating Dirty condenser Clean fins if necessary
E Indoor coil frosting Refrigerant shortage
Check for leaks. Recover, repair, evacuate
and recharge
Dirty evaporator fins/filter Clean if blocked
Running in cool ambient without a head
pressure controller
Fit head pressure controller
If room temperature is also low Thermostat set too low or cooling permanentlyReset or replace
F Noisy unit Fan fouling cowl (outdoor unit) Realign fan
Worn motor bearing Replace motor
Casing or piping vibration Check cause and rectify
Loose parts or mounting Find and tighten
Bent fan blade Replace fan
G Water leaking from unit Blocked drain Clear obstruction
Units with condensate pump No supply to pump or loose connection Secure the supply
Fouled sensor Clean sensor
Pumping slowly Check drain pipes; if clear, replace pump
Pump windings shorted Replace pump
H Pump always runs Faulty sensor or pcb Replace sensor or pcb
I
No heating (Heat pump systems
only)
Controls not set for heating Reset
Unit wiring fault Check wiring and connections
Dirty evaporator fins/filter Clean
Faulty thermostat Check for signal; replace if faulty
Reversing valve jammed A light tap may free it; preferably replace
J
Overload tripped on three phase
units
High voltage supply Max rated voltage 254v -- check supply
Compressor failure Replace
Fuses blown
Replace fuses and investigate reason for
fuses blowing