WLCG/WLHG
High-Wall Air Handlers
• Installation, Operation and Maintenance Manual •
P/N 240008111, Rev. G [06/18/10]
13
Electrical Wiring
(continued)
Electric heat applications
(Figure 14, Page 13)
If the indoor unit has electric heat then a “W”
connection is required between the thermo-
stat and indoor unit.
Some thermostats do not require the use of
the “C” (brown) connection.
Heat pump applications
(Figure 15, Page 13)
Heat pump operation requires the connection
of the “O” (orange) terminal from the outdoor
unit to the thermostat.
The reversing valve is energized in the cool-
ing mode for EMI models S1HG heat pump
condensers.
NOTICE
Heat pumps only
: Two-stage heating
requires the combination of a heat pump
condenser and an indoor unit that is
equipped with an electric strip heater.
The indoor electric heater will energize
as the second stage heat source (the tem-
perature is dependent on the thermostat
selected) and also during the defrost
mode for all heat pump models.
Finishing
Ensure that any unused wires are insulated
with a wire nut to prevent contact with the
junction box or other metal surfaces.
Once certain all electrical connections are
made replace control box cover.
control box
Replace screw
Wall-mounted thermostat
Figure 14
configuration —
c electric heat
Wall-mounted thermostat
Figure 15
configuration —
c heat pump
