York YK-EP B Operation & Maintenance Manual page 173

FORM 160.87-OM1
ISSUE DATE: 8/24/2018
less than 8 feet, it will be necessary to correct the
flow problem or add a booster pump as is applied
on retrofit chillers.
VSD – Invalid Current Scale Selection
Since the part number of the VSD Logic Board is the
same on all horsepower sizes, the position of Program
Jumpers tells the Logic Board the size of the VSD
employed. This allows the VSD to properly scale the
output current. If the jumper configuration is invalid, a
shutdown is performed and this message is generated.
Refer to Variable Speed Drive – Service Instructions
(Form 160.00-M1).
VSD – Low Phase A Inverter Heatsink
Temperature
(Style D VSD)
A heatsink temperature sensor indicating a temperature
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 transmit-
ter. The normal transmitter resistance is 10K ohms at
77°F.
VSD – Low Phase B Inverter Heatsink
Temperature
(Style D VSD)
See Low Phase A Inverter Heatsink Temperature mes-
sage above.
VSD – Low Phase C Inverter Heatsink
Temperature
(Style D VSD)
See Low Phase A Inverter Heatsink Temperature mes-
sage above.
VSD – Low Converter Heatsink Temperature
If VSD part number is 371-02767-XXX (60 Hz) or
371-03700-XXX (50 Hz), a heatsink temperature sen-
sor indicating a temperature of less than 37°F will
cause the chiller to shutdown and display this message.
In most cases, the problem will be an open transmitter
or broken wiring to the transmitter. The normal trans-
mitter resistance is 10K ohms at 77°F.
VSD – Low Phase A Inverter Baseplate
Temperature
(VSD part number 371-03789-xxx (503 HP 60 Hz; 419
HP 50 Hz)
The chiller has shutdown because the baseplate tem-
perature has decreased to less than 37°F.
JOHNSON CONTROLS
SECTION 3 - DISPLAY MESSAGES
VSD – Low Phase B Inverter Baseplate
Temperature
(VSD part number 371-03789-xxx (503 HP 60 Hz; 419
HP 50 Hz)
The chiller has shutdown because the baseplate tem-
perature 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 tem-
perature has decreased to less than 37°F.
VSD – Precharge – Low DC Bus Voltage
During pre-charge, the DC link must be equal to or great-
er 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 per-
formed 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 sec-
onds) 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 temper-
ature 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 prob-
lem 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 re-
ceived by the VSD Logic Board within 5 seconds, a
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