aleo
aleo solar Deutschland GmbH
| Osterstraße 15| 26122 Oldenburg | Germany | [email protected]
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installation instructions Edition 01/2012 en-GB-Intl (120508b)
Connection
The following circuit diagram shows how to install the string
diodes:
Fig. 13 Connection of string diodes, diagram (schematic)
Arrangement
Only use string diodes:
in which the continuous forward current is suitable
for at least the maximum expected short-circuit
current of the module string (I
SC, max
)
-AND-
in which the reverse voltage is also suitable for at
least double the maximum open circuit voltage of
the module string (U
OC, max
), so that the diode will
not be damaged if a module string is accidentally
reverse-poled.
5.12.7.
Direct current string fuses
WARNING
For string fuses, only use direct current fuses that are
approved for photovoltaic systems and which safely
extinguish the direct current electric arc when
triggered.
RECOMMENDATION
If an unearthed module string has been installed, both
connections of the module string
⊕
and
⊖
have a
floating voltage to earth. In this case, install a direct
current string fuse in both connections of the module
string. Some inverters are equipped with fuse holders
that can be fitted with fuses where necessary.
aleo solar recommends the installation of direct current string
fuses. These protect the modules in the event of faults (e.g.
faulty inverter, lightning strike). Direct current string fuses
also offer basic protection against stray currents and can help
prevent fire.
Local regulations may even stipulate the use of direct current
string fuses.
Specify the fuses in such a way that they are triggered if the
current exceeds the maximum reverse current (I
REV
) stated in
the corresponding data sheet for the modules. Only a trained
professional should carry out the dimensioning of the fuses.
Corresponding information materials is available from the fuse
manufacturers.
If string diodes are required (see Ch. 5.12.6, 'String diodes')
always install direct current string fuses in addition to the
string diodes.
5.12.8.
Inverter connection
WARNING
Make sure that all necessary safety components have
been planned for when connecting the inverter. These
include – depending on specific local regulations – for
example, DC isolators, direct current string fuses,
and/or short-circuiters.
NOTICE
If your inverter allows a one-sided earthing of the
photovoltaic generator and you would like to earth your
photovoltaic generator, aleo solar recommends
earthing the negative
⊖
connection
5
of the module
strings. See also Ch. 10.6, 'Potential Induced
Degradation (PID)'.
aleo solar recommends installation of the following
components:
a fire prevention switch – in a position located
before the cables of the photovoltaic generator
enter the building
a direct current string fuse in every connection
⊕
/
⊖
of a string (2 fuses per string) at every
inverter input
a double DC isolator between every string of the
photovoltaic generator and the corresponding
string connection to the inverter.
DC isolators, direct current string fuses, or short-circuiters are
already integrated in some inverters. National regulations
may, however, stipulate the use of external components.
5
The recommendation to earth the negative
⊖
connection
applies to all currently manufactured aleo modules that
contain cells with p substrate. In the future, aleo solar may
also offer modules that contain other cells (with n substrate).
A special, alternative earthing recommendation may then
apply for these modules.
GID AS013b
⊕
⊖
∼
=
G
ID A
S
033
c
G
ID A
S
033
c
