Siemens Auxiliary switch lateral, screw, 2NO current path

The 3RH2921-1DA20 auxiliary switch from Siemens is the perfect addition to power contactors and contactor relays. A key function of the Auxiliary contacts is they transfer data from the circuit to a logic controller, which consecutively gives instructions to the linked devices about whether to turn on or off. This instruction can also be executed remotely.

The screw connection and the two auxiliary contacts (normally closed/normally open) make the auxiliary switch easy to integrate into any switchgear. The laterally mountable auxiliary switches in accordance to EN 50012 can be used only when no 4-pole auxiliary switches are snapped onto the front. If 1-pole auxiliary switches are used besides, the location identifiers on the contactor must be noted.