Overvoltage protectionOvervoltage protection devices are electrical equipment whose principal components are voltage dependent resistors (varistors, suppressor diodes) and /or dischargers.
Overvoltage protection devices are used to protect other electrical equipment and systems against excess overvoltages and to generate equipotential bonding.
Overvoltage protection devices are subdivided as follows:
a) by their application into:
- Surge voltage protective devices for power systems and devices.
- Surge voltage protective devices for data systems and devices.
b) by their surge current conducting capacity into:
- Lightning arrestors: for adverse effects resulting from direct or near hits
- Surge arresters for remote strikes, switching surges and electrostatic discharge.
Operating failures in measuring, control, data and power lines are often the result of surge voltages on the line. Failure of electronic and semiconductor components due to surges can cause opearting interruptions.
� Overvoltage protection devices for power engineering systems and devices in the voltage range up to 60V (except special solutions, e.g. telephone systems with call voltage).
The boundaries between these levels of protection may not be sharply defined and the devices chosen will vary accordingly. In practice,the following components have proven themselves in these applications: