York YK-EP Operation And Maintenance Manual page 254

Motor Communications Protocol (VSD applications (VSD and Style B LCSSS applications)
Only displayed when Motor Drive Type setpoint above is selected as "VSD-60Hz", "VSD-50Hz" or
"SSS-Mod B". Allows the Service technician to enable the appropriate serial communications port
for communications with the Style B Liquid Cooled Solid State Starter (LCSSS) or Variable Speed
Drive (VSD). Early vintage Style B LCSSS and VSD communicate with the microboard using YORK
protocol (COM 5 (J15)). Later vintage units use Modbus protocol (COM 2 (J13)).
The protocol selection enables the appropriate communications port:
• YORK enables COM 5 A(J15)
• Modbus enables COM 2 (J13)
Selection required is based on the hardware and interface that is present. The chiller must be
stopped with the START-RUN-STOP/RESET switch in the STOP/RESET position to change this
setpoint. A description of the two protocols is as follows:
YORK – Enables COM 5 (J15) serial port. On Variable Speed Drive applications, used when
1.
the microboard is interfaced to the VSD via the ACC Board. On Style B Liquid Cooled Solid
State Starter applications, used when the microboard is interfaced to the LCSSS Logic/Trigger
Board TB2.
2. Modbus – Enables COM 2 (J13) serial port.
- VSD Applications – Used when the ACC Board is not present and the microboard is
interfaced directly to VSD Logic Board 031- 02506 (J16).
- Style B Solid State Starter Applications – Used when the microboard is interfaced to
the LCSSS Logic/Trigger Board 031-02505 (J14).
Motor Node ID (VSD and Style B Liquid Cooled Solid State Starter applications).
Only displayed when Modbus is selected for the Motor Communications Protocol setpoint. Allows
the Service technician to enter the Modbus Address of the VSD logic board or Style B LCSSS Logic/
Trigger Board. The Motor Node ID setpoint must match the Modbus Address assigned to these
boards. Whenever the microboard is reading or writing to these devices, it transmits the address
entered as the Motor Node ID setpoint. The device will only respond if the transmitted address
matches the address assigned to the device. The chiller must be stopped to change this setpoint.
VSD Applications – Enter 1 for the Motor Node ID setpoint. Then set the Modbus Address
•
of VSD Logic Board 031-02506 to "1" by setting Switch SW3 position 1 to ON with all other
positions OFF.
Style B Solid State Starter Applications – Enter 1 for the Motor Node ID setpoint. Then set the
•
Mod-bus Address of the Logic/Trigger Board 031-02505 to 1 by setting Switch SW1 Position 1
to ON with all other positions OFF.
Coastdown Time – Only appears when STANDARD is selected for the Coastdown setpoint. Sets the
duration of the coastdown period. The time is programmable over the range of 240 (default) to 900
seconds or 150 (default) to 900 seconds as determined by the selection made for the Chiller Style/
Compressor setpoint on the OPERATIONS Screen. Refer to the Chiller Style/Compressor setpoint.
Condenser Temperature Range – Special order chillers that operate at higher than standard
condenser temperatures require higher condenser high pressure warning and safety thresholds.
This setpoint allows the software to be used in either standard or high temperature applications.
254 YK-EP Style B Centrifugal Chiller