YORK YK — Thrust bearing - Proximity probe out of range

The panel shows Thrust bearing - Proximity probe out of range. The manual lists the message under the safety fault messages. The event is listed on the Systems Details Screen, where a Clear button sits next to it, and the manual notes that the fault acknowledge for this fault is on the System Details Screen.

The message means that the clearance between the compressor high speed thrust collar and the tip of the proximity probe has decreased to less than 18 ml. Detection is not continuous: the manual states the clearance is only checked during the last 20 s of system prelube, during system run and during coastdown, and the fault is only detected during those periods. The message applies only to compressors that use proximity thrust bearing protection. The fault itself is released when the high speed thrust bearing proximity position is at least 18 ml.

• The clearance between the compressor high speed thrust collar and the tip of the proximity probe has decreased to less than 18 ml.

1. Before the chiller is started, the shutdown has to be evaluated first. The manual's CAUTION applies: a qualified service technician must evaluate this shutdown before starting.
2. The service technician checks the proximity position against the reference position. Restart is inhibited until the clearance is within +10 ml to -25 ml of the reference position.
3. The service technician performs the special reset procedure required before restart, then clears the message as described under Reset.

• Trip threshold: the message appears when the clearance between the compressor high speed thrust collar and the tip of the proximity probe has decreased to less than 18 ml.
• Release threshold: the fault is released when the high speed thrust bearing proximity position is at least 18 ml.
• Detection windows: the last 20 s of system prelube, during system run and during coastdown.
• Restart band: the clearance must be within +10 ml to -25 ml of the reference position before restart is allowed.

To release the message, place the compressor switch in the stop position and press the Clear button next to the listed event on the Systems Details Screen. Before the Clear button is pressed, the fault must be acknowledged on the Proximity Probe Calibration Screen, and a special password is required for that. Clearing the message alone does not restore restart: the chiller stays inhibited until the clearance is within +10 ml to -25 ml of the reference position and the special reset procedure has been performed by the service technician.