The 3RB20 and 3RB21 solid-state overload relays up to 630 A with internal power supply have been designed for current-sensitive protection of loads with normal and heavy starting against excessive temperature rises due to overload, phase unbalance or phase failure.
The 3RB20/3RB21 solid-state overload relays are suitable for the overload protection of explosion-proof motors with "increased safety" type of protection EEx e.
The relays meet the requirements of IEC 60079-7 (Electrical apparatus for areas subject to explosion hazards – Increased safety "e").
