Carrier 48PG03-16 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 84

PROBLEM
Compressor and Fan Will Not Compressor and Fan Will Not
Start. St t
Compressor Cycles (other than Compressor Cycles (other than
normally satisfying thermostat). ll ti f i th t t)
Compressor Operates Compressor Operates
C Continuously. ti l
Excessive Condenser Pressures. Excessive Condenser Pressures.
Condenser Fans Not Operating.
Excessive Suction Pressure. Excessive Suction Pressure.
Suction Pressure Too Low. Suction Pressure Too Low.
LEGEND
CB --- --- Circuit Breaker
TXV --- --- Thermostatic Expansion Valve
Table 93—Cooling Service Analysis
CAUSE
Power failure.
Fuse blown or circuit breaker tripped. Check CB1, CB2,
and CB3.
Disconnect off.
Compressor time guard to prevent short cycling.
Thermostat or occupancy schedule set point not calling
for Cooling.
Outdoor temperature too low.
Active alarm.
Insufficient line voltage.
Active alarm.
Unit undersized for load.
Thermostat or occupancy schedule set point too low.
Dirty air filters.
Low refrigerant charge.
Condenser coil dirty or restricted.
Loose condenser thermistors.
Dirty condenser coil.
Refrigerant overcharge.
Faulty TXV.
Condenser air restricted or air short cycling.
Restriction in liquid tube.
No Power to contactors.
High heat load.
Faulty TXV.
Refrigerant overcharged.
Dirty air filters.
Low refrigerant charge.
Faulty TXV.
Insufficient evaporator airflow.
Temperature too low in conditioned area (low return-air
temperature).
Call power company.
Replace fuse or reset circuit breaker.
Power disconnect.
Check using ComfortLink™ Scrolling Marquee.
Check using ComfortLink Scrolling Marquee.
Check Compressor Lockout Temperature using
ComfortLink Scrolling Marquee.
Check active alarms using ComfortLink Scrolling
Marquee.
Determine cause and correct.
Check active alarms using ComfortLink Scrolling
Marquee.
Decrease load or increase size of unit.
Reset thermostat or schedule set point.
Replace filters.
Check pressure, locate leak, repair, evacuate, and re-
charge.
Clean coil or remove restriction.
Tighten thermistors.
Clean coil.
Recover excess refrigerant.
1. Check TXV bulb mounting and secure tightly to suc-
tion line and insulate.
2. Replace TXV (and filter drier) if stuck open or closed.
Determine cause and correct.
Remove restriction.
Fuse blown or plug at motor loose.
Check for sources and eliminate
1. Check TXV bulb mounting and secure tightly to suc-
tion line and insulate.
2. Replace TXV (and filter drier) if stuck open or closed.
Recover excess refrigerant.
Replace air filters.
Check pressure, locate leak, repair, evacuate, and re-
charge.
1. Check TXV bulb mounting and secure tightly to suc-
tion line and insulate.
2. Replace TXV (and filter drier) if stuck open or closed.
Check belt tension. Check for other restrictions.
Reset thermostat or occupancy schedule.
84
REMEDY