York YK-EP Operation And Maintenance Manual page 206

The chiller has shutdown because the baseplate temperature has decreased to less than 37°F.
VSD – Low Phase B Inverter Baseplate Temperature
The chiller has shutdown because the baseplate temperature has decreased to less than 37°F.
VSD – Low Phase C Inverter Baseplate Temperature
(VSD part number 371-03789-xxx (503 HP 60 Hz; 419 HP 50 Hz))
The chiller has shutdown because the baseplate temperature has decreased to less than 37°F.
VSD – Precharge – Low DC Bus Voltage
During pre-charge, the DC link must be equal to or greater than 50VDC (41VDC for 50 Hz) within ½
second and 500VDC within 15 seconds after the pre-charge relay is energized. If this condition is
not met, a shutdown is performed and this message is generated.
VSD – Precharge – Low DC Bus Voltage
(575V/60 Hz applications)
If the DC Link Voltage does not reach at least 60VDC (within 4 seconds) or at least 600VDC (within 20
seconds) after the precharge command has been received, this shutdown is performed.
VSD – Low Inverter Baseplate Temperature
(Applicable to VSD with part number 371-02767-XXX (60 Hz) or 371-03700-XXX (50 Hz))
A baseplate temperature sensor indicating a temperature of less than 37°F will cause the chiller
to shut down and display this message. In most cases, the problem will be an open transmitter or
broken wiring to the transmitter. The normal transmitter resistance is 5K ohms at 77°F.
VSD – Logic Board Processor
This shutdown is generated if a communications problem occurs between the two microprocessors
on the VSD Logic Board.
VSD – Run Signal
Redundant Run Signals are generated by the Control Center; one via TB6-24 and the second via
the serial communications link. Upon receipt of either of the two Run Commands by the VSD, a
5 second timer will commence timing. If both Run Commands are not received by the VSD Logic
Board within 5 seconds, a shutdown is performed and this message is displayed. This is generally
indicative of a wiring problem between the Control Center and the VSD.
VSD – Serial Communications
This message is generated when communications between the Control Center Microboard and the
VSD Logic Board is disrupted. This is generally indicative of defective wiring.
Harmonic Filter – Logic Board or Communications
This message is generated when communications between the Harmonic Filter and the VSD Logic
Board is disrupted. The communications must be interrupted for 10 continuous communications
cycles (20 seconds) before the shutdown will occur.
Harmonic Filter – High DC Bus Voltage
The Harmonic Filter's DC Link Voltage is continuously monitored and if the level exceeds 860VDC,
this shutdown is performed. The Harmonic Filter has its own DC bus as part of the filter power
assembly, and this DC Link is not connected in any way with the VSD's DC link. If this shutdown
occurs, it will be necessary to look at the level of 460VAC applied to the Harmonic Filter. The
specified voltage range is 414 to 508. If the incoming voltage is in excess of 508, steps should be
taken to reduce the level to within specified limits. The cause of this message is typically high line
voltage or a surge on the utility supply.
206 YK-EP Style B Centrifugal Chiller