English 
The number and location of SPDs on the DC side depend on the length of the cables between the solar panels and inverter. The SPD should be installed in the vicinity of the inverter if the length is less than 10 metres. If it is greater than 10 metres, a second SPD is necessary and should be located in the box close to the solar panel, the first one is located in the inverter area.
To be efficient, SPD connection cables to the L+ / L- network and between the SPD’s earth terminal block and ground busbar must be as short as possible – less than 2.5 metres (d1+d2<50 cm).
Safe and reliable photovoltaic energy generation
Depending on the distance between the "generator" part and the "conversion" part, it may be necessary to install two surge arresters or more, to ensure protection of each of the two parts.
Suntree Surge Protection Devices (SPD) are used for electric power supply networks, telephone networks, and communication and automatic control buses.
