Rheem RA17 Series, Installation Instructions Manual

Page: 47 / 56

47
Diagnostics
SYMPTOM POSSIBLE CAUSE REMEDY
Unit will not run • ower o or loose electrical connection
• Thermostat out of calibration set too high
• Defective control board
• lown fuses tripped brea er
• Transformer defective
• igh-pressure control open
Low-pressure control open
• iswiring of communications communication
light on continuously)
• hec for correct voltage at line voltage connections in
condensing unit.
• eset.
• hec control board diagnostic codes.
• eplace fuses reset brea er.
• hec wiring. eplace transformer.
• eset. Also see high head pressure remedy. The high-
pressure control opens at 610 PSIG.
• hec communication wiring.
Outdoor fan runs,
compressor doesn't
• un or start capacitor defective
• ontactor defective
• oose connection
• ompressor stuc , grounded or open motor
winding, open internal overload.
• ow-voltage condition
• eplace.
• eplace.
• hec for correct voltage at compressor. hec and
tighten all connections.
• ait at least 3 hours for overload to reset. If still open,
replace the compressor.
• Add start it components.
Insu cient cooling • Improperly si ed unit
• Improper indoor air ow
• Incorrect refrigerant charge
• Air, noncondensibles, or moisture in system
• ad ID
• ecalculate load.
• hec . Should be approximately 400 per ton.
• harge per procedure attached to unit service panel.
• ecover refrigerant. vacuate and recharge. Add lter
drier.
• eplace
Compressor short
cycles • Incorrect voltage
• Defective overload protector
• efrigerant undercharge
• At compressor terminals, voltage must be 10 of
nameplate marking when unit is operating.
• eplace. hec for correct voltage.
• Add refrigerant.
Registers sweat • ow indoor air ow • Increase speed of blower or reduce restriction.
eplace air lter.
High head, low vapor
pressures
• estriction in liquid line, expansion device, or
lter drier
• ad
• emove or replace defective component.
• erify thermistor and pressure transducer connection
and operation.
High head, high
or normal vapor
pressure – Cooling
mode
• Dirty outdoor coil
• efrigerant overcharge
• utdoor fan not running
• Air or noncondensibles in system
• lean coil.
• orrect system charge.
• epair or replace.
• ecover refrigerant. vacuate and recharge.
Low head, high vapor
pressures
• in bypass mode
• ad compressor
• erify thermistor and pressure transducer connection
and operation.
• eplace compressor.
Low vapor, cool
compressor, iced
indoor coil
• ow indoor air ow
• perating below 65 outdoors
• oisture in system
• losed ID circuit
• Increase speed of blower or reduce restriction.
eplace air lter.
• Add ow Ambient it.
• ecover refrigerant. vacuate and recharge. Add lter
drier.
• epair or replace ID coil
High vapor pressure • xcessive load
• Defective compressor
• echec load calculation.
• eplace.
Fluctuating head and
vapor pressures
• hunting
• Air or noncondensibles in system
• hec thermistor to vapor line connection.
• hec air distribution on coil.
• hec suction thermistor and pressure transducer
and operation.
• ecover refrigerant. vacuate and recharge.
• emove and con rm movement. lean inside
with nitrogen to remove any debris then reinstall.
Gurgle or pulsing
noise at expansion
device or liquid line
• Air or noncondensibles in system • ecover refrigerant. vacuate and recharge.
DIAGNOSTICS
General Troubleshooting Chart
WARNING:
Disconnect all power to
unit before servicing. Contactor may break only one
side. Failure to shut off power can cause electrical
shock resulting in personal injury or death.