The aim of the circuit breaker diagnostics is maintenance philosophy change from time-based maintenance to maintenance based on the condition of the concrete circuit breaker.
Diagnostics tests and measurements are conducted on a network-isolated circuit breaker which is short-circuited and grounded on one side, as shown on the image below.
Field tests include diagnostic tests of HV circuit breakers, switchgear and controlgear, metal-enclosed SF6 switchgear and controlgear and metal-enclosed busbars.
High voltage circuit breaker diagnostics includes the following tests:
- operating times
- current and voltage of closing and trip coils
- contact speed
- the voltage drop of the main circuit
- SF6 quality
- blockades check