SMA SC 100LV-560HE - Manual (Page 11)

SMA Solar Technology AG Safety
Installation Guide SC125_560HE-IEN083220 11
2.2.3 Special Hazards of Photovoltaic Systems
Photovoltaic systems have special characteristics representing special hazards that are described
here:
• An active power source is connected. Depending on the operating mode there may be voltage
present, either from the photovoltaic generator and/or the Sunny Central. This is especially
important to note when disconnecting parts of the system
• Very high DC voltages are present (no zero-crossing) that, in the case of a fault or inappropriate
use of fuses or plugs, may lead to arcing.
• The short-circuit current of the photovoltaic generator is only slightly more than the maximum
operating current and is also dependent on the level of solar irradiation. If a short-circuit occurs
in the system, the available fuses are not guaranteed to switch off.
• The grid structure of the PV generator is usually an IT grid, i.e. a non-grounded grid that could
become unintentionally grounded if a ground fault occurs.
• A highly branched generator may be difficult to disconnect if a fault develops (e.g. short-circuit).
In addition, we recommend the use of external DC circuit breakers for disconnecting the inverter
and/or the DC main cables / Sunny String monitors (DC circuit breakers are optionally
available). At every DC input, an easily accessible DC circuit breaker should be installed
(for further information see pre-standard VDE 0100, part 712 and VDI guidelines 6012).
2.2.4 Electrical Connection
The electrical connection must be carried out according to the installation guide, the relevant circuit
diagram and the technical data of the device.
Ensure the grid connection cable for grid feeding is fused at the nominal current indicated on the type
plate. If the specified nominal current differs from the nominal current of the fuse plug, the fuse plug
having the next highest nominal current may be used.
Lightning protection
The devices are equipped with an internal overvoltage protection on the AC and DC sides. The
desired protection level can only be achieved, if a lightning protection area concept exists for the
installation building according to DIN VDE 0185-4, which means that at the building's entrance
(transfer lightning protection area LPZ 1), lightning conductors or combined surge and lightning
conductors are available among others which are not included in the delivery.
The combined surge and lightning protection for the signal inputs can be optionally ordered.
Grid connection cable
The grid connection cable for the internal power supply must be fused with the line circuit
breakers specified in the technical data.