Carrier 50NQ - Manual (Page 15)

TROUBLESHOOTING CHART—COOLING CYCLE
TROUBLESHOOTING CHART—HEATING CYCLE
LOW LINE VOLTAGE
OK UNBALANCED
3 PHASE LINE
COMPRESSOK
POWER
supplì
OPEN
OEFLCIIVE RUN
i ; apaciioh
• SINCU E PHASE I
OUTDOOR
THERMOSTAT
DEFECTIVE
DEFECTIVE LOW
VOLTAGE
TRANSFORMER INDOOR IANS
CVCLINti ON
OVERLOAD LOOSE LEADS A
OUTDOOR FAN
MOTOR
FAULTY START CAP
OR RELAY ISINGLE
PHASE) OR PTC INTERNAI FAN
MOTOR KLIXON
OPEN METERING DEVICE
• RESTRICTED OR
ICE-CLOGGED
CAP TUBE PINCHED
OR BULB NOT
SENSING TRUE ODT
UNDERCHARGED STRIP HEATER RELAY
OR CÜNIACTOH
DETECTIVE
REVERSING VALVE
JAMMED IN MID
POSITION DEFROST BOARD
N C CONTACTS
OPEN OPENING IN POWER
CIRCUIT TO HEATER
ELEMENTS
SUPPLEMENTAL HEAT
RELAY ENERGIZED
OR WIRED WRONG
OPEN (Kl IXON)
OVERTEMPERATURE
THERMOSTAT
OVERCHARGE OR
NONCONDENSAOLES
IN SYSTEM DEFROST T STAT
IN POOR PHYSICAL
CONTACT WITH LINE DEFECTIVE ROOM
THEHMOSTAI
|?ND STAGEl
RESTHiCTED OR
STUCK
METERING DEVICE
DEFECTIVE DEFROST
RELAY OR DEFROST
TIMER
BAD ELECTRICAL CON
NECTION ANYWHERE
IN DEFROST CIRCUIT
A88431
15