SMA SC 100 Indoor Installation - Manual (Page 10)

Safety Instructions SMA Solar Technology AG
10 SC-100-IEN093231 Installation Guide
3.7 Special Hazards of Photovoltaic Systems
Photovoltaic systems have special characteristics representing special hazards:
• An active power source is connected. This means that, 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 particular parts of the system
• Very high DC voltages are present (no zero-crossing) which, in 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. This means that, if a
short circuit occurs in the system, the existing circuit breakers are not guaranteed to switch off.
• A highly branched generator array may be difficult to disconnect if a fault develops (e.g. short
circuit). We recommend the extra use of external DC circuit breakers for disconnecting the
inverter and/or the DC main cables / Sunny String monitors (DC circuit breakers optionally
available). One circuit breaker should be allocated to each input, and these should be located
near to the Sunny Central, as described in the standard VDE 0100 part 7-712 and the
VDI 6012 regulations.
3.8 Electrical Connection
The electrical connection must be performed according to the installation guide, the device connection
plan and the technical data of the device.
AC Grid Connection
The customer must determine the required grid connection type for the AC grid connection
(TN-C, TN-S, TT grid) and coordinate it with SMA.
Ensure the grid connection cable for grid feeding is fused at the nominal current indicated on the name
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. A power switch is used for the optional load-
disconnecting switch.
An external input control voltage (optional) must be fused with a circuit breaker conforming to the
specifications in Appendix B (SC100 Indoor / Outdoor technical data).
DANGER!
An active power source is connected!
NOTICE!
SMA must be informed of the required AC grid connection type!