10
Table 3 — Main Base Board Inputs and Outputs
LEGEND
Compressor Protection Module (CPM) —
T
here
is one CPM per compressor. See Fig. 9. The device controls the
compressor contactors, oil solenoid, and loading/unloading the
solenoid. The CPM also monitors the compressor motor tem-
perature, high pressure switch, oil level switch, discharge gas
temperature, oil pressure transducer, motor current, MTA
(must trip amps) setting and economizer pressure transducer
(sizes 175,200,350,400 only). The CPM responds to com-
mands from the MBB (Main Base Board) and sends the MBB
the results of the channels it monitors via the LEN (Local
Equipment Network). The CPM has three DIP switch input
banks, Switch 1 (S1), Switch 2 (S2), and Switch 3 (S3). The
CPM board DIP switch (S1) configures the board for the type
of starter, the location and type of the current transformers and
contactor failure instructions. See Table 4 for description of
DIP switch 1 (S1) inputs. See Appendix D for DIP switch
settings.
DESCRIPTION
INPUT/OUTPUT
I/O TYPE
DISPLAY MODULE POINT NAME
CONNECTION POINT
Pin
Notation
Power (24 vac supply)
—
—
—
MBB-J1, MBB-J1A,
MBB-J1B
11
24 vac
12
Ground
Local Equipment Network
—
—
—
MBB-J9A, MBB-J9B,
MBB-J9C, MBBJ9D
+
RS485 Port (D+)
G
RS485 Port (Gnd)
-
RS485 Port (D-)
Carrier Communication
Network
—
—
—
MBB-J12
+
RS485 Port (D+)
G
RS485 Port (Gnd)
-
RS485 Port (D-)
Chilled Water Flow Switch
CWFS
Switch
Cooler Flow Switch,
LOCK
MBB-J5B-CH17
17
Demand Limit Switch No. 1
Demand Limit SW1
Switch
Limit Switch 1 Status,
DLS1
MBB-J4-CH13
Condenser Flow Switch
CDFS
Switch
Condenser Flow Switch,
COND
16A
MBB-J5A-CH16A
Circuit A Discharge
Pressure Transducer
DPTA
Pressure Transducer
Discharge Pressure,
DP.A
MBB-J7A-CH6
5V
+5 vdc Ref.
S
Signal
R
Return
Circuit B Discharge
Pressure Transducer
DPTB
Pressure Transducer
Discharge Pressure,
DP.B
MBB-J7C-CH8
5V
+5 vdc Ref.
S
Signal
R
Return
Dual Chiller
LWT Thermistor
DUAL
5k Thermistor
CHWS Temperature,
CHWS
MBB-J6-CH3
Dual Set Point Input
Dual Set Point
Switch
Remote Setpoint Switch,
DUAL
MBB-J4-CH12
Heat/Cool Switch
HC_SW
Switch
Heat/Cool Select Contact,
HC_SW
MBB-J4-CH14
Entering Water Thermistor
EWT
5k Thermistor
Cooler Entering Fluid,
EWT
MBB-J6-CH2
Leaving Water Thermistor
LWT
5k Thermistor
Cooler Leaving Fluid,
LWT
MBB-J6-CH1
Condenser Entering Water
Thermistor
CEWT
5k Thermistor
Condenser Entering Fluid,
CEWT
MBB-J6-CH5
Condenser Leaving Water
Thermistor
CLWT
5k Thermistor
Condenser Leaving Fluid,
CLWT
MBB-J6-CH4
External Chilled
Water Pump Interlock
PMPI
Switch
Electrical Box Interlock,
ELEC
MBB-J4-CH15A
Circuit A Suction
Pressure Transducer
SPTA
Pressure Transducer
Suction Pressure,
SP.A
MBB-J7B-CH7
5V
+5 vdc Ref.
S
Signal
R
Return
Circuit B Suction
Pressure Transducer
SPTB
Pressure Transducer
Suction Pressure,
SP.B
MBB-J7D-CH9
5V
+5 vdc Ref.
S
Signal
R
Return
Unit Status
Remote Contact-Off-Enable
Switch
On/Off Remote Switch,
ONOF
MBB-J4-CH11
Alarm Relay
ALM R
Relay
Alarm Relay Output,
ALRM
MBB-J3-CH24
Alert Relay
ALT R
Relay
Alert Relay Output,
ALRT
MBB-J3-CH25
Cooler Pump Relay 1
PMP1
Contactor
Cooler Pump 1,
CPUMP_1
MBB-J2A-CH19
Cooler Pump Relay 2
PMP2
Contactor
Cooler Pump 2,
CPUMP_2
MBB-J2A-CH20
Condenser Pump Relay
CPMP
Contactor
Condenser Pump,
COND_PMP
MBB-J2C-CH22
Pump #1 Interlock
Pump #2 Interlock
PMP_1
PMP_2
Switch
Cooler Pump Run Status,
PUMP
MBB-J5C-CH18
I/O
—
Input or Output
LWT —
Leaving Water Temperature