Carrier WEATHERMASTER 48/50Z030-105 - Manual (Page 117)

117
CONTROL EXPANSION MODULE (CEM) — The optional
CEM is used to provide inputs for demand limiting, remote set
point and other optional inputs typically needed for energy
management systems. See Fig. 29. On CCN systems these
inputs can be interfaced to through the CCN communications.
It is located in the main control box. The CEM also has inputs
for accessory relative humidity sensors. This board is also used
on units equipped with optional outdoor air CFM monitoring.
The inputs and outputs are summarized in Table 91.
The optional (or accessory) CEM is used to accept inputs
for additional sensors or control sequence switches, including:
• Smoke control mode field switches
• VAV supply air set point reset using an external 4 to
20 mA signal
• Outdoor air CO
2
sensor
• Space, return and/or outdoor air relative humidity
sensors
• IAQ function discrete switch
• Demand limit sequence proportional signals or discrete
switches
The CEM is factory-installed when the outdoor air cfm con-
trol option is installed.
LOW VOLTAGE TERMINAL STRIP — This circuit board
provides a connection point between the major control boards
and a majority of the field-installed accessories. See Table 92.
The circuit breakers for the low voltage control transformers,
interface connection for the Carrier Comfort Network ® (CCN)
communication, and interface connection for the Local Equip-
ment Network (LEN) communication are also located on the
low voltage terminal strip.
INTEGRATED GAS CONTROL (IGC) — One IGC is pro-
vided with each bank of gas heat exchangers. One is used on
low heat size 030-050 units. Two are used on high heat size
030-050 units and low heat 055-105 units. Three are used on
high heat 055-105 units. The IGC controls the direct spark ig-
nition system and monitors the rollout switch, limit switches,
and induced-draft motor Hall Effect switch. The IGC is
equipped with an LED (light-emitting diode) for diagnostics.
See Table 93.
COMPRESSOR PROTECTION BOARD (CSB) (Size 105
Units Only) — This board monitors the status of the compres-
sor by sensing the current flow to the compressors and then
provides digital status signal to the MBB.
ADDRESS DIP
SWITCHES ALL ON RED LED-
STATUS GREEN LED-
LEN (LOCAL EQUIPMENT NETWORK)
J2 J1
PWR
J4
LEN LEN
J3
4-POSITION
DIP SWITCH
PWR
1
13
10
7
XDCR/THERM
4
1
J6
J5
7 4 1 3 1 3 1
J8
0-20mA OUT
J7
THERM XDCR/THERM
1
4
13
10
7
RELA
YS
J9
CEBD430427 HK50AA032 CEPL130427
Fig. 28 — Staged Gas Heat Control Board (SCB)