Carrier 48HC 04-28 - Page 78

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Table 29 — Main Base Board (MBB) Connections
DISPLAY NAME POINT DESCRIPTION SENSOR LOCATION TYPE OF I/O
CONNECTION PIN
NUMBER
INPUTS
Input power from TRAN2 control box 24 VAC J1, 1-3
IGC.F IGC Fan Request gas section switch input J6, 4
FDWN Fire shutdown switch supply/return/space switch input J6, 6
G Thermostat G (Fan) space switch input J7, 2
W2 Thermostat W2 (2nd Stage Heat) space switch input J7, 4
W1 Thermostat W1 (1st Stage Heat) space switch input J7, 6
Y2 Thermostat Y2 (2nd Stage Cool) space switch input J7, 8
Y1 Thermostat Y1 (1st Stage Cool) space switch input J7, 10
FIL.S Filter status switch indoor fan section switch input J9, 2-3
HUM Humidistat switch input space switch input J9, 5-6
Not Used 0-5vdc digital input J9, 7-9
Not Used 0-5vdc digital input J9, 10-12
SPT Space temperature (T55/56) space 10k thermistor J8, 1-2
SPTO Space temperature offset (T56) space 10k thermistor J8, 2-3
OAT Outdoor air temperature outdoor coil support 10k thermistor J8, 5-6
SAT Supply air temperature
indoor fan housing, or
supply duct
10k thermistor J8, 7-8
SCT.A
Saturated condenser temperature,
circuit A
outdoor coil, circuit A 5k thermistor J8, 9-10
SCT.B
Saturated condenser temperature,
circuit B
outdoor coil, circuit B 5k thermistor J8, 11-12
RAT Return Air
Temperature
Return 10k thermistor J8, 13-14
FAN.S Fan status
switch
indoor fan section switch input J8, 15-16
SSP.A Suction pressure, circuit A compressor A suction pipe
0-5 VDC pressure
transducer
J8, 18-20
SSP.B Suction pressure, circuit B compressor B suction pipe
0-5 VDC pressure
transducer
J8, 21-23
Not Used 0-5 VDC J8, 24-26
OUTPUTS
CRC Cooling Reheat Control relay J10, 3
RH2.A Reheat 2 Valve Circuit A relay J10, 6
RH2.B Reheat 2 Valve circuit B relay J10, 9
IDF.1 Indoor fan relay 1 relay J10, 11
IDF.2 Indoor Fan relay 2 relay J10, 13
IDF.3 Indoor Fan relay 3 relay J10, 16
ALRM Alarm relay relay J10, 19
COMP.B Compressor B1 relay relay J10, 21
COMP.A Compressor A1 relay relay J10, 23
HT.1 Heat Stage 2 relay relay J10, 25
HT.2 Heat Stage 1 relay relay J10, 27
COMMUNICATION
Local Equipment Network (LEN) communication J5, 1-3
Carrier Comfort Network (CCN) communication J5, 5-7
Network device power 24 VAC J5, 9-10
Scrolling Marquee Display (LEN) communication J4, 1-3
Scrolling Marquee Display power 24 VAC J4, 5-6
Expansion LEN Bus communication J3, 1-3
Optional ECB power 24 VAC J2, 1-2