•
•
brown (or another colour such as black or grey) is used for the phase.
In the United States and Canada,
silver is used for neutral,
green-yellow, green or a bare conductor is used for the protective earth, and
and black (or another colour) is used for the phase.
In India and Pakistan, for example
black is used for neutral,
green is used for the protective earth and
blue, red, or yellow is used for the phase.
Therefore it is very important to check the standards of the country in which the PV
system is going to be installed.
The cables have to be chosen such that resistive losses are minimal. For estimating
these losses, we look at a very simple system that is illustrated in Figure 19.27 The system
consists of a power source and a load with resistance R L , and the cables have a resistance
R cable , which is also shown. The power loss at the cables is given as
where ΔV cable is the voltage drop across the cable, which is given as
Using
we find
Hence, as the current doubles, four times as much heat will be dissipated at the cables. It is
now obvious why modern modules have all cells connected in series.
Figure 19.27: A circuit with a load R L and cable resistance R cable . The connections drawn in between the components
are lossless.
Let us now calculate the resistance of a cable with length l and cross-section A. It is
clear that if l is doubled, R cable also doubles. In contrast, if A doubles, R cable halves. The
resistance is thus given by
•
brown (or another colour such as black or grey) is used for the phase.
In the United States and Canada,
silver is used for neutral,
green-yellow, green or a bare conductor is used for the protective earth, and
and black (or another colour) is used for the phase.
In India and Pakistan, for example
black is used for neutral,
green is used for the protective earth and
blue, red, or yellow is used for the phase.
Therefore it is very important to check the standards of the country in which the PV
system is going to be installed.
The cables have to be chosen such that resistive losses are minimal. For estimating
these losses, we look at a very simple system that is illustrated in Figure 19.27 The system
consists of a power source and a load with resistance R L , and the cables have a resistance
R cable , which is also shown. The power loss at the cables is given as
where ΔV cable is the voltage drop across the cable, which is given as
Using
we find
Hence, as the current doubles, four times as much heat will be dissipated at the cables. It is
now obvious why modern modules have all cells connected in series.
Figure 19.27: A circuit with a load R L and cable resistance R cable . The connections drawn in between the components
are lossless.
Let us now calculate the resistance of a cable with length l and cross-section A. It is
clear that if l is doubled, R cable also doubles. In contrast, if A doubles, R cable halves. The
resistance is thus given by