Surge arrester

IEC 60617 (single-line diagram symbols)

Drawn as

A rectangle with a downward arrow inside, connected between the conductor and earth.

Meaning

Protects transformers and cables from switching and lightning surges. Becomes surge-arrester in an outdoor substation or at a transformer; inside switchgear it is not modelled separately.

Variants

Older legends show a spark gap (two arrows tip to tip)