Electrical Ground Symbol

The electrical ground symbol represents a connection to earth potential (0 volts reference) in electrical and electronic schematics. There are several variants: the earth ground (three horizontal lines of decreasing length), the chassis ground (three diagonal lines), and the signal ground (a triangle pointing downward). The earth ground symbol is standardized by IEC 60417 (symbol 5017) and ANSI/IEEE 315. In circuits, grounding provides a reference voltage, safety path for fault currents, and protection against static discharge.

Standardized by IEC 60417 (symbol 5017) and ANSI/IEEE 315. The concept of electrical grounding dates to the 19th century.