Mitsubishi Electric PAC-MK51BCB Manuel D'installation page 11

8. Electrical work
M-NET Branch BOX
(5-branches type)
TB2B TB3A
L
S1
S2
N
S3
TB3B
S1
TB5
S2
M1
S3
M2
S
TB3C
S1
S2
S3
TB3D
S1
S2
S3
TB3E
S1
S2
S3
Fig. 8-9
A B
220/230/240 V
or
C
A B D
220/230/240 V
L N
C
TB2B
Fig. 8-10
Indoor unit
S1
A ROOM
S2
S3
S1
B ROOM
S2
S3
S1
C ROOM
S2
S3
• Recommended Connection Method
When connecting one indoor unit to the branch box, connect it to TB3A. When connecting
 indoor units, connect them to TB3A and TB3B. When connecting 3 indoor units, connect
them to TB3A, TB3B, and TB3C. Connect indoor units in the order of A→B→C→D→E.
D
or or
E C E C E
M1 M2 S L N M1 M2 S
E
TB5 TB2 TB5 TB15
Note:
Connect the lines (B), (C) in accordance with the terminal block names to
1
ensure correct polarity.
As for lines (C), S1 and S2 are for connecting the power source.
2
And S2 and S3 are for signals. S2 is common cable for the power source
and signal.
(A) Main power line/
Earth line
3-core .5 mm

When using twisted wire for the wiring, the use of round terminal is required.
Notes: 1. Wiring size must comply with the applicable local and national
code.
2. Power supply cords and indoor unit/branch box/outdoor unit con-
necting cords shall not be lighter than polychloroprene sheathed
flexible cord. (Design 60245 IEC 57)
3. Install an earth line longer than power cables.
4. Do not bundle the M-NET cable with the connection cable and
power supply cable.
It may cause erroneous operation.
Reactor BOX (Optional parts)
3
When the product is used for a purpose other than as professional equip-
ment, the Reactor BOX may be necessary.
Outdoor unit
1-phase power supply
3-phase power supply
Warning:
Never splice the cable, otherwise it may result in a smoke, a fire or communi-
cation failure.
Power supply wiring (Supply power separately to branch box
and outdoor unit)
• Install an earth line longer than other cables.
• Power supply cords of appliance shall not be lighter than design 45IEC57 or
7IEC57, 45 IEC 53 or 7 IEC 53.
• A switch with at least 3 mm, 1/8 inch contact separation in each pole shall be
provided by the air conditioner installation.
[Fig. 8-10]
Ground-fault interrupter
A
Local switch/Wiring breaker
B
Branch Box
C
Pull box
D
1 2
M-NET CONTROL INDOOR UNIT
E
Wire diameter
(B) M-NETcable Shielding (C) Signal line/
wire CVVS, CPEVS or MVVS
-core 1.5 mm 4-core 1.5 mm

Less Than 00 m Less Than 5 m
Branch box power supply method
Power supply from
Separate power supply
outdoor unit
Unnecessary Necessary
Necessary Necessary
Earth line

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