Mitsubishi Electric PAC-MKA50BC Manuel D'installation page 11

8. Electrical work
A
208/230V
Fig. 8-11
Total operating current of the indoor unit
F0 = 15A or less *2
F0 = 20A or less *2
F0 = 30A 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 Please 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)
Indoor unit
Type 1 SEZ-KD•NA, PLA-A•BA
Type 2 PEAD-A•AA, MVZ-A•AA
Type 3 MSZ-FE•NA
Type 4 MSZ-FH•NA, MSZ-GE•NA
Type 5 SLZ-KA•NA
Type 6 MFZ-KA•NA
Type 7 Branch box (PAC-MKA•BC)
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•NA × 5, C=8 (refer to right sample chart)
F2 = 5.1 × 2/8 + 19.8 × 5/8
= 14.9
→ 16A breaker (Tripping current = 8 × 16A at 0.01s)
*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 /AWG)
2.1/14
3.3/12
5.3/10
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.
＊Power supply from Outdoor unit
L1
Isolator (Switch)
Power supply
L2
＊Supply power separately to branch box and outdoor unit
L1
Power supply
L2
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.
B D
L1 L2
M1 M2
C
S
TB2B TB5
Minimum wire thickness (mm²/AWG)
Main cable Branch
2.1/14 2.1/14
3.3/12 3.3/12
5.3/10 5.3/10
V1 V2
19.8
26.9
9.9
2.4
6.8
3.5
16.2
5.1 3.0
V3
48 Indoor unit
56 Branch Box
66
L1 L1
Outdoor unit
L2 L2
L1
L1
Isolator (Switch)
Branch box
L2
L2
sandium.com
Power supply wiring (Supply power separately to branch box
and outdoor unit)
• Install an earth line longer than other cables.
• Power supply cords of appliance shall not be lighter than design 245IEC57 or
227IEC57, 245 IEC 53 or 227 IEC 53.
• A switch with at least 3 mm, 1/8 inch contact separation in each pole shall be
provided by the air conditioner installation.
[Fig. 8-11]
Ground-fault interrupter
A
Local switch/Wiring breaker
B
Branch Box
C
Pull box
D
Ground Capacity Fuse
2.1/14 15
3.3/12 20
5.3/10 30
V2
2.4
3.0
2 pole isolator
(Switch)
L1
L1
Branch box
L2
L2
3 pole isolator
(Switch)
S1
S1
S2 "A-control
S2
Indoorunit"
S3
S3
Breaker for wiring
Ground-fault interrupter *1
(NFB)
15 15 15A current sensitivity *3
20 20 20A current sensitivity *3
30 30 30A 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
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