FORM 150.75-NM2
97
YORK INTERNATIONAL
PROBLEM
CAUSE
SOLUTION
“HIGH DSCH” Fault
1. Condenser fans not operating or rotating backwards.
1. Check fans, fuses, and contactors.
Cuts out on High Discharge
2. Too much refrigerant.
2. Remove refrigerant.
Pressure as sensed by
3. Air in Refrigerant System.
3. Evacuate and recharge.
Microprocessor via high
4. Defective discharge pressure transducer.
4. Replace discharge pressure transducer.
discharge pressure transducer.
5. Assure Programmable H.P. Cut-out is correctly set. 5. Adjust per recommended settings and restart unit.
6. Assure OAT sensor is reading properly.
6. Place a thermometer next to the sensor and compare
NOTE: If external H.P. Cut-out
reading to the display. Operation should not suffer if
Switch opens, a “Motor
thermometer is +/- 10°F.
Current” Fault will result.
“CHILLER FAULT:
1. Temperature sensed incorrectly by thermistor.
1. Verify actual ambient temperature at probe +/-10°F
HIGH AMBIENT TEMP”
with a thermometer placed next to the OAT sensor.
Cuts out on high ambient
2. Fans rotating backwards.
2. Air flow must be up. Correct fan rotation.
temperature.
3. Air flow to unit restricted (or being re-circulated).
3. Check installation clearances.
(Max. = 130°F will re-start
(See Page 9).
automatically if temperature
4. High ambient cut-out set too low.
4. Reprogram cut-out.
drops below 128°F)
“CHILLER FAULT:
1. Temperature of outside air is below cut-out setting. 1. No problem exists.
LOW AMBIENT TEMP”
2. Temperature sensed incorrectly by thermistor.
2. Verify actual ambient temperature immediately
Cuts out on low ambient
at probe with thermometer.
temperature.
3. Check low ambient temperature
3. Adjust if necessary.
(25°F min. for std. adjustable
for low ambient unit)
NOTE: For occasional operation below 0°F set the cut-out
at 0°F. The chiller is then allowed to operate regardless of
NOTE: Operation below 25°F
temperature. A low ambient kit must be installed.
requires low ambient accessory.
CHILLER FAULT:
1. RWT Control ONLY: Control range is too small and
1. Flow is lower than design. Increase flow or increase the
LOW WATER TEMP
does not match actual
D
T across evaporator under
control range to match actual evaporator
D
T.
Low water temperature
full load conditions.
shutdown
2. Check LWT cut-out point on panel.
2. Adjust if necessary and restart unit.(See Page 46).
3. Defective LWT or RWT sensor.
3. Check according to following table (use digital volt meter)*
(Assure the sensor is properly installed in the
Replace if necessary.
bottom of the well with a generous amount of heat
conductive compound.)
TEMP.
VOLTAGE (DC)
20.0°F
1.65
NOTE: It is not unusual to find up to a +/- 2°F
22.0°F
1.71
difference between the display and a thermometer
25.0°F
1.82
located in water piping.
27.0°F
1.88
30.0°F
1.99
33.0°F
2.09
36.0°F
2.22
38.0°F
2.28
41.0°F
2.37
43.0°F
2.43
46.0°F
2.54
48.0°F
2.60
50.0°F
2.67
* Check voltage on
53.0°F
2.77
Microprocessor Board.
55.0°F
2.83
57.0°F
2.89
LWT: J11-7 to J11-1
59.0°F
2.95
RWT: J11-8 to J11-1
61.0°F
3.02
63.0°F
3.08
65.0°F
3.14
67.0°F
3.20
70.0°F
3.28
