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www.breathe-safe.com.au
Page
35
Issue date
:
Controlled document
:
Revision:
WA900-3EO
Solutions
Causes
Symptoms
System Produces
No Cooling
Suction gauge low.
Discharge gauge low.
Suction gauge high.
Discharge gauge high.
Only slight pressure
variations at change in
compressor speed
Discharge gauge low.
Suction gauge low.
Bubbles in the sight glass.
TX Valve sweating or
frosty.
No air flow at louvers
Evaporator sweating or
frosty.
Frosty at point of line
blockage
No bubbles in sight glass.
Suction gauge low or zero.
Discharge gauge low or
zero.
Compressor
Operative?
No
Yes
System too low on
refrigerant due to slow
leak.
Supply air fan inoperative.
TX Valve jammed shut.
Blocked Evaporator.
Blocked Condenser.
Locate leak & repair.
Evacuate & charge system.
Replace TX Valve.
Determine cause. Repair or
replace blower motor
Check and clean coil.
TX Valve jammed open.
Remove & clean or replace
the TX valve.
System over charged.
Correct refrigerant charge.
Compressor reed valves
inoperative.
Replace compressor reed
valves.
Blocked receiver drier
Blocked TX Valve filter
screen.
Replace receiver drier
Remove and clean or
replace filter screen.
Electrical fault
Check wiring, fuses or
circuit breaker.
Complete loss of charge.
LP switch tripped.
Compressor clutch coil
burnt out.
Insert small amount of
charge to verify leak.
Evacuate & charge system
Replace clutch.
Thermostat inactive due to
Tripped circuit breaker.
Loose or broken drive belt.
Check wiring and reset
circuit breaker.
Tighten or replace worn
belt.
FAULT DIAGNOSIS
