Trane 4TTX8024A Installer's Manual page 15

Variable Speed Furnace
Hook-up Diagram
Comfort Control
Red
R
Y1 Yellow
Brown
Y2
Green
G
White
W1
Black
W2
Blue
B
18-AC95D1-1
Neatly bundle all low voltage
wires behind the service
valve cover as shown.
Variable Speed
Furnace
R
O
Y
LO
Yellow
Y
BK
G
W1
W2
B
Air Conditioner
Yellow/Black
Brown
Yellow/Red
Blue
Notes:
1. Installer must cut the
factory R to BK jumper
on furnace circuit board.
OR, on new 15-digit
models, set the S5-2
DIP switch to OFF.
2. Installer must add a
field installed jumper
between R and O on the
furnace terminal strip
3. 4TTX8 units require
80% airflow with Y1 (low
stage) and 100% airflow
with Y2 (high stage).
A) Connect Y1 from
comfort control to
Y at the VS furnace
and to Y1 (yellow/
black) at the AC.
B) Connect Y2 from
comfort control to
BK at the VS furnace
and to Y2 (yellow/
red) at the AC.
4. Comfort control may not
have W2 or W3 termi-
nals.
Blue
5. If single stage heating
comfort control is used,
jumper W1 to W2 on the
furnace terminal strip.
15