Carrier 50SX024-060, 50SS018-060 owner manual Troubleshooting Cooling Chart, Symptom Cause Remedy

Page 42

TROUBLESHOOTING COOLING CHART

SYMPTOM

CAUSE

REMEDY

Compressor and con-

Power failure

Call power company.

denser fan will not

 

 

Fuse blown or circuit breaker tripped

Replace fuse or reset circuit breaker.

start.

Defective thermostat, contactor, transformer,

Replace component.

 

 

or control relay

 

 

Insufficient line voltage

Determine cause and correct.

 

Incorrect or faulty wiring

Check wiring diagram and rewire correctly.

 

Thermostat setting too high

Lower thermostat setting below room temperature.

 

Single-phase units with scroll compressor

DO NOT bypass this compressor time delay Ð wait

 

(50SS048,060 and 50SX) have a 5-minute time delay

for 5 minutes until time-delay relay is deenergized.

Compressor will not

Faulty wiring or loose connections in

Check wiring and repair or replace.

start but condenser

compressor circuit

 

fan runs.

Compressor motor burned out, seized, or

Determine cause. Replace compressor.

 

 

internal overload open

 

 

Defective run/start capacitor, overload,

Determine cause and replace.

 

or start relay

 

 

One leg of 3-phase power dead

Replace fuse or reset circuit breaker.

 

 

Determine cause.

Three-phase scroll

Scroll compressor is rotating in the

Correct the direction of rotation by reversing the

compressor

wrong direction

3-phase power leads to the unit.

(50SS048, 060;

 

 

50SX036-060

 

 

units only) makes ex-

 

 

cessive noise, and

 

 

there may be a low

 

 

pressure differential.

 

 

Compressor cycles

Refrigerant overcharge or undercharge

Reclaim refrigerant, evacuate system, and recharge

(other than normally

 

to capacities shown on nameplate.

satisfying thermostat).

 

 

Defective compressor

Replace and determine cause.

 

 

Insufficient line voltage

Determine cause and correct.

 

Blocked condenser

Determine cause and correct.

 

Defective run/start capacitor, overload

Determine cause and replace.

 

or start relay

 

 

Defective thermostat

Replace thermostat.

 

Faulty condenser-fan motor or capacitor

Replace.

 

Restriction in refrigerant system

Locate restriction and remove.

Compressor operates

Dirty air ®lter

Replace ®lter.

continuously.

Unit undersized for load

Decrease load or increase unit size.

 

 

Thermostat set too low

Reset thermostat.

 

Low refrigerant charge

Locate leak, repair and recharge.

 

Leaking valves in compressor

Replace compressor.

 

Air in system

Reclaim refrigerant, evacuate system and recharge.

 

Condenser coil dirty or restricted

Clean coil or remove restriction.

Excessive head

Dirty air ®lter

Replace ®lter.

pressure.

 

 

Dirty condenser coil

Clean coil.

 

 

Refrigerant overcharged

Reclaim excess refrigerant.

 

Air in system

Reclaim refrigerant, evacuate system and recharge.

 

Condenser air restricted or air short-cycling

Determine cause and correct.

Head pressure too low.

Low refrigerant charge

Check for leaks, repair and recharge.

 

Compressor valves leaking

Replace compressor.

 

Restriction in liquid tube

Remove restriction.

Excessive suction

High heat load

Check for source and eliminate.

pressure.

 

 

Compressor valves leaking

Replace compressor.

 

 

Refrigerant overcharged

Reclaim excess refrigerant.

Suction pressure too

Dirty air ®lter

Replace ®lter.

low.

 

 

Low refrigerant charge

Check for leaks, repair and recharge.

 

 

Metering device or low side restricted

Remove source of restriction.

 

Insufficient evaporator air¯ow

Increase air quantity. Check ®lter Ð replace if

 

 

necessary.

 

Temperature too low in conditioned area

Reset thermostat.

 

Outdoor ambient below 40 F

Install low-ambient kit.

 

Field-installed ®lter-drier restricted

Replace.

 

 

 

42

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Contents Contents Safety ConsiderationsUnit Dimensions Units 50SS018-042 with Optional Base Rail Dimensions Units 50SS048,060 Without Base Rail Dimensions Units 50SS048,060 With Optional Base Rail Dimensions Units 50SX024-036 Without Base Rail Dimensions Units 50SX024-036 With Optional Base Rail Dimensions Units 50SX042-060 Without Base Rail Matl CharacteristicsCond Ð Unit Electrical Unit WTDimensions Units 50SX042-060 With Optional Base Rail Corner WT Lb/Kg 50SX Part Number ``ACurb Receiving and Installation Check EquipmentProvide Unit Support Suggested Rigging for Units Without Base Rail Physical Data Ð Unit 50SS Physical Data Ð Unit 50SXArea Not To Be Drilled SizeEvaporator Coil Access Panel Indoor Blower Access Panel Field-Fabricated Duct Cover Provide for Condensate Disposal Filler Bracket and Blower ShelfInstall Electrical Connections Condensate TrapÐ Electrical Data Ð 50SS Units Ð Electrical Data Ð 50SX Units Typical Duct Panel Knockouts CTD ICMIFO PRE-START-UP TranStart-Up Cooling Section and Make Adjustments START-UPTemp F Evap AIR Ð CFM Ð Superheat Charging Table, 50SS018Ð Superheat Charging Table, 50SS024 AIR ENTÐ Superheat Charging Table, 50SS042 Ð Superheat Charging Table, 50SS030Ð Superheat Charging Table, 50SS036 10001600 Ð Superheat Charging Table, 50SX024 Ð Superheat Charging Table, 50SX0301995 Ð Superheat Charging Table, 50SX048 Ð Superheat Charging Table, 50SX036Ð Superheat Charging Table, 50SX042 1200Superheat Required Suction-Tube Temperature FÐ Superheat Charging Table, 50SX060 Temp FMode FAN Cooling Heating TerminalOption Description Sequence of Operation Ð STD NON-ICM Units Unit Motor 460 V Horizontal Discharge Size SpeedUnit Motor AIR 460 Volt Horizontal Discharge 048² Unit Motor AIR 460 Volt Vertical Discharge SizeSpeed Delivery Unit 50SX FAN only CoolingAccessory Electric Heater Pressure Drop in. wg Wet Coil Pressure DropFilter Pressure Drop in. wg Unit Top Removal MaintenanceAir Filter Evaporator Blower and MotorCondenser Coil, Evaporator Coil, and Conden Condenser FanTroubleshooting Cooling Chart Symptom Cause RemedyTroubleshooting Cooling Chart Page Page Packaged Service Training Page Remove and Store in Job File Preliminary InformationIII. START-UP