York Millennium YCAJ150, Installation Operation & Maintenance, Page: 111 / 116

FORM 150.65-NM4
111 YORK INTERNATIONAL
No display on panel 1. No 115VAC to 2T. 1. Checking wiring and fuses (1 FU and 2
Unit will not operate FU). Check emergency stop contacts
5 to 1 .
2. No 24VAC to Power Supply Board. 2. Check wiring 2T to Power Supply Board.
3. 2T defective, no 24VAC output. 3. Replace 2T.
4. No +12V output from Power Supply 4. Replace Power Supply Board or isolate
Board excessive load on the board.
Contact YORK Service Before Replacing Circuit Boards!
“NO RUN PERM” 1. No Flow 1. Check chilled liquid flow.
2. Flow switch installed improperly. 2. Check that flow switch is installed
according to manufacturer’s instructions.
3. Defective flow switch. 3. Replace flow switch.
4. Remote cycling device open. 4. Check cycling devices connected to
terminals 13 & 14 of the TB3 Terminal
Block.
5. “System” switch in the OFF position 5. Place switches to the ON position.
“MOTOR CURRENT” CONTACTOR DOES NOT ENERGIZE
FAULT
1. External high pressure 1. Check external high pressure switch, fan
switch tripped. operation, and discharge pressure stored
in memory. Air flow from fans must be up.
2. External motor protector tripped. 2. Check for defective External motor
protector, wiring and motor problems. As-
sure that motor protector is not tripped due
Motor contactor may to external high pressure switch.
or may not energize 3. Defective relay output board. 3. Replace relay output board.
CONTACTOR ENERGIZES
1. Improper system high voltage. 1. Check system high voltage supply.
2. Defective contactor contacts 2. Check contacts and contactors.
and contactor.
3. Faulty high voltage wiring. 3. Check wiring.
4. High motor current stored in memory. 4. Loose calibration resistors in J9 (SYS 1)
or J10 (SYS 2) of power supply board.
5. Defective current transformer (CT). 5. CT resistance 42-44
Ω
.
Contact YORK Service Before Replacing Circuit Boards or C.T.s!
“LOW OIL PRESS” 1. Low oil charge. 1. Oil level should be visible in either sight
FAULT glass at all times. Add YORK “C” oil if
necessary.
2. Too much refrigerant-in oil, partic- 2. Check crankcase oil heater operation.
ularly on start-up. (350 Watt heater should be “ON” when
unit is “OFF”. Measure heater current.
(Should be min. 2 amps.)
3. Liquid Line Solenoid Valve (LLSV) 3. Check wiring and LLSV.
not operating.
4. Suction Press. Transducer or wiring 4. Compare display to a gauge (SYS OFF).
defective. Replace defective component.
5. Oil Press. Transducer or wiring 5. Compare suction and oil gauges to display.
defective. Replace defective component.
TROUBLESHOOTING CHART
PROBLEM CAUSE SOLUTION