scope:

Scope and Object 

This International Standard applies only to ground mounted high-voltage (HV) circuit-breakers, the supporting structures of which are rigidly connected with the ground, and does not cover the seismic qualification of circuit-breakers in metal enclosed switchgear.

The seismic qualification of the HV circuit-breakers shall take into account any auxiliary and control equipment which is mounted on the circuit-breaker structure. If the auxiliary and control equipment is mounted on a separate structure, it may be qualified independently.

This standard is a guide providing procedures to seismically qualify HV alternating-current ground mounted circuit-breakers. It is mainly based on IEC 68-3-3, which in turn refers to IEC 68-1, IEC 68-2-6, IEC 68-2-47 and IEC 68-2-57.

The seismic qualification of a circuit-breaker is only performed upon request.

This standard specifies seismic severity levels and gives a choice of methods that can be applied to demonstrate the performance of HV circuit-breakers for which seismic qualification is required.