LTI DI-FT Series, Operation & Maintenance Manual

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12
TROUBLESHOOTING
REFRIGERANT TROUBLESHOOTING
COMPLIANT PROBLEM SOLUTION
COMPRESSOR WILL NOT START
LINES DISCONNECTED / SWITCH OPEN CLOSE START ON DISCONNECT SWITCH
FUSE REMOVED OR BLOWN REPLACE FUSE
CONTROL STUCK IN OPEN POSITION REPAIR OR REPLACE CONTROL
CONTROL OFF DUE TO COLD LOCATION RELOCATE CONTROL
COMPRESSOR WILL NOT START, HUMS
BUT TRIPS OVERLOAD PROTECTOR
LOW VOLTAGE TO UNIT CALL POWER SUPPLIER
STARTING CAPACITOR DEFECTIVE REPLACE CAPACITOR
RELAY FAILING TO CLOSE REPLACE RELAY
COMPRESSOR MOTOR HAS A WINDING
OPEN OR SHORTED REPLACE COMPRESSOR
INTERNAL MECHANICAL TROUBLE IN
COMPRESSOR REPLACE COMPRESSOR
COMPRESSOR STARTS AND RUNS, BUT
SHORT CYCLES ON OVERLOAD
PROTECTOR
LOW VOLTAGE TO UNIT CALL POWER SUPPLIER
OVERLOAD PROTECTOR DEFECTIVE CHECK CURRENT, REPLACE PROTECTOR
RUN CAPACTIOR DEFECTIVE REPLACE CAPACITOR
EXCESSIVED DISCHARGE PRESSURE CHECK VENTILATION, RESTRICTIONS IN
COOLING MEDIUM, RESTRICTIONS IN
REFRIGERANT SYSTEM
COMPRESSOR TOO HOT, RETURN GAS
HOT CHECK REFRIGRANT CHARGE (FIX LEAK IF
NECESSARY)
COMPRESSOR MOTOR HAS A WINDING
SHORTED REPLACE COMPRESSOR
UNIT RUNS OKAY, BUT SHORT CYCLE ON
OVERLOAD PROTECTOR CHECK CURRENT, REPLACE PROTECTOR
THERMOSTAT DIFFERENTIAL SET TO CLSE, WIDEN
HIGH PRESSURE CUT OUT DUE TO:
INSUFFICIENT AIR, OVERCHARGE, OR AIR
IN SYSTEM REDUCE REFRIGERANT CHARGE, PURGE.
CHECK AIR SUPPLY TO CONDENSER,
REDUCE REFRIGERANT CHARGE, PURGE
UNIT OPERATES LONG OR
CONTINUOUSLY
SHORTAGE OF REFRIGERANT FIX LEAK, ADD CHARGE
CONTROL CONTACTS STUCK OR
FROZEN/CLOSED
CLEAN CONTACTS, OR REPLACE CONTROL
REFRIGERANT OR AIR CONDITIONED
SPACE HAS EXCESSIVE LOAD OR POOR
INSULATION DETERMINE FAULT AND CORRECT
EVAPORATOR COIL ICED DEFROST
RESTRICTION IN REFRIGERANT SYSTEM DETERMINE LOCATION AND REMOVE
DIRTY CONDENSER CLEAN CONDENSER
FILTER DIRTY CLEAN OR REPLACE
START CAPACITOR OPEN
RELAY CONTACTS NOT OPENING
PROPERLY
CLEAN CONTACTS OR REPLACE IF
NECESSARY
PROLONGED OPERATION ON CYCLE DUE
TO LOW VOLTAGE, IMPROPER RELAY CALL POWER SUPPLIER, OR REPLACE
RUN CAPACITOR OPEN, SHORTED OR
BLOWN
EXCESSIVE SHORT CYCLE DETERMINE REASON FOR SHORT CYCLE
IMPROPER CAPACITOR DETERMINE CORRECT SIZE AND REPLACE
EXCESSIVELY HIGH LINE (100% OF RATED-
MAX) CALL POWER SUPPLIER
SPACE TEMPERATURE TOO HIGH
CONTROL SETTING TO HIGH RESET CONTROL
INADEQUATE AIR CIRCULATION IMPROVE AIR MOVEMENT
SUCTION LINE FROSTED OR SWEATING
EXPANSION VALVE STUCK CLEAN VALVE OFF FOREIGN PARTICLES,
REPLACE IF NECESSARY
EVAPORATOR FAN NOT RUNNING DETERMINE REASON AND CORRECT
OVERCHARGE OF REFRIGERANT CORRECT CHARGE