VOLTWERK VS 3 Instrucciones De Servicio página 74

3 Technical description
Surge voltage protection
The inputs of the solar power system and the outputs to the
public grid are fitted with Category D (type 3) surge voltage
protection. The surge voltage protection does not provide
protection against higher DC voltages (for voltage values,
see chapter 3.7, page 19).
Monitoring of the public grid
For safety reasons, all photovoltaic systems must be
disconnected from the public power grid in the following
situations:
| In the case of disconnection or failure of the electricity grid
| In the case of electricity grid faults such as voltage
fluctuations, fault currents or frequency changes
String inverters use the "phase-shifting method" for grid
monitoring. If there is a fault in the public power grid, each
Voltwerk VS series string inverter detects this fault due to the
change in frequency of the current. The string inverter
switches off. The inverter waits 2 minutes before switching
back on after a grid fault.
Optional: Parameterisation tool StringInverter Setup
A computer with the parameterisation tool StringInverter
Setup has the function to check network parameters of the
string inverters connected, and change them within the
bounds of legal requirements, if necessary. Moreover, you
can use the software to read off all saved values by the
inverter, including fault indicators.
Voltwerk VS 3, 4, 5 11
Operating manual