erottimet

Erottimet is a Finnish term used in electrical engineering to refer to electrical disconnectors or isolators. The word derives from erott- meaning to separate, and in Finnish technical literature erottimet describe devices that electrically separate parts of a circuit to ensure safe maintenance and a clearly visible isolation.

In substation and line equipment, erottimet are installed to create a clearly de-energized section by physically separating conductors. They are typically opened only when the circuit is de-energized and may include manually operated or motorized variants, often with interlocks to prevent accidental closure while energized. Erottimet are designed to provide a visible gap and are not intended to interrupt large fault currents; that function is performed by circuit breakers or fuses. Their primary purpose is to guarantee safety and to aid in verification that isolation has occurred during maintenance or testing.

Types commonly used include outdoor air-break disconnectors and indoor isolators, engineered to withstand environmental conditions and to support safe maintenance operations. The technical guidance for erottimet follows general switchgear standards and practices, aligned with national and international norms for high- and medium-voltage equipment. The term is mainly used in Finnish electricity infrastructure contexts; in English-language literature the same concepts are usually described with terms such as disconnectors or isolators, depending on context.