Siemens 3VA5112-4EC31-0AA0 Molded Case Circuit Breaker

Yes, the 3VA51 frame serves as the modern upgrade for legacy 125A ED4 frame breakers. Because the physical footprint is different, you must also purchase a new 3VA5 mounting kit to install it in an existing panelboard.

This feed-thru circuit breaker requires a compatible 3VA5 branch mounting kit to be installed in Siemens P1, P2, P3, P4, or P5 panelboards. It cannot be mounted to the bus without the correct hardware.

As a feed-thru breaker, this unit does not snap onto a plug-on bus. Instead, it must be bolted into the panel or switchboard using a designated branch mounting strap kit, and wires are terminated directly into the provided lugs.

Yes, standard Siemens 3VA5 thermal magnetic circuit breakers are UL listed for reverse feed applications. This allows you to bring the supply power into the load side terminals if required by your panel layout.

The LI code indicates that the thermal magnetic trip unit provides Long-Time (L) overload protection and Instantaneous (I) short-circuit protection.

This unit is equipped with a fixed thermal and adjustable magnetic trip unit. While the 125A continuous overload threshold is fixed, the instantaneous magnetic trip can be adjusted in the field to prevent nuisance tripping from motor inrush currents or other transient loads.

Yes. While commonly used in standard AC electrical systems, this breaker is also rated for DC applications up to 500VDC, making it suitable for certain renewable energy, transit, and industrial DC control circuits.

Beyond Siemens P-series panelboards, this breaker is compatible with Siemens switchboards and motor control centers (MCCs) when paired with the appropriate mounting accessories.