Table 37 - Troubleshooting - York YCAL0019 Installation, Operation And Maintenance Manual

SECTION 9 – SERVICE AND TROUBLESHOOTING

TABLE 37 - TROUBLESHOOTING

PROBLEM
NO DISPLAY ON PANEL
UNIT WILL NOT OPERATE
FLOW SWITCH/REM
STOP NO RUN PERMISSIVE
LOW SUCTION PRESSURE FAULT
212
CAUSE
1. No 115VAC to 24VAC Transformer.
2. No 24VAC to Microboard.
3. Control Transformer defective, no
24VAC output.
4. Short in wire to temperature sensors
or pressure transducers.
5. Defective IPU & I/O board or the
Display board.
1. No chilled liquid flow.
2. Flow switch improperly installed.
3. Defective flow switch.
4. Remote cycling device open.
1. Improper suction pressure cutouts
adjustments.
2. Low refrigerant charge.
3. Fouled filter dryer.
4. TXV defective.
5. Reduced flow of chilled liquid through
the cooler.
6. Defective suction pressure transducer/
low pressure switch or wiring.
7. LLSV defective.
FORM 150.67-NM1
ISSUE DATE: 4/28/2017
SOLUTION
1a. Check wiring and fuse 1FU.
1b. Check wiring emergency stop
contacts 5 to L of TB1 terminal
block.
1c. Replace Control Transformer.
2. Check wiring Control
Transformer to Microboard.
3. Replace Control Transformer.
4. Unplug connections at IPU II and
I/O board to isolate.
5. Replace IPU & I/O board or the
Display board.
Contact Johnson
Controls Service
before replacing
circuit boards.
1. Check chilled liquid flow.
2. Check that the flow switch
is installed according to
manufacturer's instructions.
3. Replace flow switch.
4. Check cycling devices
connected to terminals 13 and
14 of the CTB1 terminal block.
1. Adjust per recommended
settings.
2. Repair leak if necessary and add
refrigerant.
3. Change dryer/core.
4. Replace TXV.
5. Check GPM (See Limitations
in Installation section). Check
operation of pump, clean pump
strainer, purge chilled liquid
system of air.
6. Replace transducer/low pressure
switch or faulty wiring. Refer to
Service section for pressure/
voltage formula.
7. Replace LLSV.
JOHNSON CONTROLS