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SECTION 5 - MICROBOARD 031-03630-001
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
5
Oil Pump. Chillers equipped with the Variable Speed
Drive Oil Pump have a Program controlled Oil Heater
and a different complement of solenoid valves than
chillers equipped with a Fixed Speed Oil Pump. A de-
scription of the two Oil Pumps is as follows:
1.
Variable Speed
(style D and later) – configures the
program to operate the Variable Speed Drive Oil
Pump, the Oil Heater (maintains oil temperature
50°F above condenser saturation temperature)
and the Oil Return and Liquid Line (J compres-
sors only) solenoid valves are connected in paral-
lel to TB1-61.
2.
Fixed Speed
(style C) – Configures the program to
operate the fixed speed Oil Pump and the follow-
ing solenoid valves:
• TB1-34 Liquid Line
• TB1-61 Oil Return and Vent Line connected
in parallel
• TB1-62 High Speed Thrust
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 commu-
nications 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 commu-
nications port:
• YORK enables COM 5 (J1A 5)
• Modbus enables COM 2 (J13)
Selection required is based on the hardware and inter-
SECTION 14 - ADAPTIVE CAPACITY
Board to determine which hard-
ware/interface is present. The chiller must be stopped
with the START-RUN-STOP/RESET switch in the
STOP/RESET position to change this setpoint. A de-
scription of the two protocols is as follows:
1.
YORK
– Enables COM 5 (J15) serial port. On
Variable Speed Drive applications, used when 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 Sol-
id State Starter applications).
Only displayed when Modbus is selected for the Mo-
tor 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 transmit-
ted address matches the address assigned to the device.
The chiller must be stopped with the START-RUN-
STOP/RESET switch in the STOP/RESET position 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 dura-
tion of the coastdown period. The time is programma-
ble over the range of 240 (default) to 900 seconds or
150 (default) to 900 seconds as determined by the se-
lection made for the Chiller Style/Compressor setpoint
on the OPERATIONS Screen. Refer to the Chiller
Style/Compressor setpoint.