Carrier /50HC 04-28, Controls, Start-Up, Operation And Troubleshooting, Page: 80 / 144

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Integrated Gas Control (IGC) Board
The IGC is provided on gas heat units. (See Fig. 34 and Table 31.)
The IGC controls the direct spark ignition system and monitors
the rollout switch, limit switch, and induced-draft motor Hall Ef-
fect switch.
Fig. 34 — Integrated Gas Control (IGC) Board
Table 31 — Integrated Gas Control (IGC) Board Connections
TERMINAL LABEL POINT DESCRIPTION SENSOR LOCATION TYPE OF I/O
CONNECTION PIN
NUMBER
INPUTS
RT, C
Power for IDR on 575v units control box 24 VAC Spade
C Input power common Spade
SS Speed sensor gas section analog input J1, 1- 3
FS, T1 Flame sensor gas section switch input Spade
W Heat stage 1 Call MBB to CTB to IGC 24 VAC J2, 2
G Indoor Fan Call CTB to IGC 24 VAC J2, 3
R Input power from TRAN 1 CTB to IGC 24 VAC J2, 4
RS Rollout switch gas section switch input J2, 5-6
LS Limit switch gas section switch input J2, 7-8
CS Centrifugal switch (not used) switch input J2, 9-10
OUTPUTS
L1, CM
Induced draft combustion motor or relay 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 CTB) gas section Not on IGC
RED LED- S TATU S