Appendices
Appendices
76
GenStar MPPT
77
Minimum Battery Wire Sizing
-
75
ºC rated copper
MODEL
Wire Size in a raceway, cable,
or earth
1
Wire Size in free air
2
Metric
Wire Size
3
(mm
2
)
@30ºC
30º-45ºC
@30ºC
30º-45ºC
GS-MPPT-60
#4 AWG
3 AWG > 40°C
#6 AWG
#6 AWG
16 - 25
GS-MPPT-80
#3 AWG
2 AWG > 30°C
1 AWG > 40°C
#4 AWG
#4 AWG
25 - 35
GS-MPPT-100
#1 AWG
1/0 > 30°C
2/0 > 40°C
#4 AWG
3 AWG > 30°C
2 AWG > 40°C
35 - 50
NOTES:
1 Per NEC 2021 [see NEC Table 310.15(b)(16)], ampacity for not more than three current-carrying
conductors in a raceway, cable, or earth (buried)
2 Per NEC 2021 [see NEC Table 310.15(b)(17)], ampacity for conductors in free air
3 Estimated. See local code requirements for metric cable sizing
Table A-2. Minimum DC battery wire sizes for
75
ºC copper
Minimum Output/Load Wire Sizing (based on breaker or fuse sizes)
Breaker or
fuse Rating
@30ºC
Metric
Wire Size
(mm
2
)
15 Amps
#14 AWG
2.5
20 Amps
#12 AWG
4
25 Amps
#10 AWG
6
30 Amps
#10 AWG
6
40 Amps
#8 AWG
10
Table A-3. DC load output wire sizes
2% Voltage Drop Chart for 75°C or 90
º
C Stranded Copper Wire
Maximum 1-way distance (feet), 12 Volt system - multiply values by (2) for 24 Volt,
and by (4) for 48V, system
Wire
Size
(AWG)
100A
90A
80A
70A
60A
55A
50A
45A
40A
35A
30A
25A
20A
15A
4/0
1
23.5
26.1
29.4
33.6
39.2
42.8
47.0
52.3
58.8
67.2
78.4
94.1
117.6 156.8
3/0
1
18.7
20.7
23.3
26.7
31.1
33.9
37.3
41.5
46.7
53.3
62.2
74.7
93.3
124.5
2/0
1
14.8
16.4
18.5
21.1
24.6
26.9
29.6
32.9
37.0
42.3
49.3
59.2
73.9
98.6
1/0
11.7
13.0
14.7
16.7
19.5
21.3
23.4
26.0
29.3
33.5
39.1
46.9
58.6
78.1
#1
9.3
10.3
11.6
13.3
15.5
16.9
18.6
20.6
23.2
26.5
31.0
37.1
46.4
61.9
#2
7.4
8.2
9.2
10.5
12.3
13.4
14.7
16.4
18.4
21.1
24.6
29.5
36.9
49.1
#3
5.8
6.5
7.3
8.3
9.7
10.6
11.7
13.0
14.6
16.7
19.5
23.3
29.2
38.9
#4
4.6
5.2
5.8
6.6
7.7
8.4
9.3
10.3
11.6
13.3
15.5
18.6
23.2
31.0
#6
3.6
4.2
4.9
5.3
5.8
6.5
7.3
8.3
9.7
11.6
14.6
19.4
#8
3.1
3.3
3.7
4.1
4.6
5.3
6.1
7.4
9.2
12.3
#10
2.9
3.3
3.8
4.6
5.8
7.7
#12
2.9
3.6
4.8
#14
2.3
3.0
1
Wires sizes larger than 1/0 AWG must be terminated at a splicer block located external to the GenStar MPPT.
Use 1/0 AWG or smaller wire to connect to the GenStar MPPT to the splicer block.
Table A-4. Maximum 1-way wire distance for 12 Volt systems, stranded copper, 2% voltage drop
