Three-pole vacuum safety switch panel with magnetic Gp. driver - switching current loads so that electric working life corresponds o mechanical life for all loads

摘要

A maintenance-free three pole vacuum switch unit has a common magnet driver (3) for switching three-phase current loads. The driver (3) has a constant fixed on and off time. During each switching off the switch members of a selected vacuum chamber (1) open first. The switch members of the other two chambers (2) then simultaneously open a fixed period of time later. The first switch (1) is opened by the driver (3) within 0 to 2 ms before the natural current null point. The other two switches (2) open 5 ms later. The switches (2) which open last, close first, within 2 ms either side of the current null and the first opening switch (1) closes 5 ms later. ADVANTAGE - Increases and equalises the electrical and mechanical life of switches for all types of loads and all on and off currents.