Vsd - High Phase A (Or B, C) Instantaneous Current; Vsd - Initialization Failed; Vsd - Invalid Current Scale Selection; Vsd - Logic Board Power Supply - York VSD 270 Operation Manual

TABLE 4 - CYCLING SHUTDOWN MESSAGE (CONT'D)
MESSAGE
VSD - High Phase A (or B, C)
Instantaneous Current
PHASE A (OR B, C)
OVERCURRENT FAULT

VSD - Initialization Failed

VSD INITIALIZATION FAILED
VSD - Invalid Current Scale
Selection
INVALID CURRENT SCALE FAULT
VSD - Logic Board Power
Supply
MAIN BOARD POWER
SUPPLY

VSD - Logic Board Processor

PWM COMMUNICATIONS FAULT
VSD - Low Converter
Heatsink Temperature
LOW CONV HEATSINK TEMP.

VSD - Low DC Bus Voltage

LOW DC BUS VOLTAGE FLT
JOHNSON CONTROLS
This shutdown is generated by the OSCD logic board. If any one phase of motor
current as measured by the Output Current Transformers exceeds a threshold.
Refer to the chart below for the shutdown threshold value.
DRIVE HP RATING
270/292/351/424
385/419/503/608
658/704
900
If an Instantaneous Current Fault occurs but the chiller restarts and runs without a
problem, the cause may be attributed to a voltage sag on the utility power feeding
the OSCD that is in excess of the specified dip voltage rating for this product. This
is especially true if the chiller was running at, or near, full load. If there is a sudden
dip in line voltage, the current to the motor will increase. The chiller vanes cannot
close quickly enough to correct for this sudden increase in current and the chiller
will trip on this fault.
At power-up, the OSCD logic board will go through a process called initialization. At
this time, memory locations are cleared, jumper positions are checked, and com-
munications links are established between the OSCD logic board, and the Control
Center.
The J1 connector on the OSCD logic board contains jumpers along with wires from
the output CTs. The jumpers configure the OSCD logic board to the HP rating of
the OSCD being used in this application in order to properly scale the output cur-
rent. If the jumper configuration is found by the logic board to be invalid, the system
will be shut down and the above message will be generated. The proper jumper
configuration is shown on the wiring label for the OSCD.
This shutdown is generated by the OSCD logic board, and it indicates that one of
the low voltage power supplies for the OSCD logic board has dropped below their
allowable operating limits. The power supplies for the logic boards are derived from
the secondary of the 120 to 24 VAC transformer which in turn is derived from the
480 to 120 VAC control transformer.
This shutdown is generated by the OSCD logic board. If a communications
problem occurs between the two microprocessors on the OSCD logic board this
shutdown will occur.
A thermistor sensor is located on the SCR/Diode block side of the copper chill plate
on the OSCD Power Unit. Anytime this thermistor detects a temperature of 37°F
(3°C) or lower a shutdown will occur.
If the line voltage were to quickly drop the current seen by the motor could exceed
it's rating. The low bus voltage shutdown will prevent this from happening. The
shutdown is generated when the DC link voltage drops below 500 VDC for 460
VAC input voltage, 414 VDC for 380, 400, and 415 VAC input voltage or 600 VDC
for 575 VAC input voltage.
DESCRIPTION
THRESHOLD SHUTDOWN VALUE
771 AMPS PEAK
1200 AMPS PEAK
1890 AMPS PEAK
2750 AMPS PEAK
FORM 160.00-O4
ISSUE DATE: 12/19/2017
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