Victron energy BlueSolar MPPT 150/70 Manual página 7

3.3 PV connection
The PV input current of the charge controller is limited to 50A. In case of a potential
solar array output exceeding 50A, the solar array voltage will increase up to the level at
which the output is reduced to 50A.
The voltage on the PV input should never exceed 150V under any condition.
The charger will be permanently damaged if the input voltage is too high.
The required PV cable cross section depends on array power and voltage. The table
below assumes that maximum PV power has been installed. Cable cross section can
be reduced in case of smaller solar arrays.
The best efficiency is reached at a PV input voltage that is twice the battery voltage.
DC circuit breakers or fuses must be installed in the positive and negative PV cables, to
enable isolation of the charger during installation or maintenance.
The table below gives some examples of cable cross sections calculated with formula
(5).
(in this case I and V are the output current and output voltage of the solar array)
Solar array Solar array
MPP-voltage MPP-current
[V] [A]
18 Max 50A
36 27
54 18
72 13
90 11
108 9
Solar array Solar array
MPP-voltage MPP-current
[V] [A]
36
Max 50A
54
37
72
28
90
22
108
19
12V system (solar array up to 1000W)
Power loss
Length 2x5 meter
in PV cables
2
α (%)
mm
Not recommended
1 16
1 10
0,75 6
0,5 6
0,5 4
24V system (solar array up to 2000W)
Power loss
Length 2x5 meter
in PV cables
2
α (%) mm
35
1
16
1
0,75 10
0,5 10
0,5 6
Length 2x10 meter
2
AWG mm AWG
Not recommended
5 35 2
7 16 5
10 10 7
10 10 7
11 6 10
Length 2x10 meter
2
AWG mm AWG
2 Not recommended
5 25 3
7 25 3
7 25 3
10 16 5
Length 2x20
meter
2
mm AWG
Not
recommended
Not
recommended
25 3
25 3
16 5
16 5
Length 2x20
meter
2
mm AWG
Not
recommended
Not
recommended
35 2
35 2
25 3
7