3RH1921-1HA22 Classic 3RH1, 2NO/2NC (4), Auxiliary Contact, Snap Front. iemens 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.