49
FORM 160.54-M1
ISSUE DATE: 10/25/2019
JOHNSON CONTROLS
JCI COMPANY CONFIDENTIAL
4
DESCRIPTION
Microboard 031-02430-000 is supplied in new pro-
duction chillers from January 2004 to June 2006 (See
). Although this board uses a
different microprocessor and supporting components,
chiller control and operator interface are the same as
the previous 031-01730-000 Microboard. It uses the
same mounting hole pattern and has the same interface
connectors as the previous board, making it backward
compatible to all previous YK OptiView Control Cen-
ters equipped with the 031-01730-000 Microboard.
After June 2006, new production YK chillers will be
supplied with Microboard 03102430-001. This board is
an upgraded version of the 031-02430-000 Microboard.
Its physical dimensions, mounting and connections
are the same as the 031-02430-000 Microboard. It is
backward compatible to existing YK chillers using the
031-01730-000 or 031-02430-000 Microboards and is
supplied as service replacement for these boards in kit
331-02430-601. The upgrade includes a larger BRAM
(U38) and an additional RS-485 port on COM2 serial
port (J13) for Modbus serial communications protocol
to Variable Speed Drives. The details of the differences
between the -000 board and -001 board are described in
the respective areas of this section. These upgrades are
necessary for the following applications that require
RS-485 Modbus communications to the microboard:
• Medium Voltage Solid State Starter (MV SSS)
and Medium Voltage Variable Speed Drive (MV
VSD).
• New production Variable Speed Drives (VSD) af-
ter March 2007. With the VSD Modbus applica-
tions, the Adaptive Capacity Control (ACC) func-
tionality is contained in the microboard and the
ACC Board is not used.
• New production Style B LCSSS after mid 2008.
The board is supplied with +12 VDC (J1-3), -12 VDC
(J1-4), +5 VDC (J1-1) and ground (J1-2) from the
Power Supply (See
). The -12
VDC is not used. The +5 VDC (fused by F1) can be
monitored at TP3. It is applied to a +3.3 VDC regula-
tor, +2.5 VDC regulator and used directly by the mi-
croboard circuits as the Vcc voltage. The outputs of
these regulators are applied to Microboard circuits and
can be monitored at TP2 and TP5 respectively. The
+12 VDC (fused by F2) can be monitored at TP4. It
is applied to a +5 VDC regulator and used directly by
Microboard circuits. The output of the regulator is the
+5 VDC (analog) supply that powers all analog circuits
and is the source voltage for all transducers and therm-
istors. It can be monitored at TP10 as a 2.5 VDC value
created by 1K Ohm resistors voltage divider circuit as
shown.
Test Points
The power supply voltages can be measured at follow-
ing test points: (See
)
• TP1 GND
• TP2 +3.3 VDC
• TP3 +5 VDC
• TP4 +12 VDC
• TP5 +2.5 VDC
• TP10 +2.5 VDC
Boot-up Program
The BIOS (Basic Input Output System) EPROM (U37)
contains the boot-up program. The YORK part number
is 031-02429-001 and is used in both the 031-02430-
000 and 031-02430-001 Microboards. It is available
from the Baltimore Parts Distribution Center as a re-
placement part. The version is an alphanumeric code
that identifies the application and the program revision
level. The part number and version are printed on a la-
bel adhered to the surface of the EPROM. It is also
displayed on the DIAGNOSTICS Screen in SERVICE
access level.
The version is as follows:
C. OPT. 00. NN.
Revision level. Increments 01, 02 etc.
BIOS EPROM
OptiView Control Cente
r
Commercial chiller
SECTION 4 - MICROBOARD 031-02430-000 AND 031-02430-001
