Mitsubishi Electric MXZ-8B48NA Manual De Instalación página 13

7. Electrical work
<Example> (In case of 2-branch boxes)
Branch boxM
(5-branchtype)
[-- ..... TB3A--I D , F_ln-d°°rLnit
Outdoor unit , _,l-t_;! f:_1 I A ROOM
rq ! _/
....... _i :_t
® _ _bl I
Circuit ' ' r_CG-_l t C, it TB2B TB3B I F-_-_-_
breaker I I_l p q L_ d£-1 i -(D_, ' £1% B ROOM
i ____,, , _ , ___'___ =
_--i cROOM
IE °ROOM
II :
,-4q-- D I--=_=:-I
(C) I I I'_ I E ROOM
i.... @ i
'-11-
_', _1
IL ....... ,
I I .......... Indoor unit
i i TB3A I ,_, I-- ....
I I I FROOM
IL :
I I TB3B I r-- ....
I I TB2B _ I G ROOM
IIL I li
TB3C I r-- .... ,
I H ROOM
,,..... _o__j L£_:
Branch box_2
(3-branch type)
Fig. 7-3
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.
® Power supply single phase AC208/230 V, 60 Hz
Max. Permissive System Impedance 0.22 (_)
Note:
(_ Power supply input: Outdoor unit only.
Connect the lines (C), (D) in accordance with the terminal block names to
ensure correct polarity.
Wire diameter Breaker "1
(A) Main power (B) Ground (C) Signal line (D) Signal line interrupting Performance
line current characteristic
10.6 mm _ 10.6 mm _ 1.65 mm _ 1.65 mm _ 50 A, 30 mA for
5O A
AWG7 AWG7 AWG15 *2 AWG15 *2 0.1 sec. or less
Maximum circuit ampacity Maximum rating of over-current protector device
32 A 52 A
When using twisted wire for the wiring, the use of round terminal is required.
• 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").
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.
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 fixing positions of the grounds for the sig-
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.
Z_, 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 Sl, 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.
Power supply
Isolator (Switch)
$1
Outdoor unit $2
$3
3 poles isolator (Switch)
Sl Sl _ ................................
S2 Branch S2
box
S3 S3
"A-control"
$2
Indoor unit
$3
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