
YORK INTERNATIONAL
78
FORM 201.25-NM1 (302)
Maintenance
TROUBLESHOOTING GUIDE
PROBLEM
POSSIBLE CAUSE
ACTION
No display on panel
–
Mains supply to control system off.
Switch on mains supply if safe to do so.
unit will not operate
Emergency stop device off.
Check if control panel emergency stop switch and
any remote emergency stop devices are in the ‘OFF’
position. Turn to ‘ON’ position (1) if safe to do so.
No supply to -T3.
Check emergency stop switch fuses.
No 24VAC supply to power board.
Check wiring from -T3 to power board and fuse -F3.
No +12V output from power board.
Replace power board or isolate excessive load on
the board.
NO RUN PERM displayed
No liquid flow through the cooler.
Ensure that liquid pumps are running. Valves are
(No run permissive)
correctly set and flow is established.
Flow switch contacts are not made
Check the flow switch is functional and is installed
according to the manufacturers instructions.
Note: On some systems the pump starter may be
wired to the unit and controlled to start by the unit.
SYS # HIGH OIL TEMP
Measured temperature incorrect.
Check for blockages in condenser coils and check oil
displayed
cooler.
Check sensor calibration, location and wiring
Chiller FAULT: LOW
Ambient air temperature is lower
Use the ‘ambient temp.’ key to display the tempera
AMBIENT TEMP
than the programmed operating
ture and confirm that the displayed value is approxi
displayed
limit.
mately correct. The warning message should clear
when the ambient air temperature reaches the
programmed operating limit.
Measured temperature is incorrect.
Check the programmed settings are correct for the
options fitted to the unit.
Check sensor calibration, location and wiring.
Chiller FAULT: HIGH
Ambient air temperature is higher than the
AMBIENT TEMP
programmed operating limit.
displayed
Measured temperature is incorrect.
Use the ‘ambient temp.’ key to display the tempera-
ture and confirm that the displayed value is approxi-
mately correct. The warning message should clear
when the ambient air temperature falls below the
programmed operating limit.
Check the programmed settings are correct for the
options fitted to the unit.
Check sensor calibration, location and wiring.
Chiller FAULT: LOW
Leaving liquid drops below the
Check for restrictions in the liquid flow line.
WATER TEMP
programmed low limit faster
Check the liquid flow is stable.
displayed
than the unit can unload.
Unit is not unloading.
Check the supply to the unloader valve solenoid.
Check the compressor unloads correctly.
Measured temperature is incorrect.
Check sensor calibration, location and wiring.
Chiller FAULT: VAC
Poor mains supply voltage.
Check mains supply is stable and within allowable
UNDERVOLTAGE
limits.
displayed
Check for voltage dip on compressor start.
TABLE 8 –
TROUBLESHOOTING GUIDE