88 YORK INTERNATIONAL
PROBLEM CAUSE SOLUTION
Low Suction Fault 1. Improper Suction Pressure Cut-out 1. Adjust per recommended settings and
adjustment. restart unit.
2. Low refrig. charge. 2. Repair leak/add refrigerant.
3. Fouled filter drier. 3. Change drier core.
4. Thermal expansion valve adjust- 4. Adjust compressor suction superheat to
ment/failure. 11°F (6.1°C) or replace power element
(or valve).
5. Reduced flow of chilled liquid through 5. Check GPM (See OPERATING
cooler. LIMITATIONS) Check operation
of pump. Clean pump strainer,
purge chilled liquid
system of air.
6. Defective suction press. transducer. 6. Replace transducer.
7. Fouled compressor suction strainer. 7. Remove and clean strainer.
8. Faulty wiring to transducer. 8. Check wiring.
High Dsch Fault 1. Condenser fans not operating or 1. Check fans, fuses and contactors.
Cuts out on High rotating backwards.
Discharge Pressure as 2. Too much refrigerant. 2. Remove refrigerant.
sensed by 3. Air in Refrigerant System. 3. Evacuate and recharge.
Microprocessor via 4. Defective discharge pressure 4. Replace discharge pressure transducer.
high discharge transducer.
pressure transducer. 5. Assure Programmable H.P. Cut-out is 5. Adjust per recommended settings and
NOTE: If external H.P. correctly set. restart unit.
Cut-out Switch opens, 6. Assure OAT sensor is reading properly. 6. Place a thermometer next to the sensor
a Motor Current Fault and compare reading to the display.
will result. Operation should not suffer if thermometer
is +10°F.
Chiller Fault: High 1. Temperature sensed incorrectly by 1. Verify actual ambient temperature at
Ambient Temp thermistor. probe +10°F with a thermometer placed
Cuts out on high ambi- next to the OAT sensor.
ent temperature. 2. Fans rotating backwards. 2. Air flow must be up. Correct fan rotation.
(Max. = 130°F will 3. Air flow to unit restricted (or being 3. Check installation clearances.
restart automatically if re-circulated). (See Page 8).
temperature drops 4. High ambient cut-out set too low. 4. Reprogram cut-out.
below 128°F)
Chiller Fault: Low 1. Temperature of outside air is below 1. No problem exists.
Ambient Temp cutout setting.
Cuts out on low
ambient temperature. 2. Temperature sensed incorrectly by 2. Verify actual ambient temperature
(25°F min. for std. thermistor. immediately at probe with thermometer.
adjustable for low
ambient unit) 3. Check low ambient temperature 3. Adjust if necessary.
NOTE: Operation Cut-out setting on the display. NOTE: For occasional operation below
below 25°F 0°F, set the cut-out at 0°F. The
requires low chiller is then allowed to operate
ambient accessory. regardless of temperature. A low
ambient kit must be installed.
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