Main Base Board (Mbb) - Carrier 48/50PD05 User Manual

Main Base Board (MBB)

See Fig. 16 and Table 19. The MBB is the center of the
ComfortLink 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.
The MBB also receives the Current Sensor inputs for compressors
and other discrete or digital inputs. The MBB reads space
RED LED - STATUS
J1 J2
J3
J4
J5
J6
J7
GREEN LED -
LEN (LOCAL EQUIPMENT NETWORK)
CEPL130346-01
STATUS
LEN
CCN
Fig. 16 - - Main Base Board (MBB)
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.
IMPORTANT: 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
47
J10
J9
C07026