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InstallatIon and oPERatIon ManUal FoR sl2 solaR ModUlEs oF tHE GEnERatIon G2.1 and G2.2
5.1 FunctIonal groundIng oF tHe negatIVe pole
Solibro solar modules are to be principally protected against nega-
tive voltages with regard to the ground potential on the generator
pole!
in most cases, this is realized by connecting the negative pole of
the array (systems with galvanic separation between the direct
and alternating voltage sides) with the ground potential.
Many inverter manufacturers offer grounding kits for their inverters:
¼
Functional grounding of the negative pole
Pv system
Functional grounding kit negative
DC/ACinverter
isolating transformer
inverter unit
=
~
PV+
PV-
Systems without galvanic separation between Dc and Ac sides
generally do not meet the requirements for functional grounding.
ground fault protection
For appropriate protection against Dc residual currents, Solibro
recommends selecting inverters with the following functions:
insulation resistance measurement prior to grid connection
countermeasures against excessively high residual current
countermeasures in the event of sudden changes to the
residual current
Depending upon the inverter topology, these functions are the
prerequisiteforinvertersthatfulfiltheIEC62109-2standard.
As a
minimum requirement,
it must be ensured that the following
residual currents are not exceeded*:
Module type
SL2 (unframed)
SL2-F (framed)
ground-mounted systems/
utility
max. 2 A
max. 2 A
rooftop systems
max. 300 mA
max. 1 A
*The valid regulations for personal protection remain unaffected.
5 groundIng
in most cases, the fault current limitation is realized via the
grounding kit of the respective inverter manufacturer. A fault
current can be limited by a fuse, a resistor or a RcMu system
(“Residual current Monitoring Device”). Please contact the in-
verter manufacturer as whether the above mentioned minimum
requirements are met (see table).
maximum permissible functional grounding resistor
in the event that a resistor is used between the negative pole and
the ground, the size of the resistor may not exceed the following
values:
Modules in series
9
8
7
6
5
r
max
[kΩ]
450/n
570/n
745/n
1015/n
1416/n
Modules in series
4
3
2
1
r
max
[kΩ]
2280/n
4055/n
9125/n
36505/n
n ...number of parallel connected strings per inverter
For safe functional grounding:
¼
use an inverter that is suitable for functional grounding.
¼
Ground negative generator pole with a grounding kit recom-
mended by the inverter manufacturer; with which the ground-
ing corresponds to the requirements named above.
¼
observe the regulations of the inverter manufacturer.
¼
in the case of direct grounding, ensure that the grounding
presents no danger to persons.
¼
Observepersonalprotectionandfireregulations.
Pleasecontactourcustomerservicetofindaninvertersuitable
for your application.
