York YK-EP Operation And Maintenance Manual page 216

until all SCR temperatures are less than 109°F. During the shutdown, the starter cooling pump runs
until the temperature is less than 109°F.
LCSSS – 105% Motor Current Overload
The highest phase of the compressor motor current increased to greater than 105% of the
programmed 100% chiller Full Load Amps continuously for 40 seconds. The chiller can be started
after the Operator presses the WARNING RESET button.
LCSSS – Phase (X) Shorted SCR
A shorted Silicon Controlled Rectifier (SCR) in phase A, B or C (designated as X in the message) has
been detected by the Liquid Cooled Solid State Starter Logic/Trigger Board. The voltage across each
SCR in monitored to detect the shorted condition. The shorted condition must exist continuously
for 5 seconds in order to annunciate the fault. This check is disabled while the chiller is running.
The chiller can be started after the condition has been corrected and the Operator presses the
WARNING RESET button.
LCSSS – Open SCR
An open Silicon Controlled Rectifier (SCR) has been detected by the Liquid Cooled Solid State
Starter Logic/Trigger Board. The open condition must exist continuously for 5 seconds in order
to annunciate the fault. The chiller can be started after the condition has been corrected and the
Operator presses the WARNING RESET button. This check is disabled when the chiller is shut down.
In certain applications, local power line conditions could interfere with the open SCR detection
technique. This requires a qualified Service Technician to disable this check. Refer to OptiView
Control Center – Service Instructions (Form 160.54-M1).
LCSSS – Phase (X) Open SCR
An open SCR in phase A, B or C (designated as X in message) has been detected. This safety
shutdown has the same criteria as LCSSS – OPEN SCR above, however, the phase in which the open
SCR occurred is identified.
LCSSS – Phase Rotation
The Liquid Cooled Solid State Starter Logic/Trigger Board has detected the three phase compressor
motor power line voltage phase rotation is not correct. The chiller can be started after the phase
rotation is correct and the Operator presses the WARNING RESET button.
Compressor motor VSD safety shutdown messages
The following safety shutdown messages are displayed on Compressor Motor Variable Speed
Drive (VSD) applications only. These messages are generated by events that occur within the
VSD. The chiller can be started after manual resets are performed as detailed below. Service and
troubleshooting information is contained in Variable Speed Drive – Service Instructions (Form 160.00-
M1).
VSD Shutdown – Requesting Fault Data
The VSD has shut down the chiller and the Control Center has not yet received the cause of the
fault from the VSD, via the serial communications link. The VSD shuts down the chiller by opening
the Motor Controller VSD Stop Contacts (located on the VSD Logic 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 VSD Logic Board via the Adaptive Capacity Control Board,
over the serial 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.
216 YK-EP Style B Centrifugal Chiller