Permanent overvoltages are voltage surges above 10% of the nominal value of the distribution network which are maintained for several cycles or permanently. They are normally caused by a defective connection of the neutral or by a failure in the transformation centre.

The counter, with reference AT-3502, indicates the overvoltages that have occurred in an installation.

Protects against transient overvoltages, permanent overvoltages and undervoltages, includes self-reclosing feature.

The consumption of energy provided by photovoltaic panels has increased significantly during the last years.