Section 12. Electrical - High Voltage - Trane 4TTR3 Installation And Operation Manual

Thermostat
24 VAC HOT
FAN
24 VAC
Common
COOL
HEATING
• Units with pigtails require wirenuts for connections. Cap all unused wires.
• In AC systems for multiple stages of heat, jumper W1 and W2 together if comfort control has only one stage of heat.
* If equipped with second stage heat
** When using a BK enabled comfort control, cut BK jumper and bypass Y and YLo at the furnace. Connect BK from comfort control to
BK of the furnace

Section 12. Electrical - High Voltage

12.1 High Voltage Power Supply
! WARNING
LIVE ELECTRICAL COMPONENTS!
During installation, testing, servicing, and
troubleshooting of this product, it may be nec-
essary to work with live electrical components.
Failure to follow all electrical safety precau-
tions when exposed to live electrical compo-
nents could result in death or serious injury.
The high voltage power supply must agree with
the equipment nameplate. Power wiring must
comply with national, state, and local codes.
Follow instructions on unit wiring diagram located
on the inside of the control box cover and in this
document included with the unit.
12.2 High Voltage Disconnect Switch
Install a separate disconnect switch at the outdoor unit.
For high voltage connections, flexible electrical conduit is recommended whenever vibration transmission may
create a noise problem within the structure.
12.3 High Voltage Ground
Ground the outdoor unit per national, state, and local code requirements.
10
With Furnace
Outdoor
Furnace
Unit
R R
G G
B/C B B
Y1 Y
Y
W1 W1
W2 W2
*
With Variable Speed Furnace
Thermostat Furnace
R R
24 VAC HOT
G G
FAN
24 VAC B/C B
Common
O
Y1 Y
COOL
**
Y
LO
W1 W1
HEATING
W2 W2
*
BK
BK
**
Outdoor
Unit
B
Y
18-AC79D1-10E-EN