Carrier Ecologic Series 3 Controls, Start-Up, Operation, Service, And Troubleshooting page 67

SYMPTOMS
COMPRESSOR DOES NOT
RUN
COMPRESSOR CYCLES
OFF ON LOW PRESSURE
COMPRESSOR SHUTS
DOWN ON HIGH PRESSURE
CONTROL
UNIT OPERATES LONG OR
CONTINUOUSLY
SYSTEM NOISES
COMPRESSOR LOSES OIL
HOT LIQUID LINE
FROSTED LIQUID LINE
COMPRESSOR LOADERS
NOT WORKING PROPERLY
*30GX251, 265 sizes have two Circuit A discharge and liquid valves.
Table 46 — Compressor Control Troubleshooting
CAUSE
Power line open
Control fuse open
High-Pressure Switch (HPS) tripped
Tripped motor overload
Loose terminal connection
Improperly wired controls
Low line voltage
Compressor motor defective
Seized compressor
Pre-lubrication not successful
Loss of charge
Bad transducer
Low refrigerant charge
Failed expansion device
High-pressure switch erratic in action
Compressor discharge valve partially closed
Condenser fan(s) not operating (air cooled units)
Condenser coil plugged or dirty (air cooled units)
Condenser water valve not operating (water
cooled units)
Circuit overcharged
Liquid valve closed*
Low refrigerant charge
Control contacts fused
Partially plugged or plugged expansion valve or
filter drier
Defective insulation
Service load exceeding design capacity
Inefficient compressor
Piping vibration
Expansion valve hissing
Compressor noisy
Leak in system
Mechanical damage to rotors
Shortage of refrigerant due to leak
Shutoff valve partially closed or restricted
Burned out coil
Defective capacity control valve
Miswired solenoid
Check main disconnect.
Check control circuit for ground or short. Replace fuse.
Move LOCAL/OFF/REMOTE switch to OFF position
then back to LOCAL or REMOTE position.
Check the controls. Find cause of trip. Reset overload.
Check connections.
Check wiring and rewire.
Check line voltage. Determine location of voltage drop
and remedy deficiency.
Check motor winding for open or short. Replace
compressor if necessary.
Replace compressor.
Check oil pump operation, oil pressure transducer, verify
oil level/flow switch operation.
Repair leak and recharge.
Replace transducer.
Add refrigerant.
Repair/replace as needed.
Replace switch.
Open valve or replace if defective.
Check wiring. Repair or replace motor(s) if defective.
Clean coil.
Check wiring. Repair or replace valve if defective.
Clean condenser.
Open valve or replace if defective.
Add refrigerant.
Replace control.
Clean or replace.
Replace or repair.
Keep doors and windows closed.
Check loader solenoid valves. Replace if necessary.
Support piping as required.
Add refrigerant.
Check for plugged liquid line filter drier.
Replace compressor (worn bearings).
Check for loose compressor bolts securing compressor to
cooler.
Find and repair leak.
Replace compressor.
Repair leak and recharge.
Open valve or remove restriction.
Replace coil.
Replace valve.
Rewire correctly.
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REMEDY