DCN: 141-00940-09 11/02/07
16
HVAC System Wiring - Standard Gas/Electric
Diagram 1 - Standard Gas or Electric System Wiring
Standard HVAC System Setup Notes:
Single Stage Systems use W1 for heating stage 1, and Y1 for cooling stage 1.
Two Stage Heating systems use W1 for stage 1 and W2 for stage 2 heating.
Two Stage Cooling systems use Y1 for stage 1 and Y2 for stage 2 cooling.
HVAC System 24VAC Transformer
If you have an integrated heating and cooling system with a single transformer,
do NOT cut jumper JP1
.
Wire the 24V Return (red) wire to either RH or RC. This is typical of most central systems.
If you have separate heating and cooling systems with separate transformers,
cut jumper JP1
. Wire the
heating 24V R (red) wire to the control unit’s RH terminal and run the cooling systems 24V R (red) wire to
control unit’s RC terminal. Also wire the cooling systems 24VAC Com to the control units 24VAC Com
terminal.
Standard HVAC System
G Fan
W1 Heat Stage 1
Y1 Comp Stage 1
R 24VAC Return
C 24VAC Common
Red
(or RH for split systems)
Green
White
Yellow
24V RC
W1 Heat
1
G Fan
Y1 Comp 1
W2 Heat 2
HVAC SYSTEM
THERMOSTAT CONNECTION
TXB16 HVAC Control Unit
Typical thermostat wiring color codes
Y2 Comp Stage 2
24V RH
IMPORTANT!
For typical central heating/cooling systems,
leave jumper JP1 installed. If you have separate Heating
and Cooling system transformers, CUT JUMPER JP1.
Wire RC to the Cooling system transformer and RH to the
Heating system transformer.
J4
Y2 Comp 2
W2 Heat Stage 2
Orange
Black
S2
STD
SW1
1
2
OFF ON
HP
Red
(or RC for split systems)
Wire R to either RH or RC for common
transformer HVAC systems
24V COM
HFRU REV P
JP1
RC&RH
FUSE
Set SW1-S1 to STD
Set SW1-S2 to OFF
Dipswitch SW1 Setup for Standard HVAC Systems
1. Set SW1-1 (position 1) to the STD position. (Off - to the left) (default setting)
2. Set SW1-2 (position 2) to the correct setting for your HVAC system.
a.
Gas furnaces
do not require fan outputs for heating calls. Set SW1-2 to the Off - to the left. (default)
b.
Electric furnaces
do require fan outputs for heating calls. Set SW1-2 to the On - to the right.
