Mitsubishi Electric PAC-AK50BC Manuel D'installation page 8

9. Electrical work
<example>
(in case of 2-branch boxes)
Outdoor unit
(A) (A)
L
E
N
Circuit
(C)
breaker
S1
(B)
S2
S3
(C)
Fig. 9-5
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-poles 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.
8
#
Branch box 1
(5-branch type)
Indoor unit
TB3A
(D) A ROOM
S1 S1
S2 S2
S3 S3
TB2B TB3B
(D) B ROOM
S1 S1 S1
S2 S2 S2
S3 S3 S3
TB3C
(D)
C ROOM
S1 S1
S2 S2
S3 S3
TB3D
(D) D ROOM
S1 S1
S2 S2
S3 S3
TB3E
E ROOM
(D)
S1 S1
S2 S2
S3 S3
Indoor unit
TB3A
(D)
F ROOM
S1 S1
S2 S2
S3 S3
TB3B
G ROOM
(D)
S1 S1
TB2B
S2 S2
S1
S3 S3
S2
S3
TB3C
H ROOM
(D)
S1 S1
S2 S2
S3 S3
Branch box # 2
(3-branch type)
Power supply
Isolator (Switch)
S1
Outdoor unit S2
S3
9.2. External wiring procedure (Fig. 9-5)
E Power supply: Single phase 220/230/240 V, 50 Hz 220 V, 60 Hz
Note:
1 Power supply input: Outdoor unit only. Connect the lines (C), (D) in accord-
ance with the terminal block names to ensure correct polarity.
2 As for lines (C), S1 and S2 are for connecting the power source.
And S2 and S3 are for signals. S2 is a common cable for the power source
and signal.
Wire diameter
(A) Main (B) Earth
power line line
2 2
6.0 mm 6.0 mm
When using twisted wire for the wiring, the use of round terminal is required.
*1 Refer to the installation manual of the outdoor unit.
*2 Max 45 m ("Outdoor unit - Branch box
If 2.5 mm 2 used, Max 55 m.
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 245 IEC 57)
3. Install an earth line longer than power cables.
3 poles isolator (Switch)
S1 S1
Branch
S2 S2
box
S3 S3
(C) Signal (D) Signal Interrupting
line line current
2 2
1.5 mm *2 1.5 mm *1
# 1" plus "Branch box # 1 - Branch box
S1
"A-control"
S2
Indoor unit
S3
Breaker
Performance
characteristic
*1
# 2").