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SECTION 4 - MICROBOARD 031-02430-000 AND 031-02430-001
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
4
Power Failure Restart –
Determines the course of ac-
tion required to restart the chiller, if a power failure
occurs while the chiller is running. Selections are:
1.
Manual –
Requires a manual reset after power is
restored. The chiller cannot be started until the
operator moves the keypad Start-Run-Stop/Reset
rocker switch to the stop/reset position.
2.
Auto –
Chiller will automatically restart when
power is restored.
Coastdown –
Determines the “Coastdown” duration
(oil pump run duration after shutdown) and whether
the “Motor Controller – Loss of Current” check and
anti-recycle function is performed while the chiller is
running. Selections are:
1.
Standard –
Electric motor applications. With
software version C.OPT.01.14.306 (and earlier),
when STANDARD is selected, the coastdown
duration is 150 seconds. With software version
C.OPT.01.16.307 (and later), when STANDARD
is selected, the Coastdown Time setpoint ap-
pears. (See
). This
setpoint is used to set the duration 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).
2.
Enhanced –
“Coastdown” is 15 minutes in dura-
tion. Steam Turbine applications. “Motor Con-
troller - Loss of Current” check and anti-recycle
function is not performed since there is no motor
current.
Pre-run –
Determines the duration of the “System Pre-
lube” period. Selections are:
1.
Standard
– “System Pre-lube” is 50 seconds in
duration.
2.
Extended
– “System Pre-lube” is 180 seconds in
duration.
Oil Pump Package –
Configures the program for ei-
ther Variable Speed Drive Oil Pump or Fixed Speed
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 tempera-
ture 50°F above condenser saturation temperature)
and the Oil Return and Liquid Line (J compressors
only) solenoid valves are connected in parallel 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
– Software version C.OPT.01.16.307 or later). (Style B
Liquid Cooled Solid State Starter applications – Soft-
ware version C.OPT.01.18.307 or later).
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 (J15)
• Modbus enables COM 2 (J13)
Selection required is based on the hardware and inter-
to determine which hardware/
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 description
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
