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aleo solar Deutschland GmbH
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installation instructions Edition 01/2012 en-GB-Intl (120508b)
C.
Optimisation of Wiring for Lightning
Protection
NOTICE
Plan the laying of the cables so that the cables of a
circuit span as small an area as possible. This mini-
mises the likelihood of damages in the event of a
nearby lightning strike.
The smaller the area that the wiring covers, the smaller the
voltage that the magnetic field of a lightning current (e.g.
through a nearby lightning conductor) induces in the con-
ductor loop (of the module string circuit).
Lay all the cables of the module string as described as
follows:
form as small loops as possible
lay loops next to one another with alternating
current directions
lay the return circuit of the string as close to the
outgoing circuit as possible.
More careful wiring can pay off in a lower potential for
damage. The following chapters describe these wiring
recommendations in greater detail.
C.1.
Keep loops small
When laying cables in loops, e.g. the cables between two
connected modules, keep the diameter of the loops as small
as possible. In doing so, please observe the smallest per-
missible bending radius of the cables.
It may be advantageous to lay the loop in the shape of an
eight. Doing so keeps the area subject to a coupling effect
from lightning current particularly small.
Recommended laying of loops
Fig. 39 Recommended minimizing of cable loops (diagram)
a
: loop in a figure of eight,
b
: small loop with a minimal
bending radius,
c
: extended loop.
The coupling effect in the area of loop
a
is approxi-
mately cancelled out due to the opposed direction
of current flow (minor coupling effect).
The area of loop
b
is small (somewhat greater
coupling effect).
The area of loop
c
is smaller than a circular,
extended loop (greater coupling effect).
Loop configurations to be avoided
Fig. 40 Large cable loops to be avoided (diagram)
a
: unnecessarily large loop,
b
: loop with an additional small
loop.
The area of loop
a
is greater than that of a
stretched loop (great coupling effect).
The area of loop
b
is, due to the same current
direction, increased by the area of the additional
coil (even greater coupling effect).
GID AS048a
d=d
min
a
d=d
min
b
min
d=d
c
GID AS049a
d>d
min
a
b
d>d
min
