Surge Suppressors A selection of Surge Suppressors for use with the SIRIUS range of Contactors Siemens Sirius Range Contactor & Control Relays Siemens control gear for feeders up to 5.5kW. The complementary nature of the devices allows fast and simple assembly, for example, of motor starters and reversers. A perfect match between contactors, overloads, circuit breakers and accessories for the same power ratings provides a uniform panel appearance and the standard widths with no side-by-side mounting derating allows for space saving.