Circuit breaker selectivity – how to prevent the main breaker from tripping during every fault

What is selectivity?

The protective device closest to the fault should, as much as possible, trip before the upstream protection.

Example

If there is a short circuit in a socket, ideally only the breaker for that specific line should trip and not the main switch.

How it is achieved

By correctly selecting current ratings, curves, and protection characteristics.

Why it matters

It reduces power outages and helps locate faults faster.