ABB Vmax

The Vmax is ABB indoor medium voltage vacuum circuit breaker built for primary power distribution, compatible with UniGear ZS1 switchgear cabinets. This Vmax adopts integrated monobloc insulation structure with embedded vacuum interrupters, delivering stable arc extinction performance without SF6 gas. The Vmax is equipped with spring energy-stored operating mechanism, supporting local manual operation and remote electrical closing and tripping for flexible site control.

This Vmax covers rated voltage up to 17.5kV, current range from 630A to 2000A and breaking capacity up to 31.5kA. The Vmax is available in fixed and withdrawable truck versions, and the withdrawable Vmax allows racking in and out for inspection and replacement without full cabinet de-energization. It can be matched with various protection relays to implement overload, short-circuit and earth fault protection for transformers, motors and feeders. The Vmax complies with IEC 62271-100 standards and features low maintenance demand and long mechanical service life.

The Vmax is widely used in power plants, industrial substations, mining and water treatment power distribution systems. Standard accessories for the Vmax include auxiliary contacts, under-voltage releases, shunt trips and position signalling units. Many electrical contractors and maintenance teams stock the Vmax as spare breaker for switchgear overhaul and emergency fault replacement of existing UniGear installations.