Siemens SIRIUS Overload Relays
If overload, phase imbalance or phase failure occur in the main circuit, then it doesn’t look good for the connected load – that is if you are not reliably protected. With SIRIUS overload relays.
SIRIUS overload relays fulfill every requirement
For standard applications:
3RU11 thermal overload relays up to 100 A with tripping CLASS 10
3RB20 solid-state overload relays up to 630 A with tripping CLASS 10 or CLASS 20
3RB21 solid-state overload relays up to 630 A where tripping CLASSES 5 to 30 can be set and a ground fault detection function that can be enabled
For high-feature applications:
3RB22 solid-state overload relays up to 630 A where tripping CLASSES 5 to 30 can be set, a ground fault detection function can be enabled, a PTC sensor can be connected as well as monostable auxiliary contacts
3RB23 solid-state overload relays up to 630 A where tripping CLASSES 5 to 30 can be set, a ground fault detection functioncan be enabled, a PTC sensor can be connected and bistable auxiliary contacts
The overload relays are certified according to ATEX and thus suitable for motors with "increased safety" type of protection EEx e.