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PROBLEM
No display on panel
1. No 115VAC to 2T.
Unit will no operate
2. No 24VAC to Power Supply Board.
3. 2T defective, no 24VAC output.
4. No +12V output from Power Supply Board.
"NO RUN PERM"
1. Remote cycling device open.
2. "System" switch in the OFF position.
"MOTOR CURRENT"
CONTACTOR DOES NOT ENERGIZE
Fault
1. External high pressure switch tripped.
Motor Contactor may
or may not Energize
2. External motor protector tripped.
3. Defective relay output board.
CONTACTOR ENERGIZES
1. Improper system high voltage.
2. Defective contactor contact and contactor.
3. Faulty high voltage wiring.
4. High motor current stored in memory.
5. Defective current transformer (CT).
"LOW OIL PRESS"
1. Low oil charge.
Fault
2. Too much refrigerant-in oil, particularly
3. Liquid Line Solenoid Valve (LLSV) not
4. Suction Pressure Transducer or wiring
5. Oil Pressure Transducer or wiring
"LOW SUCTION"
1. Improper Suction Pressure Cut-out
Fault
2. Low refrigerant charge.
3. Fouled filter drier.
4. Thermal expansion valve adjustment/failure.
5. Piping problems.
6. Defective suction pressure transducer.
7. Faulty wiring to transducer.
8. Check piping design
YORK INTERNATIONAL
TROUBLESHOOTING CHART
CAUSE
Contact YORK Service Before Replacing Circuit Boards!
Contact YORK Service Before Replacing Circuit Boards!
on start-up.
operating.
defective.
defective.
adjustment.
SOLUTION
1. Checking wiring and fuses (1 FU and 2 FU).
Check emergency stop contacts
2. Check wiring 2T to Power Supply Board.
3. Replace 2T.
4. Replace Power Supply Board or isolate exces-
sive load on the board.
1. Check cycling devices and thermostat connected
to terminals 13 & 14 and 13 & 15 of the TB3
Terminal Block.
2. Place switches to the ON position.
1. Check external high pressure switch, fan
operation, and discharge pressure stored in
memory. Air flow from fans must be up.
2. Check for defective External motor protector,
wiring and motor problems. Assure that motor
protector is not tripped due to external high
pressure switch.
3. Replace relay output board.
1. Check system high voltage supply.
2. Check contacts and contactor.
3. Check wiring.
4. Loose calibration resistors in J9 (SYS 1) OR
J10 (SYS 2) of power supply board.
5. CT resistance 42-44Ω.
1. Oil level should be visible in either sight glass at
all times. Add YORK "C" oil if necessary.
2. Check crankcase oil heater operation. (350 Watt
heater should be "ON" when unit is "OFF".
Measure heater current.
(Should be min. 2 amps.
3. Check wiring and LLSV.
4. Compare display to a gauge (SYS OFF).
Replace defective component.
5. Compare suction and oil gauges to display.
Replace defective component.
1. Adjust per recommended settings and restart
unit.
2. Repair leak/add refrigerant.
3. Change drier core.
4. Adjust compressor suction superheat to 15°F.
or replace power element (or valve).
5. Check piping / design.
6. Replace transducer.
7. Check wiring.
8. Modify piping design.
FORM 195.26-NM3
to
.
5
1
)
77
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