WLCG/WLHG
High-Wall Air Handlers
• Installation, Operation and Maintenance Manual •
P/N 240008111, Rev. G [06/18/10]
11
Electrical Wiring
(continued)
Units with or without heat
NOTICE
All low voltage interconnect wiring must
be at least 18 AWG.
Cooling-only
Cooling only units utilize two low volt in-
terconnecting wires between the indoor and
outdoor units.
Wires designated “Y” (yellow) and “C”
(brown) of the air handler should be con-
nected to the corresponding “Y” (yellow)
and “C” (brown) wires or terminals of the
condenser (Figure 11, Page 11).
Other wires or terminals such as “R” (red) or
“O” (orange) may not be needed and should
be protected by a wire nut from making
contact with the junction box or other metal
surfaces.
Heat pump connection
Heat Pump Connection: In addition to the
“Y” and “C” connections required for cooling,
heat pumps require a reversing valve control
wire “O” (orange) that is energized in the
cooling mode.
If the indoor unit has an electric heater, then
a ”W” (white) wire connection will also be
needed to energize the indoor electric heat.
If a wall thermostat is used.
Heat pumps models require an “R” connec-
tion between the indoor and outdoor unit to
provide power to the defrost control board in
the condenser (Figure 12, Page 11).
Unit-mounted controls —
Figure 11
cooling only
Unit-mounted controls —
Figure 12
heat pump connection, two-
stage heating
