Do every inverter has a surge protector? Where to install the surge protector in the PV system?

Inverter is indispensable in a PV system. But not every inverter is equipped with a surge protector. Some newer and more advanced inverter models have built-in surge protection as a standard feature, while certain inverters may not have it. For those without built-in surge protection, external surge protection devices need to be installed to safeguard the inverter and the entire PV system.

Regarding the installation locations of the spd surge protector in a PV system, the following are common practices:

· DC Side:

· Usually, two surge protectors can be installed on the DC side of the inverter. One is as close as possible to the PV array (when the distance between the inverter and the PV array is ≥ 10 m, it is generally required; if the distance is less than 10 m and certain conditions of the voltage protection level of the surge protector are met, it may not be necessary in some cases). The other is close to the DC input of the inverter 6.

· In the DC combiner box, a Class 1+2 or Class 2 DC surge protector can be installed to protect the PV modules and the DC side of the inverter from overvoltages caused by lightning induction or direct strikes1.

· AC Side:

· Generally, two surge protectors are installed on the AC side of the inverter. One is installed near the connection between the inverter and the main power distribution cabinet (when the distance between the surge protector of the main power distribution cabinet and the inverter is ≥ 10 m, it is usually required; if the distance is less than 10 m and certain conditions are met, it may not be necessary). The other is as close as possible to the inverter's AC output6.

· In the AC distribution box, a Class 1+2 or Class 2 AC surge protector can be installed to protect the AC side of the inverter and the grid connection from overvoltages caused by lightning induction or direct strikes1.

· In the main power distribution cabinet of the PV system, a Class C surge protector can be installed to protect against AC side lightning currents and overvoltages2.

In addition, for communication lines (such as RS 485 and Ethernet) in PV systems where there is a risk of induced surges, external designated surge protection devices should also be installed.