Download York YCAL0134 Technical data

8- 2
035L02465-GB0 (07/01)
PROBLEM
POSSIBLE CAUSE
ACTION
SYS X HIGH DSCH PRES
displayed
Discharge pressure cut-out
incorrectly set.
Adjust in accordance with recommended setting.
Poor airflow through the condenser
coils.
Check for airflow restrictions caused by blockages on
intake faces of air coils. Check for damaged fins.
Condenser fans not operating or
operating backwards.
Check fan motor, fuses, and contactors. Check fan
airflow is upward.
Air in refrigerant system.
Check for non-condensables (air) in system. Evacuate
and recharge system.
Excessive refrigerant charge.
Remove refrigerant.
Measured pressure is incorrect.
Check discharge transducer calibration and wiring.
Suction pressure cut-out incorrectly
set.
Adjust in accordance with recommended setting.
Faulty expansion valve (TXV).
Replace valve
Reduced cooler performance.
Check for restricted chilled liquid flow. Check for fouled
tube surfaces.
Low refrigerant charge.
Check for leaks.
Restricted refrigerant flow.
Check for blocked filter/drier.
Check -YLLSV is operating correctly
Check for moisture in the system.
Measured pressure incorrect.
Check suction pressure transducer calibration/pressure
switch and wiring.
Compressor internal motor protector
(MP) open.
Verify refrigerant charge is not low. Verify superheat
setting of 5.6° - 8.3°C. Verify correct compressor
rotation. Verify compressor is not over loaded.
External overload tripped.
Determine cause and reset.
-FHP switch open.
See 'High Discharge Pressure Fault'.
Defective -FHP switch.
Replace -FHP switch.
Defective -K1 relay.
Replace relay.
SYS X LOW SUCT PRESS
displayed
SYS X MP/HPCO FAULT
displayed
No motor cooling.
Compressor(s) do not start
Lack of cooling effect
!! LOW BATTERY !! CHECK
PROG / SETP / OPTN displayed
Demand not sufficient.
No problem.
Defective water temperature sensor.
Compare the display with a thermometer. Should be
within +/- 2 degrees. Refer to BECT/ BLCT calibration
charts.
Contactor/Overload failure.
Replace defective part.
Compressor failure.
Diagnose cause of failure and replace.
Fouled cooler surface. (Low suction
pressure will be observed).
Contact the local York service representative.
Improper flow through the cooler
Reduce flow to within unit design specification.
Low refrigerant charge. (Low
suction pressure will be observed).
Check subcooling and add charge as needed.
Check for leaks.
RTC battery (U17) flat.
Replace U17 and reprogram setpoints, values, options,
time and schedule.