BS EN 60255-21-3:1995

This International Standard is one of a series of parts specifying the vibration, shock, bump and seismic requirements applicable to electromechanical and static measuring relays and protection equipment, with or without output contacts.

This standard includes two alternative types of seismic tests (see Annex A):

• the single axis sine sweep seismic test (method A); and

• the biaxial multi-frequency random seismic test (method B).

During preparation of this standard, it was determined that the number of countries in which the first test method was preferred was about equal to the number of countries in which the second method was preferred. For this reason both methods have been retained, and neither have been identified as reference (or “referee”) method.

The requirements of this standard are applicable only to measuring relays and protection equipment in a new condition.

The tests specified in this standard are type tests.

The object of this standard is to state:

• definitions of terms used;

• test conditions;

• standard test severity classes;

• test procedures;

• criteria for acceptance.