York YK-EP, Operation And Maintenance Manual

Page: 215 / 268

Motor – High Bearing Temperature
This safety shutdown occurs when either of the enabled motor bearing temperatures exceeds the
programmed High Bearing Temperature Shutdown threshold for 3 continuous seconds. The value
programmed for this safety threshold is displayed as High Bearing Temperature Shutdown on the
MOTOR SETPOINTS Screen. It is programmed with the Bearing Setup Setpoint on that screen. The
chiller can be started after both bearing temperatures decrease to at least 9°F below the shutdown
threshold and the Operator presses the WARNING RESET button. This safety shutdown will not
occur when the Bearing Temperature Protection Setpoint is set to Disabled on the MOTOR DETAILS
Screen. Also, it will not act on any RTD input registering as an open RTD.
Motor – High Bearing Vibration
Either the Shaft End or Opposite Shaft End motor bearing vibration has exceeded the value
programmed for the High Vibration Shutdown Setpoint for the programmed number of delay
seconds. This safety shutdown does not occur when the Motor Vibration Protection Setpoint is set
to Disabled on the MOTOR DETAILS Screen or while the WARNING – MOTOR – BEARING VIBRATION
BASELINE NOT SET warning is displayed. The chiller can be started after both vibration values
decrease below the shutdown threshold and Operator presses the WARNING RESET button.
Motor – Cooling Coil Leak
The Motor Cooling Coil Leak Detector has registered a fault condition for at least 3 continuous
seconds. The Motor Cooling Coil leak Protection Setpoint enables the type of sensor employed: If
an optical sensor is being used, the input to the Motor Monitoring Board goes high to indicate a
leak; if a float switch is used, the input goes low to indicate a leak. This safety shutdown will not
occur when the Motor Cooling Coil Leak Protection Setpoint is set to Disabled. The chiller can be
started after the leak sensor no longer indicates a leak and the Operator presses the WARNING
RESET button.
Mod “B” SSS safety shutdown messages
LCSSS Shutdown – Requesting Fault Data
The Liquid Cooled Solid State Starter Logic/Trigger Board has shut down the chiller but the Control
Center has not yet received the cause of the fault from the LCSSS, via the serial communications
link. The LCSSS shuts down the chiller by opening the Motor Controller LCSSS Stop Contacts (K1
relay located on the Logic/Trigger Board and connected between TB6-16 and TB6-53 in the Control
Center). The Microboard, in the Control Center, then sends a request for the cause of the fault
to the Logic/Trigger Board over the serial communications link. Since serial communications are
initiated every 2 seconds, this message is typically displayed for a few seconds and then replaced
with one of the following fault messages.
LCSSS – High Instantaneous Current
The Liquid Cooled Solid State Starter Logic/Trigger Board detected that the compressor motor
current in any phase exceeded 1.1(1.414 x RMS value of the programmed Start Current) for a
minimum of 1 second. The chiller can be started after the Operator presses the WARNING RESET
button.
LCSSS – High Phase (X) Heatsink Temperature – Running
The Liquid Cooled Solid State Starter Logic/Trigger Board has detected the temperature of phase
A, B or C (designed as X in the message) Silicon Controlled Rectifier (SCR) Modules has exceeded
212°F while the chiller was running. The safety can be reset after all SCR temperatures are less than
210°F and the Operator presses the WARNING RESET button. However, the chiller cannot be started
215 YK-EP Style B Centrifugal Chiller