Mitsubishi Electric MXZ-8B48NA Installation Manual page 13

7. Electrical work
<Example> (In case of 2-branch boxes) 7.3. External wiring procedure (Fig. 7-3)
Branch box! The power supply work is needed only to the outdoor unit. The power supply to the
(5-branch type) branch box or indoor unit is conducted through wiring.
oo TB3A | Indoor unit Therefore, the power supply work can be carried out at just one spot of the outdoor
Outdoor unit | Sp! (0) TE ep AROOM unit. It will contribute to simplifying the work and saving costs.
— | Sr —_iLtep © Power supply single phase AC208/230 V, 60 Hz
(A) (A) CD | SDH 4-83 | |! Max. Permissive System Impedance 0.22 (Q)
© ED | D1 —+-© |
Circuit LGB | TB2B BSB. | a Note:
2 ) {CO | = -(Di =e; BROOM .
breaker ee. Si SD SDH q re | @ Power supply input: Outdoor unit only.
SS i 2 & LI 7 & | Connect the lines (C), (D) in accordance with the terminal block names to
crt es eet tana Ge | ensure correct polarity.
boon = = = 1
OL | TB3C = 5 Wire diameter Breaker *1
1 @ Si ror Si | © ROOM (A) Main power!(B} Ground —|(C) Signal line](D) Signal line|interrupting | Performance
| = r t | line current characteristic
| ASTpssy Ces | 10.6 mm? | 10.6mm? | 1.65 mm? | 1.65 mm? 50 A | 50.4: 30. mA for
| & p w Ts @_ 4 AWG7 AWG7 AWG 15 *2 | AWG15 *2 0.1 sec. or less
| Pep Hoe Fep] | 2 ROOM
\! u l '
| & ' 1 | | = | Maximum circuit ampacity Maximum rating of over-current protector device
| Qt te | 32 A 52A
| @ t~@ -4
m44-F A! TBSE -(D)1 ase=7! EROOM When using twisted wire for the wiring, the use of round terminal is required.
(©) iH Si 1 t 1 fr Si | *1_A breaker with at least 3 mm [1/8"] contact separation in each pole shall be provided. Use
~ TTT! i in 2 | earth leakage breaker (NV).
| SN [r= @ | *2. Max. 45 m (147 ft.) ("Outdoor unit - Branch box #1" plus "Branch box #1 - Branch box #2").
L-—-__ awl LL a
= i i t
r TB3A | (1) nee
| Sj | i S| | F ROOM Notes:
| Se m t SD | | 1. Wiring sizes must comply with the applicable local and national code.
[Sy A==S | Se 2. Use wires rated 600 V or more for the power supply cables and the indoor
S+—+—-© | unit/branch box/outdoor unit connecting cables.
| ea | cD) [rep | GROOM 3. Install ground wires longer than power cables.
| 1828 ® | | Ll | ! 4, Use separate conduit holes for power lines (3 lines) and signal lines (4 lines) .
$1 SD-- Le SB | 5. The inner diameter of a wiring conduit for the power line is required to be
| & S t t © | more than 10.1 mm (7/16").
| TB3C | TT 6. Since the distances between the fixing positions of the grounds for the sig-
| © Si ! HO) L $i | H ROOM nal lines and the terminal blocks for the signal lines are long, the ground
| SDH — l 1S wires for the signal lines are 180 - 200 mm (7-1/16" - 7-7/8") longer than the
Sd 7S | signal lines .
ro _! 7. Use copper supply wires.
Branch box*2
(3-branch type)
. IMPORTANT
Fig. 7-3 Make sure that the current leakage breaker is one compatible with higher
harmonics.
Always use a current leakage breaker that is compatible with higher
harmonics as this unit is equipped with an inverter.
The use of an inadequate breaker can cause the incorrect operation of
aa
aA 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 $1, $2, 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
3 poles isolator (Switch)
Isolator (Switch) ZZ _—
$1 $1 $1 $1
' Branch "A-control"
i t $2 $2 $2 :
Outdoor unit co box oo Indoor unit
$3 Lo 83 83 Lo s3
AX 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.
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