Carrier Omnizone 50BVC Installation, Start-Up, Service And Controls Operation And Troubleshooting page 73

PROBLEM
Unit Will Not Start.
Fan Does Not Operate.
Compressor is Noisy, But
Will Not Start.
Compressor Starts,
But Does Not Continue
to Run.
Unit is Noisy.
Unit Runs Continuously,
But Has Low Capacity.
High Discharge Pressure.
LEGEND
TXV — Thermostatic Expansion Valve
VFD — Variable Frequency Drive
Table 63 — Unit Troubleshooting
POSSIBLE CAUSE
Loss of unit power
Unit voltage not correct
Open fuse
Open protection device
Unit or motor contactor out of order
Contactor or relay overload or out of order
VFD not running
Motor defective
Broken belt
Loose electrical contact
Under voltage
Defect in compressor motor
Missing phase
Compressor seized
Compressor or contact defect
Unit is under charged
Unit is too big
Compressor is overloaded
Compressor noise
Tube vibration or condenser water problem
Unit panel or part vibrating
Unit is too small
Low refrigerant or noncondensing gas present
Compressor defect
Insufficient flow of refrigerant in evaporator
Oil in evaporator
Low airflow
Low waterflow in condenser
Dirty condenser tubes.
High temperature in condenser water
Overcharged
Noncondensing gas present
CORRECTION PROCEDURE
Check power source.
Check fuses, circuit breakers, disconnect switch.
Check electrical contacts.
Check and correct.
Check for short circuit in unit.
Check relays (phase monitor option), contacts, pressure switches.
Test and replace if necessary.
Test and replace if necessary.
Confirm VFD parameters set.
Test and replace if necessary.
Replace belt.
Tighten contact.
Check and correct.
Replace compressor.
Check and correct.
Check and replace if necessary.
Test and replace if necessary.
Check and correct any leaks. Add refrigerant.
Check load calculation.
Check protection device and replace.
Check for missing phase.
Check TXV.
Check temperature in suction discharge line.
Check TXV and replace if necessary.
Compressor rotation incorrect; check and correct.
Check internal noise.
Check and correct.
Check and tighten appropriate part.
Check load calculation.
Check for leaks and add refrigerant or gas as necessary.
Check pressure and amps. Replace if necessary.
Check filter drier and replace if necessary.
Check TXV and adjust or replace if necessary.
Check position of TXV bulb and equalizer.
Drain evaporator.
Check filters, and clean or replace as necessary.
Check coils, and clean as necessary.
Check for restrictions in ductwork.
Check fan rotation and adjust.
Check fan motor.
Check belts for wear.
Purge air.
Clean condenser.
Check water tower fans and pumps.
Check and reclaim excess charge.
Adjust subcooling.
Verify and correct.
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