The sirius auxiliary relay 3rh11 is used for auxiliary and control circuits and for ac or dc operation the housing is identical to that of the sirius motor contactors 3rt size s00 uses the same accessories the basic unit has 4 contacts which can be expanded by up to 4 contacts with an auxiliary switch block forced action contacts not restricted by the basic unit to the auxiliary contact blocks climate proof safe to touch to din vde 0106 part 100 high contact reliability at low voltages