York YD Mod D, Operation Manual, Page: 142 / 160

Table 143: Safety shutdown messages
Message Description
DISCHARGE #1 – VALVE
NOT OPENED
The chiller (both compressors) has shutdown because compressor #1 Discharge Valve did
not fully open (as indicated by the closure of the valve opened end switch) within 40 seconds
of receiving the open command. The chiller can be started after the valve “opened” end
switch closes for 3 seconds, compressor #1 is stopped, and the Operator presses the Clear
Faults button. This prevents the possibility of initiating a fault due to switch bounce.
DISCHARGE #2 – VALVE
NOT OPENED
The chiller (both compressors) has shutdown because compressor #2 Discharge Valve did
not fully open (as indicated by the closure of the valve opened end switch) within 40 seconds
of receiving the open command. The chiller can be started after the valve “opened” end
switch closes for 3 seconds, compressor #2 is stopped, and the Operator presses the Clear
Faults button. This prevents the possibility of initiating a fault due to switch bounce.
AUXILIARY SAFETY –
CONTACTS CLOSED
The chiller (both compressors) has shutdown because locally installed external safety
shutdown contacts connected to I/O Board TB4-31 have closed, initiating a safety shutdown.
The chiller can be started after the contacts have opened and the Operator presses the Clear
Faults button.
OIL – HIGH TEMPERATURE The chiller (both compressors) has shutdown because the oil temperature, as sensed by
thermistor RT3, has increased to >180.0 ºF. The chiller can be started after the temperature
decreases to <180.0 ºF. The chiller can be started after the contacts have opened and the
Operator presses the Clear Faults button.
OIL PUMP #1 –
DIFFERENTIAL PRESSURE
CALIBRATION
The chiller (both compressors) has shutdown because the Sump oil pressure transducer and
compressor #1 Pump oil pressure transducer indicated a differential pressure of >15.0 PSID
during the oil pressure transducer auto-zeroing period that begins 10 seconds into “System
Prelube” and lasts for 3 seconds. This safety only applies when compressor #1 is the lead
compressor. This is indicative of a defective Sump or Pump transducer, since the transducers
are sensing the same pressures during this period. The chiller can be started after the Clear
Faults button is pressed.
If compressor #1 is locked-out using the Lockout key on the Capacity Compressor Cycling
Screen, this fault does not cause compressor #2 to shutdown or prevent it from starting.
When this fault occurs on a locked- out compressor, it is displayed as a warning. This allows
the user to know that a fault exists be corrected prior to the lockout being removed from the
compressor. If it is not, the warning condition will revert back to a shutdown as soon as the
lockout is removed and will cause the chiller to trip.
OIL PUMP #2 –
DIFFERENTIAL PRESSURE
CALIBRATION
The chiller (both compressors) has shutdown because the Sump oil pressure transducer and
compressor #2 Pump oil pressure transducer indicated a differential pressure of >15.0 PSID
during the oil pressure transducer auto-zeroing period that begins 10 seconds into “System
Prelube” and lasts for 3 seconds. This fault only applies when compressor #2 is the lead
compressor. This is indicative of a defective Sump or Pump transducer, since the transducers
are sensing the same pressures during this period. The chiller can be started after the Clear
Faults button is pressed.
If compressor #2 is locked out using the Lockout key on the Capacity Compressor Cycling
Screen, this fault does not cause compressor #1 to shutdown or prevent it from starting.
When this fault occurs on a locked-out compressor, it is displayed as a warning. This allows
the user to know that a fault exists on the locked-out compressor. The condition must be
corrected prior to the lockout being removed from the compressor. If it is not, the warning
condition will revert back to a shutdown as soon as the lockout is removed and will cause the
chiller to trip.
OIL PUMP #1 – HIGH
DIFFERENTIAL PRESSURE
The chiller (both compressors) has shutdown because the oil pressure differential, as sensed
by compressor #1 Pump transducer and the Sump transducer, has increased to >90.0
PSID. This fault is only checked if both the compressor #1 Pump transducer and the Sump
transducer are in range. The chiller can be started after the differential is <90.0 PSID and the
Operator presses the Clear Faults button.
OIL PUMP #2 – HIGH
DIFFERENTIAL PRESSURE
The chiller (both compressors) has shutdown because the oil pressure differential, as sensed
by compressor #2 Pump transducer and the Sump transducer, has increased to >90.0
PSID. This fault is only checked if both the compressor #2 Pump transducer and the Sump
transducer are in range. The chiller can be started after the differential is <90.0 PSID and the
Operator presses the Clear Faults button.
Model YD Mod D with OptiView Control Center 142