Carrier 50JS instruction manual Cooling and Heating Troubleshooting Chart contd, Start-Upchecklist

Cooling and Heating Troubleshooting Chart (cont'd)

SYMPTOM	CAUSE	REMEDY
Suction pressure too low	(Cool) Dirty air filter	Replace filter
	(Heat) Outdoor coil frosted	Move timer on control board to 30 min. between
		defrost cycles
	Low refrigerant charge	Check for leaks, repair and recharge
	Metering device or low side restricted	Remove source of restriction
	(Cool) Insufficient coil airflow	Increase air quantity
		Check filterÐreplace if necessary
	(Cool) Temperature too low in conditioned area	Reset thermostat
	(Cool) Outdoor ambient below 40°F	Install low-ambient kit
	Field-installed filter-drier restricted	Replace
Compressor runs but outdoor fan does not	NC (normally closed) contacts on defrost board	Check condition of relay on board
	open	Replace if necessary
IFM does not run	Blower wheel not secured to shaft	Properly tighten blower wheel to shaft
	Insufficient voltage at motor	Determine cause and correct
	Power connectors not properly sealed	Connectors should snap easily; do not force
	Motor programmed with a delay profile	Allow a few min. for motor to shut off
IFM runs when it should be off	With thermostat in off state, the voltage on G,	If measured voltage is more than 1/2, the ther-
	Y1,Y, Y2, W with respect to common, should be	mostat is incompatible with motor
	1/2 of actual low voltage supply	If voltage is less than 1/2, the motor has failed
	Water dripping into motor	Verify proper drip loops in connector wires
IFM operation is intermittent	Connectors not firmly sealed	Gently pull wires individually to be sure they are
		crimped into the housing
IFMÐIndoor Fan Motor
	START-UP CHECKLIST
	(REMOVE AND STORE IN JOB FILE)
I. PRELIMINARY INFORMATION
Model No
Serial No
Date
Technician

II.PRE-START-UP

___ Verify that all packing materials have been removed from unit

___ Remove all shipping holddown bolts and brackets per installation instructions

___ Verify that condensate connection is installed per installation instructions

___ Check all electrical connections and terminals for tightness

___ Check that indoor (evaporator) air filter is clean and in place

___ Verify that unit installation is level

___ Check fan wheel and propeller for location in housing and setscrew tightness

III. START-UP

Supply Voltage: L1-L2 __________ L2-L3 _________ L3-L1 __________

Compressor Amps: L1 __________ L2 _________ L3 __________

Indoor Fan Amps: __________

TEMPERATURE

Outdoor-Air Temperature: __________ DB

Return-Air Temperature: __________ DB __________ WB

Heat Pump Supply Air: __________

Electric Heater Supply Air: __________

PRESSURES

Refrigerant Suction __________ psig

Refrigerant Discharge __________ psig

___ Verify refrigerant charge using charging tables

___ Verify 3-phase scroll compressor is rotating in correct direction

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