How to choose surge protective devices, surge protection devices
Choosing the right surge protection devices and protective circuit breakers (or fuse) involves a considering a wide range of parameters related to types of surge protection devices, circuit breaker (or fuse) arrangements and risk assessment.
Current standards define three categories of surge protective devices for low-voltage electrical installations:
Type 1 Simplified selection principle (excluding full risk assessment)
Install in the main switchboard in buildings with lightning protection systems Can discharge very powerful lightning currents.
Should be used as part of lightning protection systems, i.e. when lightning rods or meshed cages are installed
Install in the main power distribution switchboard.Discharge currents from indirect lightning strikes, inductive and conductive over-voltages, and switching transients.
Should always be used.
Dedicated to the protection of specific devices.Very low discharge capacity.
Supplementary surge protective devices:
Used in Types 1+2+3 combinations in industrial facilities where a lightning protection systems is in place
Used in Types 2+3 combinations when there is no lightning protection systems.