What it is and what it fits
The Siemens 3RB2913-0AA1 is a stand-alone installation base — the mounting and wiring foundation for a 3RB20 or 3RB21 overload relay in Size S00. It carries screw-type terminals on the main circuit and is designed for panel or enclosure mounting where the relay is not clipped onto a contactor but installed separately.
Sourcing
The 3RB2913-0AA1 is sourced to order through independent distribution. Availability and current pricing are confirmed at quote time against an RFQ. For volume or scheduled buys, the successor 3RU2916-3AA01 is the recommended path.