H Feeding Generated Solar Power Into The Grid; H Lightning Protection - Viessmann Vitovolt 200 Technical Manual

1.3 Photovoltaic system
Feeding generated solar power into the grid
A Photovoltaic panel
B Inverter
C Feed meter
Lightning protection
Lightning protection systems must be
differentiated between systems for
protecting against direct or indirect
lightning strikes.
External lightning protection in case of
direct lightning strikes
Only in exceptional cases will a lightning
protection system be required after
installing a photovoltaic system, e.g. in
particularly exposed locations.
If a lightning protection system is
installed for the building, the fixing
construction of the PV panel must be
connected to this with a short connection.
Otherwise the fixing construction must be
connected to the earthing cable with a
suitable, electrically sound wire, e.g.
heating pipes or continuous metal DHW
pipes, that must also be connected to an
earthing conductor. Observe the
requirements of DIN VDE 0190.
8
B
C
For separate fixing designs, ensure
satisfactory earthing and that an
adequate distance to roof−mounted
power supply masts is maintained. As
roof standards must not be earthed,
contact of both parts must be prevented.
Buildings which are not equipped with a
lightning protection system should not be
equipped with such a system for the
photovoltaic system either, as dangerous
excess voltages could be induced through
photovoltaic systems protected by
lightning conductor systems and
earthing. If the photovoltaic system
noticeably protrudes above the roof line,
e.g. on flat roofs, the installation of a
lightning protection system should be
assessed by an expert.
Due to the fixed payment for power
generated by photovoltaic systems
prescribed by the Renewable Energy Act
(EEG) [Germany], see page 3, almost all
systems in Germany are installed to feed
their power into the grid. This power is
almost exclusively fed into the grid. The
A
power required for domestic purposes is
completely drawn from the grid through a
sealed junction box equipped with mains
fuses.
A meter box housing the supply
electricity meter is located downstream of
the junction box. The power generated by
the photovoltaic process is fed into the
grid immediately upstream of the supply
meter. A feed meter is required to
measure the power fed into the grid, i.e.
additional meter space should be
allocated.
Meters generally belong to the power
supply company, which normally charges
rent for such meters.
Only authorised electricians may connect
photovoltaic systems to the grid.
Generally this installer would also clarify
the terms of connection with the local
energy supply company.
Internal lightning protection against
voltage surges
Anti−surge conductors in the inverter
protect the panels and the electronics
against dangerous voltage surges.
Voltage surge conductors are more
efficient the closer they are fitted to the
photovoltaic panel, where necessary at
the expense of accessibility.
VITOVOLT