Power And Communication Wiring For Systems; Outdoor Unit Diagrams - Lennox MCA Series Service Manual

11. Power and Communication Wiring for
Systems
CAUTION
This unit must be properly grounded and protected by a
circuit breaker. The ground wire for the unit must not be
connected to a gas or water pipe, a lightning conductor or
a telephone ground wire.
Do not connect power wires to the outdoor unit un-
til all other wiring and piping connections have been
completed.
Install all wiring at least 3 feet (1 m) away from televi-
sions, radios or other electronic devices in order to
avoid the possibility of interference with the unit op-
eration.
Do not install the unit near a lighting appliance that in-
cludes a ballast. The ballast may affect remote control
operation.
WARNING
Isolate the power supply before accessing unit electri-
cal terminals.
Install unit so that unit disconnect is accessible.
Follow all local and national codes, as well as this
installation instruction, during installation. Do NOT
overload electrical circuit, as this may lead to failure
and possible fire.
Use specified wiring and cable to make electrical con-
nections. Clamp cables securely and make sure that
connections are tight to avoid strain on wiring. Inse-
cure wiring connections may result in equipment fail-
ure and risk of fire. Wiring must be installed so that all
cover plates can be securely closed.
In the U.S.A., wiring must conform with current local codes
and the current National Electric Code (NEC). In Canada,
wiring must conform with current local codes and the current
Canadian Electrical Code (CEC).
Refer to unit nameplate for minimum circuit ampacity and
maximum over-current protection size.
• All indoor units are powered by the outdoor unit.
• Make all electrical power wiring connections at the
outdoor unit.
• Size outdoor unit power per local code and power
requirements.
• Connect wiring between indoor and outdoor terminals.
• Refer to unit name plate for rated voltage.
• Be sure to reattach all electrical box covers after
connections are complete.
• Follow NEC/CEC standards and all local and state
codes during wiring installation.

12. Outdoor Unit Diagrams

BLUE
BLACK
V
U W
Y/G
T4
T5 T3
Figure 22. 09 and 12K - 208/230VAC Outdoor Unit
Wiring Diagram
REACTOR
BLUE
CN 30
RED
CN 29
CN 28
BLACK
U V
W
Y/G
CN 21
T5 T3 T4
Figure 23. 12K - 115VAC Outdoor Unit Wiring
24
Y/G Y/G
BROWN
1
Y/G
Indoor Unit
Y/G
BLACK
Y/G Y/G
1
CN 3 CN 1 CN 2 CN 16
CN 1A Y/G
OUTDOOR
MAIN
PCB
CN 7
3
DC-FAN
Y/G
Diagram
BLACK
2
3
L2
L1
Y/G
2 3 L N Y/G