System Requirements; Wiring - Carrier 40MBD-06SI Installation Instructions Manual

SYSTEM REQUIREMENTS

Allow sufficient space for airflow and servicing unit. See Fig. 3 for
minimum required distances between the unit and the walls or
ceilings.
Piping
IMPORTANT: Both refrigerant lines must be insulated
separately.
S Minimum refrigerant line length between the indoor and outdoor
units is 10 ft. (3 m).
S Table 3 lists the pipe sizes for the indoor unit. Refer to the
outdoor unit installation instructions for other allowed piping
lengths and refrigerant information.
Table 3—Piping Lengths
9K
Gas Pipe
In 3/8
(size-connection
(mm) (9.52)
type)
Liquid Pipe
In 1/4
(size-connection
(mm) (6.35)
type)
12K 18K 24K 36K 48K
1/2 1/2 5/8 5/8 5/8
(12.7) (12.7) (16) (16) (16)
1/4 1/4 3/8 3/8 3/8
(6.35) (6.35) (9.52) (9.52) (9.52)

WIRING

All wires must be sized per NEC (National Electrical Code) or
CEC (Canadian Electrical Code) and local codes. Use the
Electrical Data table MCA (minimum circuit amps) and MOCP
(maximum over current protection) to correctly size the wires and
the disconnect fuse or breakers respectively.
Per caution note, only stranded copper conductors with a 600 volt
rating and double insulated copper wire must be used. The use of
BX cable is not recommended.
Recommended Connection Method for Power and
Communication Wiring − Power and Communication Wiring:
The main power is supplied to the outdoor unit. The field
supplied 14/3 power/communication wiring from the outdoor unit
to the indoor unit consists of four (4) wires and provides the
power for the indoor unit. Two wires are high voltage AC power,
one is communication wiring and the other is a ground wire.
Recommended Connection Method for Power and
Communication Wiring (To minimize communication wiring
interference) Power Wiring:
The main power is supplied to the outdoor unit. The field
supplied power wiring from the outdoor unit to the indoor unit
consists of three (3) wires and provides the power for the indoor
unit. Two wires are high voltage AC power and one is a ground
wire.
To minimize voltage drop, the factory recommended wire size is
14/2 stranded with a ground.
Communication Wiring:
A separate shielded stranded copper conductor only, with a 600
volt rating and double insulated copper wire, must be used as the
communication wire from the outdoor unit to the indoor unit.
Please use a separate shielded 16GA stranded control wire.
CAUTION
!
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution may result in equipment
damage or improper operation.
S Wires should be sized based on NEC and local codes.
S Use copper conductors only with a 600 volt rating and
double insulated copper wire.
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