Mod B Solid State Starter 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 Clear Fault key is pressed on the display.
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 Clear Fault key is pressed on the display.. However, the chiller cannot be started 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 Clear Fault key is pressed on the display.
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 Clear Fault key is pressed on
the display.
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
Compressor Switch is placed in the Stop-Reset (O) position. 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 160.76-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, when the Solid State Starter
is equipped with Eprom version C.SSS.01.03 (and later) the phase in which the open SCR occurred is
identified.
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Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center
