York Millennium YCAS 316, Installation Operation & Maintenance, Page: 138 / 144

138
YORK INTERNATIONAL
TROUBLESHOOTING
PROBLEM CAUSE SOLUTION
No display on panel. 1. No 115VAC to 2T. 1. Check wiring and fuses
Unit will not operate. (IFU and 2 FU).
Check emergency stop
contacts 5 to 1 of TB1
Terminal Block.
2. No 24VAC to Power Supply 2. Check wiring 2T to
Supply Board. Power Supply Board.
3. 2T defective, no 3. Replace 2T
24VAC output.
4. No + 12V output (J2) from 4. Replace Power Supply
Power Supply Board. Board or load on the board.
NOTE: Contact YORK
Service before
Replacing circuit Boards!
“NO RUN PERMISSIVE” 1. No chilled liquid flow. 1. Check chilled liquid flow.
2. Flow switch improperly 2. Check that the flow switch
installed. is installed according to
manuafacturer’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 5. Place switches to the
OFF position. ON position.
“LOW OIL DIFFERENTIAL” 1. Faulty oil or suction pressure 1. Check / replace
FAULT transducer or wiring transducers or repair wiring.