York YK Style H Operation Manual page 187

transducer (system low pressure) and the output of the Pump Oil Pressure transducer (system high
pressure). The chiller can be started after the differential oil pressure decreases to less than 90.0
PSID and the Clear Fault key is pressed on the display.
Oil – Pump Pressure Transducer Out Of Range
The Pump Oil Pressure transducer (system high pressure) is indicating a pressure that is less than
0.0 PSIG or greater than 315.0 PSIG. This is outside the normal operating range of the transducer.
This generally indicates a defective transducer. The chiller can be started after the transducer is
indicating a pressure that is within range and the Clear Fault key is pressed on the display.
Oil – Sump Pressure Transducer Out Of Range
The Sump Oil Pressure transducer (system low pressure) is indicating a pressure that is outside the
normal operating range of the transducer as follows:
• R-134a is less than 0.0 PSIG or more than 315.0 PSIG.
This generally indicates a defective transducer. The chiller can be started after the transducer is
indicating a pressure that is within range and the Clear Fault key is pressed on the display.
Oil – Differential Pressure Calibration
The Sump and Pump oil pressure transducers indicated a differential oil pressure of greater than
15.0 PSID during the oil pressure transducer Auto-Zeroing period that begins 10 seconds into
System Prelube and lasts for 3 seconds. This is indicative of a defective Sump or Pump transducer,
since the oil pump is not running during this period and the actual differential oil pressure is 0
PSID. The transducers are sensing the same pressure during this period and their outputs should
be similar. The chiller can be started after the Clear Fault key is pressed on the display.
Oil – Variable Speed Pump – Setpoint Not Achieved
This is only applicable to chillers equipped with the Variable Speed Oil Pump Drive. One of the
following conditions have occurred while in System Prelube, System Run or System Coastdown. The
chiller can be started after the Clear Fault key is pressed on the display.
• The differential oil pressure was less than 35.0 PSID for 5 continuous seconds during the last
10 seconds of the System Prelube period or during the first 15 seconds of System Run.
OR
• Anytime after the first 30 seconds of System Run, the differential oil pressure was less than
the Oil Pressure Setpoint with the speed command from the Microboard at 60 Hz for 5
continuous seconds.
Control Panel – Power Failure
A Control Power failure has occurred. If the power failure duration was less than the duration of
the applicable coastdown period (2.5 minutes standard; 15 minutes steam turbine), the remainder
of the coastdown is performed upon restoration of power. The chiller can be started after the
Clear Fault key is pressed on the display. This message can indicate a Cycling (autorestart after
power failure) or Safety (manual restart after power failure) shutdown, depending upon Control
Center configuration. It indicates a cycling shutdown when displayed in orange characters; safety
shutdown when displayed in red characters. The Control Center is configured for auto-restart
or manual restart after power failure by a qualified Service Technician following instructions in
OptiView Control Center – Service Instructions (Form 160.76-M1).
Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center 187