scope:

This standard is applicable to surge suppression varistors intended to protect electronic and other sensitive equipment from surges, operating from a.d.c supply, or an a.c. supply having a frequency not greater than 400 Hz. Varistors which are the subject of this sectional specification are not intended to give primary protection against lightning surges. The object of this standard is to prescribe preferred ratings and characteristics and to select from IEC Publication 1051-1, the appropriate quality assessment procedures, tests and measuring methods and to give general performance requirements for this type of varistor. Test severities and requirements prescribed in detail specifications referring to this sectional specification shall be of equal or higher performance level, because lower performance levels are not permitted.