8
9. Electrical work
Branch box
#
2
(3-branch type)
<example>
(in case of 2-branch boxes)
L1
L2
GR
S1
S2
S3
S1
S2
S3
S1
S2
S3
S1
S2
S3
TB3A
S1
S2
S3
S1
S2
S3
TB3B
TB2B
S1
S2
S3
S1
S2
S3
TB3C
S1
S2
S3
S1
S2
S3
TB3D
S1
S2
S3
S1
S2
S3
TB3E
(A)
(A)
(B)
S1
S2
S3
S1
S2
S3
TB3A
S1
S2
S3
S1
S2
S3
S1
S2
S3
TB3B
S1
S2
S3
S1
S2
S3
TB3C
(D)
(D)
(D)
(D)
(D)
(D)
(D)
(D)
(C)
A ROOM
Branch box
#
1
(5-branch type)
Outdoor unit
Indoor unit
Circuit
breaker
E ROOM
B ROOM
C ROOM
D ROOM
F ROOM
G ROOM
H ROOM
Indoor unit
TB2B
(C)
S1
S2
S3
S1
S2
S3
S1
S2
S3
S1
S2
S3
Power supply
Outdoor unit
Isolator (Switch)
3 poles isolator (Switch)
“A-control”
Indoor unit
Branch
box
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.
9.2. External wiring procedure (Fig. 9-9)
E
Power supply: Single phase 08 /30V, 60 Hz
Note:
1
Power supply input: Outdoor unit only. Connect the lines (C), (D) in accor
-
dance 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
Breaker
(A) Main
power line (B) Ground
(C) Signal
line
(D) Signal
line
Interrupting
current
Performance
characteristic
10.6 mm²
[AWG 7]
10.6 mm²
[AWG 7]
1.65 mm² *
[AWG 15]
1.65 mm²
[AWG 15]
*1
*1
When using twisted wire for the wiring, the use of round terminal is required.
*1 Refer to the installation manual of the outdoor unit.
* Max 45 m, 147 ft. (“Outdoor unit - Branch box
#
1” plus “ Branch box
#
1 - Branch
box
#
”).
Notes: 1. Wiring size must comply with the applicable local and national
code.
2. Use copper supply wires.
3. Use wires rated 600 V or more for the power supply cables and the
Indoor unit / Branch box / Outdoor unit connecting cables.
4. Install an earth longer than other cables.
Fig. 9-9
