York YK Style H Operation Manual page 174

Leaving Chilled Liquid – Flow Switch Open
The Chilled Liquid Flow Switch has remained open for 5 continuous seconds while the chiller was
running or failed to close during the System Prelube period. The chiller will automatically restart
when the flow switch closes.
While this cycling shutdown is active, the evaporator pump relay contacts (TB2-44/45) remain
closed un-til the chiller is given a stop command or has another fault. With all previous software
versions, these contacts open at completion of coastdown.
Motor Controller – Contacts Open
The CM-2 Current Module (Electromechanical starter applications) has shutdown the chiller. When
detecting a fault condition that places the starter or motor at risk, these devices open the Motor
Controller contacts "CM" (located on the respective device and con-nected between TB6-16 and
TB6-53 in the Control Center) to initiate a shutdown.
Since there are several different faults that are monitored, LED's on the respective device illuminate
to identify the specific fault that has occurred. Refer to OptiView Control Center – Service Instructions
(Form 160.76-M1) for CM-2 initiated shutdowns. The chiller will automatically restart when the
Motor Controller contacts close. On some shutdowns, the respective device automatically closes
the contacts when the fault condition clears. Other shutdowns require the Operator to perform a
Manual Reset at the respective device.
Table 176: CM-2 faults
Device
CM-2 Module
Motor Controller – Loss Of Current
The Compressor Motor current decreased to 10% Full Load Amps (FLA) for 25 continuous seconds
while the chiller was running. This could be caused by the starter de-energizing during run or a
defect in the motor current feedback circuitry to the Control Center. The chiller will automatically
restart at the completion of System Coastdown.
Power Fault
The CM-2 Current Module (Electromechanical Starter applications) has shut down the chiller
because it detected a fault condition that places the motor at risk. These devices open and close
the Motor Controller "CM" contacts located in the CM-2 and connected between TB6-16 and TB6-53
in the Control Center in less than 3 seconds to initiate the shutdown and produce this message.
An LED on the CM-2 illuminates to identify the specific fault that has occurred. Refer to OptiView
Control Center – Service Instructions (Form 160.76-M1) for CM-2 initiated shutdowns. The chiller will
automatically restart when the contacts close.
Table 177: CM-2 shutdown
Device Shutdown
CM-2 Module Power Fault
Proximity Probe – Low Supply Voltage
(Chillers with J or H3 compressors).
This message indicates the +24 VDC power supply voltage to the Proximity Probe has decreased
to +19.0 VDC. This is below the minimum level required for reliable operation. The chiller will
automatically restart when the voltage increases to greater than or equal to 19.7 VDC.
174
Manual reset fault
Overload
Overload
Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center
Automatic reset fault
None
Phase Rotation/Loss