YORK YK — LCSSS - Phase loss

The control center shows LCSSS - Phase loss; some manuals print it in capitals as LCSSS - PHASE LOSS. It belongs to the liquid cooled solid state starter (LCSSS) message group listed for this chiller on the OptiView™ control center.

The LCSSS logic/trigger board has detected that the line-to-line RMS voltage in any phase has decreased to less than or equal to 30% of the lowest value of the programmed voltage range — in other words, any one of the three phases of input line voltage has dropped below the threshold value. The manual treats this message as a cycling shutdown. If the programmed voltage range is disabled, a value of 60 VAC is used as the threshold; for a 440-480 VAC range the manual gives 132 VAC as the example.

• A supply disturbance — the manual notes that many times this is a normal fault related to a storm or lightning.
• One of the three phases of input voltage absent; the manual points out that an input fuse may be open.
• An improper voltage range selected on the OptiView™ control center.

• Shutdown threshold: line-to-line RMS voltage in any phase at or below 30% of the lowest value of the programmed voltage range.
• If the programmed voltage range is disabled, the threshold is 60 VAC.
• Manual example: 132 VAC for the 440-480 VAC range.

This shutdown clears itself — the manual describes no separate reset step. The chiller automatically restarts when the line voltage is greater than the shutdown threshold; as a cycling shutdown it is an automatic restart after coastdown if the shutdown is no longer active and the compressor switch is still in the run position.