ANSI/IEEE 28:1974

Revision Standard - Superseded.
This document supersedes IEEE Std 28-1972 (ANSI C62.1-1971) and revises many portions of
the previous edition. Three new significant design tests have been added to determine:
(1) The highest 1.2 x 50 standard impulse which the surge arrester will allow without sparkover
(2) The effect of external contamination on sparkover
(3) Surge arrester disconnector characteristics
Additional substantive changes include:
(1) New definition of prorated section
(2) Revision of Table 1 to include a 25 kV distribution surge arrester and special ratings for rotating
machine protection
(3) Increase in maximum rate-of-rise for front-of-wave sparkover test
(4) Expanded range of currents in the discharge voltage test
(5) Reduced high current test for station surge arresters to 65 kA
(6) Expanded Table 4 to include test values for 550 kV and 800 kV system surge arresters
(7) General revision of pressure-relief test

This standard applies to surge-protective devices designed for repeated limiting of voltage surges on 50- or 60-Hz power circuits by passing surge discharge current and subsequently automatically interrupting the flow of follow current. This standard applies to devices for separate mounting and to those supplied integrally with other equipment