Unit installation

53
Table 20 – Central Terminal Board (CTB) Connections
CONNECTION LA-
BEL
PIN NUMBER POINT DESCRIPTION 24Vac FROM 24V ac TO
DDC
T’STA T
7 Cool 1 Call MBB ECON
6 Cool 2 Call MBB ECON
5 Heat Stage 1 Call MBB CONTL BOARD
4 Heat Stage 2 Call MBB CONTL BOARD
3 IGC Fan Input MBB CONTL BOARD
ECON
1,2 Cool 1 Call jumper DDC T’STAT CLO1/COMP1
3,4 Cool 2 Call jumper DDC T’STAT CLO2/COMP2
CL O1/
COMP1
3 Comp 1 Contactor Common CTB C C1 --- Coil
4,5 Comp 1 jumper ECON CIRCUIT 1 LPS
6 Comp 1 Contactor Signal CIRCUIT 1 HPS C1 --- Coil
CL O2/
COMP2
2 Loader Common CTB C Comp. Loader
3 OFMC Common CTB C O F M C --- B R N
4,5 Loader jumper ECON CIRCUIT 2 LPS
6 Loader Contactor Signal CIRCUIT 2 HPS Comp. Loader
7 ODF High Speed Signal ECON O F M C --- Y E L
CIRCUIT 1
HPS Comp 1 High Pressure Switch CIRCUIT 1 LPS CLO1/COMP1
LPS Comp 1 jumper CLO1/COMP1 CIRCUIT 1 HPS
CIRCUIT 2
HPS Loader jumper CIRCUIT 2 LPS CLO2/COMP2
LPS Loader jumper CLO2/COMP2 CIRCUIT 2 HPS
CONTRL
BOARD
2 Heat Stage 2 Call DDC T’STAT Gas Valve or PL3
3 Heat Stage 1 Call DDC T’STAT I G C --- W o r P L 3
4 IGC Common/Ground CTB C IGC C
5 Transformer 1 Common/Ground TRAN1 Common CTB C
6 IGC Call for Indoor fan IGC IFO CONTL BOARD
7 IGC Call for Indoor fan/Fan feedback CONTL BOARD MBB
8 IG C power (T1J9) CTB R IGC R
9 Transformer1Power(T1J1) TRAN1 24Vac UNIT SHUTDOWN
10 Limit Switch signal (T1J9) LSM CTB R
11 Limit Switch source (T1J8) PMR Fan overload
PMR
1 Ground CTB C PMR Device
2 Phase Monitor Source (T1J6) UN IT SHUTDOWN PMR Device
3 Phase Monitor Normally Closed Signal (T1J7) PMR Device CONTL BOARD
UNIT
SHUTDOWN
REMOTE
SHUTDOWN
Remote Disable Switch if installed (T1J4 and T1J5) SMOKE SHUTDOWN PMR
SMOKE
SHUTDOWN
Normally Closed Smoke Detector Contact (T1J3) Smoke Detector REMOTE SHUTDOWN
24V OUT Smoke Detector Controller Power (T1J2) CONTL BOARD Smoke Detector
C Smoke Detector Controller Common CTB C Smoke Detector
R Spades Transformer1PowerafterSafetyChain(T1J9) CONTL BOARD
C Spades Ground CONTL BOARD
The References above for T1J1 through T1J9 are to show the path of transformer 1 as is goes through the board and safety devices.
48/50LC