Overvoltage protection devices

Seamless and safe

Every year, several hundred thousand cases of damage from lightning strikes and overvoltages are reported in Germany alone, with resulting costs in the multi-million euro range. Play it safe – with overvoltage protection devices from our SENTRON portfolio! These devices are part of a comprehensive protection concept for electrical installations, and reliably prevent damage from  overvoltage.

Find the overvoltage protection devices to fit your needs.

Siemens Industry Mall

5SD7 lightning arresters, type 1

5SD7 lightning arresters, type 1

  • Protects low-voltage systems against overvoltage and high currents triggered by direct or indirect lightning strikes
  • Enclosed lightning arresters suitable for installation upstream of the meter
  • All design variants fitted with remote signaling contact
  • Suitable for installation in main distribution boards, upstream or downstream of the meter

5SD7 combination surge arresters, type 1 and type 2

5SD7 combination surge arresters, type 1 and type 2

  • Protects low-voltage systems against overvoltage and high currents triggered by direct lightning strikes 
  • Thermal isolating arrester disconnector offers a high level of protection against overload
  • All design variants fitted with remote signaling contact
  • Suitable for installation in main distribution boards downstream of the meter

5SD7 combination arrester, type 1 and 2

5SD7 combination arrester, type 1 and 2

  • Compact designs that can be used as both lightning arrester (type 1) as well as surge arrester (type 2)
  • Protects low-voltage systems against overvoltage triggered by lightning strikes or grid switching operations
  • Thermal isolating arrester disconnector offers a high level of protection against overload

5SD7 surge arresters, type 2

5SD7 surge arresters, type 2

  • Protects low-voltage systems against transient overvoltages
  • For installation downstream of lightning arresters 5SD7, type 1 in main distribution boards or subdistribution boards 
  • Remote signaling contact notifies whether a protection module has been disconnected from the grid by the thermal isolating arrester or whether a protection module is not plugged in
  • Note: It is essential to have standardized protection against lightning and voltage spikes to ensure error-free operation of photovoltaic systems!

5SD7 surge arresters, type 3 for measuring and control technology

5SD7 surge arresters, type 3 for measuring and control technology

  • Overvoltage protection modules designed to comprise two parts: a base element and a plug-in component 
  • Used to protect instrument signal circuits
  • Cable shields of the base elements may be connected directly or indirectly to the ground
  • Protects up to four signal cores or two dual-wire lines against overvoltages
Protection for buildings and plants

The danger of lightning: Damage from overvoltage

Overvoltages are brief voltage peaks of less than a thousandth of a second that exceed by many times the allowable design operating voltage of electric devices. Such overvoltage events are usually caused by lightning strikes, electrostatic discharges or power grid switching operations, and are extremely hazardous. Such surges can cause electrical systems to fail, destroy electrical and electronic equipment, or even set entire buildings on fire. An appropriate protection concept should therefore be implemented in every building.

Protection in three levels

It's best when all electrically live cable routes in the building exposed to hazards are safeguarded by suitable protection devices according to a systematic “graded protection” concept: Beginning with the end device and all the way upstream to the entry of the power lines into the building, all power lines as well as the communication lines should be provided with overvoltage protection devices of various performance classes. The protection devices shall be selected in accordance with the electrical loads at the site of installation. This concept enables implementation of overvoltage and lightning protection measures tailored to local conditions and individual requirements.

The right device for any requirement

Among other characteristics that differentiate overvoltage protection devices is their rated surge capacity and the achievable level of protection.  

  • Type 1 lightning arrester: Protects against overvoltage and high currents triggered by direct or indirect lightning strikes
  • Type 2 surge arrester: Protects against overvoltage triggered by electrical switching operations
  • Type 3 surge arrester: Protects electrical loads (consumers) against overvoltage
Insulation coordination in accordance with IEC 60364-4-443

Download table

50 percent of lightning current remains within the building

According to IEC 61312-1, it is to be assumed that approximately 50 percent of any lightning current is conducted via the external lightning protection system (lightning arrester) into the ground. Up to 50 percent of the remaining lightning current flows via electrically conductive systems into the building. Overvoltage protection measures are therefore absolutely essential, even if a building or installation is fitted with a lightning arrester.

Downloads and Support

Take advantage of our services

Here you will find important information, documents, and addresses relating to low-voltage power distribution and electrical installation technology.

Order overvoltage protection devices

Overvoltage protection devices protect against thunderstorm damage

Learn more, choose, and order: At the Industry Mall you will find detailed technical information about all of our overvoltage protection devices. You are just a few clicks away from your customized solution for protecting against damage from lighting and overvoltage.

Find the overvoltage protection devices to fit your needs.

Siemens Industry Mall

Related links