Mitsubishi Electric BRANCH BOX PAC-MK52BCB Manuel D'installation page 12

8. Electrical work
Total operating current of the indoor unit
F0 = 16A or less *2
F0 = 25A or less *2
F0 = 32A or less *2
Apply to IEC61000-3-3 about max. permissive system impedance.
*1 The Ground-fault interrupter should support inverter circuit.
The Ground-fault interrupter should combine using of local switch or wiring breaker.
*2 Take the larger of F1 or F2 as the value for F0.
F1 = Total operating maximum current of the indoor units × 1.2
F2 = (V1/C)
Connect to Branch box (PAC-MK•BC)
Indoor unit
Type 1 SEZ-KD•VA, PCA-RP•KAQ, PLA-ZRP•BA(.UK),
SLZ-KF•VA, PLA-RP•EA
Type 2 PEAD-RP•JAQ(L).UK
Type 3 MLZ-KA•VA, SLZ-KA•VAQ(L)3
MSZ-FH•VE, MSZ-SF•VE, MSZ-EF•VE, MSZ-SF•VA,
Type 4
MSZ-GF•VE
Type 5 MFZ-KJ•VE
Type 6 Branch box (PAC-MK•BC)
Type 7 ecodan C generation*5
*This value may increase due to a locally connected actuator.
C : Multiple of tripping current at tripping time 0.01s
Please pick up "C" from the tripping characteristic of the breaker.
Condition: Branch Box × 2 + SEZ-KD•VA × 5, C=8 (refer to right sample chart)
F2 = 5.1 × 2/8 + 19.8 × 5/8
= 13.65
*3 Current sensitivity is calculated using the following formula.
G1 = V2 + V3 × (Wire length[km])
G1 Current sensitivity
30 or less 30 mA 0.1sec or less
100 or less 100 mA 0.1sec or less
2
Wire thickness (mm )
1.5
2.5
4.0
When connecting 3 units of the PLA-ZRP series respectively to the Branch Box
2
1.5mm using 20m of wiring and connecting the Branch Box and PEFY-VMA to
a single breaker using wiring totaling 100m in length;
G1 = 2.4 × 3 + 3 + 1.6 + 48 × 0.02 × 3 + 56 × 0.1
= 20.28
→ 30 mA Current sensitivity
*5 When the ecodan is connected, the master controller (G-50A etc.) cannot be connected.
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 2-pole or 3-pole type, as shown in the fol-
lowing fi gures.
Power supply from Outdoor unit
L
Power supply
N
Supply power separately to branch box and outdoor unit
L
Power supply
N
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.
12
Minimum wire thickness (mm²)
Main cable Branch
1.5 1.5
2.5 2.5
4.0 4.0
V1 V2
19.8
26.9
9.9 2.4
6.8
7.4
5.1 3.0
5.1 5.0*
V3
48
56
66
L L
Isolator (Switch)
Outdoor unit
N N
L L
Isolator (Switch)
Branch box
N
N
Capacity (A) Fuse (A)
Ground
1.5 16
2.5 25
4.0 32
► As for types not listed in the left-side table for indoor units connected
to the branch box, refer to the attached sheet, "Criteria for selecting
breaker when branch box is fed from separate power source".
► As to coefficient (V1, V2) of the LEV kit connected indoor unit and City
Multi indoor unit, refer to the outdoor unit INSTALLATION MANUAL.
2 pole isolator
(Switch)
L
B1
Branch box
B2
N
3 pole isolator
(Switch)
S1
S1
S2 "A-control
S2
Indoorunit"
S3
S3
Breaker for wiring
Ground-fault interrupter *1
(NFB)
16 20 20A current sensitivity *3
25 30 30A current sensitivity *3
32 40 40A current sensitivity *3
Sample chart
6000
600
60
10
1
0.1
0.01
1 2
Rated Tripping current (x)
3 pole isolator
(Switch)
S1
S1
S2
"A-control
S2
Indoor unit"
S3
S3
SAMPLE
3 4 6 8 10 20
C