The Siemens 3RU2116-1BB0-ZW97 is a SIRIUS thermal overload relay in the Size S00 frame, designed for direct contactor mounting on the SIRIUS 3RT2 series. The relay uses a thermal bimetallic release, so it tracks the motor's true thermal state, not just a fixed curve. It clips directly onto the contactor — no separate DIN-rail footprint needed — and the auxiliary switch is integrated into the housing, saving panel space.
At 24 V it switches 2 A; at 120 V it handles 3 A; at 230 V it's 2 A; and at 400 V it's 1 A. These are the auxiliary contact ratings for the trip-indicating circuit — the note "for message 'Tripped'" means this variant includes a remote signal contact that changes state when the relay trips, so a PLC or HMI can log the fault. Temperature compensation is active from -40 °C to +60 °C, so the trip curve stays accurate across most industrial environments.
The relay carries a substance prohibitance date of 10/01/2009, indicating RoHS compliance per EU Directive 2002/95/EC. It is part of the SIRIUS family, which typically holds UL, CSA, and CE certifications — verify the specific approvals on the nameplate for your jurisdiction, but the platform is globally accepted.