Mitsubishi Electric PAC-AKA51BC Installation Manual page 8

9. 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.
8
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. 9-9
Power supply
Isolator (Switch)
S1
Outdoor unit
S2
S3
9.2. External wiring procedure (Fig. 9-9)
Power supply: Single phase 08 /30V, 60 Hz
E
A ROOM
Note:
Power supply input: Outdoor unit only. Connect the lines (C), (D) in accor-
1
dance with the terminal block names to ensure correct polarity.
As for lines (C), S1 and S2 are for connecting the power source.
2
B ROOM
And S2 and S3 are for signals. S2 is a common cable for the power source
and signal.
C ROOM
Wire diameter
(A) Main
(B) Ground
power line
10.6 mm² 10.6 mm²
D ROOM
[AWG 7] [AWG 7]
When using twisted wire for the wiring, the use of round terminal is required.
*1 Refer to the installation manual of the outdoor unit.
E ROOM
* Max 45 m, 147 ft. ("Outdoor unit - Branch box
box # ").
Notes: 1. Wiring size must comply with the applicable local and national
code.
2. Use copper supply wires.
F ROOM
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.
G ROOM
H ROOM
3 poles isolator (Switch)
S1 S1
Branch
S2 S2
box
S3 S3
(C) Signal (D) Signal Interrupting
line line current
1.65 mm² * 1.65 mm²
*1
[AWG 15] [AWG 15]
# 1" plus " Branch box
S1
"A-control"
S2
Indoor unit
S3
Breaker
Performance
characteristic
*1
# 1 - Branch