Breakers and relays sit idle for years and then have to work in milliseconds. High-current testing is how you find out whether they will. We push current through the device and check that it trips at the right level and in the right time, instead of assuming it does.

Where an old electromechanical trip device is past saving, a solid-state retrofit brings in a modern trip unit with better settings and diagnostics, usually without replacing the breaker. Routine cleaning, calibration and repair keep the rest of your protection working.

Typical reasons people call

A breaker failed to open, or opened when it should not have.
Breakers have not been operated or tested in years.
The trip units are obsolete and parts are hard to find.