Lennox T7300 Installation Instructions Manual page 3

WIRE
WALL OPENING
SHADED AREA
Figure 6 − Restrict Wires to Shaded Area of Wire
Terminal
Designation
Rc (see note 1) Power for cooling−connect to secondary side of cooling system transformer.
R (see note 1) Power for heating−connect to secondary side of heating system transformer.
Y Compressor output.
C (see note 2) Command wire from secondary side of cooling system transformer.
W Heat relay.
G Fan relay.
W2 Second stage heat relay.
Y2 Second stage cooling.
O/B (see note 3) Changeover valve for heat pumps. Terminal not used with Lennox commercial equipment.
A (see note 4) Economizer/Time−of−Day (TOD) output−powered via R terminal.
S1 (see note 5) Optional outdoor or indoor remote sensor.
S2 (see note 5) Optional outdoor or indoor remote sensor.
L Powers red LED behind plastic in upper right corner of the thermostat.
NOTES:
1. When used in a single−transformer system, leave
metal jumper wire in place between Rc and R. If
used on a two−transform system, remove metal
jumper wire between Rc and R.
2. Common wire is optional when thermostat is used
with batteries. When using separate transformer
for heating and cooling, the common must come
from the cooling transformer.
3. Lennox commercial heat pumps do not use this
terminal to energize
Thermostat will always be conventional type.
4. Reference economizer literature for wiring details.
When set for economizer operation, the A terminal
provides the occupancy signal. (Power indicates
occupied.)
5. Sensor wires must have a cable separate from the
thermostat control cable.
WALLPLATE
Hole
Table 2 − Terminal Designation Descriptions
the reversing
Description
Terminal
Economizers
− Wire the A" terminal as shown in diagrams in
figures 7, 8, 9 and 10.
− The A" signal is powered from the R" terminal and
energizes the economizer to signal occupied status
and drive the damper to the set minimum position.
valve.
Page 3
A Wiring Details for