58
Table 44 — Cooling Service Analysis
LEGEND
PROBLEM CAUSE
REMEDY
Compressor and Fan Will Not Start.
Power failure.
Call power company.
Fuse blown or circuit breaker tripped. Check CB1, CB2, and
CB3.
Replace fuse or reset circuit breaker.
Disconnect off.
Power disconnect.
Compressor time guard to prevent short cycling.
Check using ComfortLink™ Scrolling Marquee.
Thermostat or occupancy schedule set point not calling for
Cooling.
Check using ComfortLink Scrolling Marquee.
Outdoor temperature too low.
Check Compressor Lockout Temperature using
ComfortLink Scrolling Marquee.
Active alarm.
Check active alarms using ComfortLink Scrolling
Marquee.
Compressor Cycles (other than
normally satisfying thermostat).
Insufficient line voltage.
Determine cause and correct.
Active alarm.
Check active alarms using ComfortLink Scrolling
Marquee.
Compressor Operates Continuously.
Unit undersized for load.
Decrease load or increase size of unit.
Thermostat or occupancy schedule set point too low.
Reset thermostat or schedule set point.
Dirty air filters.
Replace filters.
Low refrigerant charge.
Check pressure, locate leak, repair, evacuate, and recharge.
Condenser coil dirty or restricted.
Clean coil or remove restriction.
Excessive Condenser Pressures.
Loose condenser thermistors.
Tighten thermistors.
Dirty condenser coil.
Clean coil.
Refrigerant overcharge.
Recover excess refrigerant.
Faulty TXV.
1. Check TXV bulb mounting and secure tightly to suction
line and insulate.
2. Replace TXV (and filter drier) if stuck open or closed.
Condenser air restricted or air short cycling.
Determine cause and correct.
Restriction in liquid tube.
Remove restriction.
Condenser Fans Not Operating.
No Power to contactors.
Fuse blown or plug at motor loose.
Excessive Suction Pressure.
High heat load.
Check for sources and eliminate
Faulty TXV.
1. Check TXV bulb mounting and secure tightly to suction
line and insulate.
2. Replace TXV (and filter drier) if stuck open or closed.
Refrigerant overcharged.
Recover excess refrigerant.
Suction Pressure Too Low.
Dirty air filters.
Replace air filters.
Low refrigerant charge.
Check pressure, locate leak, repair, evacuate, and recharge.
Faulty TXV.
1. Check TXV bulb mounting and secure tightly to suction
line and insulate.
2. Replace TXV (and filter drier) if stuck open or closed.
Insufficient evaporator airflow.
Check belt tension. Check for other restrictions.
Temperature too low in conditioned area (low return-air
temperature).
Reset thermostat or occupancy schedule.
CB
— Circuit Breaker
TXV
— Thermostatic Expansion Valve
Содержание 48PG24
Страница 68: ...68 Fig 14 Low Voltage Control Schematic 48PG20 28 Units without Humidi MiZer System a48 7627...
Страница 69: ...69 Fig 15 Low Voltage Control Schematic 48PG20 28 Units with Humidi MiZer System a48 8227...
Страница 70: ...70 Fig 16 Low Voltage Control Schematic 50PG20 28 Units without Humidi MiZer System a48 7778...
Страница 71: ...71 Fig 17 Low Voltage Control Schematic 50PG20 28 Units with Humidi MiZer System a50 8101...
Страница 72: ...72 Fig 18 Power Schematic Units without Humidi MiZer System a48 7628...
Страница 73: ...73 Fig 19 Power Schematic Units with Humidi MiZer System a48 8228...
Страница 74: ...74 Fig 20 Component Arrangement Units without Humidi MiZer System a48 8229...
Страница 75: ...75 Fig 21 Component Arrangement Units with Humidi MiZer System a48 8230...
Страница 105: ......
