Main Base Board (Mbb) - Carrier 48/50PG C03-14 Operation And Service Manual

Main Base Board (MBB)

See Fig. 40 and Table 23. The MBB is the center of the
ComfortLinkt control system. It contains the major portion of the
operating software and controls the operation of the unit. The
MBB continuously monitors input/output channel information
received from its inputs and from the Economizer Control Board
(ECB). The MBB receives inputs from thermistors and transducers.
RED LED - STATUS
CEPL130346-01
J1 J2
J3
J4
J5
J6
J7
GREEN LED -
LEN (LOCAL EQUIPMENT NETWORK)
STATUS
LEN
CCN
Fig. 40 − Main Base Board (MBB)
The MBB also receives the Current Sensor inputs for compressors
and other discrete or digital inputs. The MBB reads space
temperature (SPT) from either a T-55, T-56 or T-58 device and
space temperature offset (SPTO) from a T-56 device. See
Field-Installed Accessories section. The MBB controls 9 relays.
NOTE: The Main Base Board (MBB) has a 3-position instance
jumper that is factory set to '1.' Do not change this setting.
YELLOW LED -
CCN (CARRIER COMFORT NETWORK)
INSTANCE JUMPER (SET TO 1)
J8
71
J10
J9