Carrier 30HH - Manual (Page 46)

30HH,HJ
MAINTENANCE
Carrier
TROUBLE DIAGNOSIS CHART
SYMPTOMS CAUSE REMEDY
A. Compressor does
not run
Power line open Reset circuit breaker
Control circuit fuse blown Check control circuit for ground
or short, repair and replace fuse
Safety thermostat tripped Reset thermostat
Tripped starter overloads See starters and overloads (check
the controls)
Condenser circulating pump
not running
Power off - restart
Pump binding - free pump
Incorrect wiring - rewire
Pump motor burned out - replace
Control stuck open
Loose terminal connection
Improperly wired controls
Low line voltage
Compressor motor effective
Seized compressor
Replace control
Check connections
Check wiring and rewire
Check line voltage - determine
location of voltage drop
Check motor winding for open or short.
Replace compressor, if necessary
Replace compressor
B. Compressor cycles on
low pressure control
Low pressure control
erratic in action
Raise differential setting
Check capillary for pinches
Replace control
Compressor suction valve
leaking
Replace valve plate
Compressor suction shut-off
valve partially closed
Open valve
Low refrigerant charge Add refrigerant
Plugged compressor suction
strainer
Clean strainer
C . Compressor cycles on
high pressure control
High pressure control
erratic in action
Check capillary tube for pinches
Set control as required
Compressor discharge valve
partially closed
Open valve
Air in system Purge
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