York YCAL0014SC, Installation Operation & Maintenance, Page: 105 / 136

YORK INTERNATIONAL
105
FORM 150.62-NM1
TROUBLESHOOTING
PROBLEM CAUSE SOLUTION
No display on panel. 1. No 115VAC to 1T. 1a. Check wiring and fuse
Unit will not operate. 3FU
b. Check wiring emergency
stop contacts 5 to L of CTB2
Terminal Block.
c. Replace 1T
2. No 24VAC to Microboard 2. Check wiring 1T to
Microboard.
3. 1T defective, no 3. Replace 1T
24VAC output.
4. Short in wire to temp. sensors 4. Unplug connections at
or pressure transducers. Microboard to isolate.
5. Defective Microboard 5. Replace Microboard.
or Display board.
NOTE: Contact YORK
Service before
Replacing circuit Boards!
“FLOW SWITCH/REM 1. No chilled liquid flow. 1. Check chilled liquid flow.
STOP NO RUN PERMISSIVE”
2. Flow switch improperly 2. Check that the flow switch
installed. 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 CTB1
Terminal Block.
“LOW SUCTION PRESSURE” 1. Improper suction pressure 1. Adjust per recommended
FAULT cut-outs adjustments. settings.
2. Low refrigerant charge. 2. Repair leak if necessary
and add refrigerant.
3. Fouled filter dryer. 3. Change dryer/core.
TABLE 50 – TROUBLESHOOTING
CONT’D
3