Mitsubishi Electric MXZ-8B48NA Para El Instalador página 13

7. Electrical work
<Example> (In case of 2-branch boxes)
Outdoor unit
(A)
(A)
L1
L2
Circuit
GR
(C)
breaker
S1
(B)
S2
S3
(C)
Warning:
In case of A-control wiring, there is high voltage potential on the S3 terminal caused by electrical circuit design that has no electrical insulation between power
line and communication signal line. Therefore, please turn off the main power supply when servicing. And do not touch the S1, S2, S3 terminals when the power
is energized. If isolator should be used between outdoor unit and branch box/indoor unit and branch box, please use 3-pole type.
Caution:
After using the isolator, be sure to turn off and on the main power supply to reset the system. Otherwise, the outdoor unit may not be able to detect the
branch box(es) or indoor units.
#
Branch box 1
(5-branch type)
Indoor unit
TB3A
(D)
S1 S1
S2 S2
S3 S3
TB2B TB3B
(D)
S1 S1 S1
S2 S2 S2
S3 S3 S3
TB3C
(D)
S1 S1
S2 S2
S3 S3
TB3D
(D)
S1 S1
S2 S2
S3 S3
TB3E
(D)
S1 S1
S2 S2
S3 S3
Indoor unit
TB3A
(D)
S1 S1
S2 S2
S3 S3
TB3B
(D)
S1 S1
TB2B
S2 S2
S1
S3 S3
S2
S3
TB3C
(D)
S1 S1
S2 S2
S3 S3
Branch box # 2
(3-branch type)
Fig. 7-3
Power supply
Isolator (Switch)
S1
S2
Outdoor unit
S3
7.3. External wiring procedure (Fig. 7-3)
The power supply work is needed only to the outdoor unit. The power supply to the
branch box or indoor unit is conducted through wiring.
Therefore, the power supply work can be carried out at just one spot of the outdoor
unit. It will contribute to simplifying the work and saving costs.
A ROOM
E Power supply single phase AC208/230 V, 60 Hz
Max. Permissive System Impedance 0.22 (Ω)
Note:
B ROOM
1 Power supply input: Outdoor unit only.
Connect the lines (C), (D) in accordance with the terminal block names to
ensure correct polarity.
Wire diameter
C ROOM
(A) Main power (B) Ground
line
10.6 mm 2 10.6 mm
AWG7 AWG7
D ROOM
Maximum circuit ampacity
32 A
When using twisted wire for the wiring, the use of round terminal is required.
E ROOM
*1. A breaker with at least 3 mm [1/8"] contact separation in each pole shall be provided. Use
earth leakage breaker (NV).
*2. Max. 45 m (147 ft.) ("Outdoor unit - Branch box #1" plus "Branch box #1 - Branch box #2").
F ROOM Notes:
1. Wiring sizes must comply with the applicable local and national code.
2. Use wires rated 600 V or more for the power supply cables and the indoor
unit/branch box/outdoor unit connecting cables.
3. Install ground wires longer than power cables.
G ROOM
4. Use separate conduit holes for power lines (3 lines) and signal lines (4 lines) .
5. The inner diameter of a wiring conduit for the power line is required to be
more than 10.1 mm (7/16").
6. Since the distances between the fi xing positions of the grounds for the sig-
H ROOM
nal lines and the terminal blocks for the signal lines are long, the ground
wires for the signal lines are 180 - 200 mm (7-1/16" - 7-7/8") longer than the
signal lines .
7. Use copper supply wires.
IMPORTANT
Make sure that the current leakage breaker is one compatible with higher
harmonics.
Always use a current leakage breaker that is compatible with higher
harmonics as this unit is equipped with an inverter.
The use of an inadequate breaker can cause the incorrect operation of
inverter.
3 poles isolator (Switch)
S1 S1
Branch
S2 S2
box
S3 S3
(C) Signal line (D) Signal line Interrupting
current
2 1.65 mm 2 1.65 mm 2
50 A
AWG15 *2 AWG15 *2
Maximum rating of over-current protector device
52 A
S1
"A-control"
S2
Indoor unit
S3
Breaker *1
Performance
characteristic
50 A, 30 mA for
0.1 sec. or less
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