Surge protection devices
Surge protection devices are electrical equipment whose principal components are voltage dependent resistors (varistors, suppressor diodes) and /or dischargers. Surge protection devices are used to protect other electrical equipment and systems against excess overvoltages and to generate equipotential bonding.
Surge protection devices are subdivided as follows:
a) by their application into:
- Surge protection devices for power engineering systems and devices
- Surge protection devices for information technology system and devices
b) by their surge current conduction capacity into:
- High energy lightning current protectors for interference due to direct strikes or near misses
- Surge protectors for distant strikes, switching overvoltages and discharges of static electricity.
General information
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 operating interruptions.
Applications for power engineering systems and devices
– 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).
Components
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:
