
Integrated Gas Control (IGC) Board
The IGC is provided on gas heat units. (See Fig. 42 and Table 25.) The IGC controls the direct spark ignition system and monitors the rollout switch, limit switch, and
RED
The IGC is equipped with an LED
48/50PG and PM
C07028
Fig. 42 − Integrated Gas Control (IGC) Board
Table 25 – IGC Connections
TERMINAL | POINT DESCRIPTION | SENSOR LOCATION | TYPE OF I/O | CONNECTION | |
LABEL | PIN NUMBER | ||||
|
|
| |||
|
| INPUTS |
|
| |
RT, C | Input power from TRAN 1 | control box | 24 VAC |
| |
SS | Speed sensor | gas section | analog input | J1, | |
FS, T1 | Flame sensor | gas section | switch input |
| |
W | Heat stage 1 | MBB | 24 VAC | J2, 2 | |
RS | Rollout switch | gas section | switch input | J2, | |
LS | Limit switch | gas section | switch input | J2, | |
CS | Centrifugal switch (not used) |
| switch input | J2, | |
|
| OUTPUTS |
|
| |
L1, CM | Induced draft combustion motor | gas section | line VAC |
| |
IFO | Indoor fan request | control box | relay | J2, 1 | |
GV (W1) | Gas valve (heat stage 1) | gas section | relay | J2, 12 | |
GV (W2) | Gas Valve (heat stage 2, from MBB) | gas section | Not on IGC |
75