Siemens P4250 Molded Case Circuit Breaker

This breaker is designed specifically for classic Pushmatic load centers. It features a proprietary bolt-on design and will not fit standard plug-on or modern bolt-on panels from other product lines.

Yes, the Siemens P4250 is a direct drop-in replacement for obsolete Bulldog, ITE, and Gould P250 circuit breakers. It allows you to safely maintain existing Pushmatic enclosures without a full panel upgrade.

It installs using a secure bolt-on connection unique to Pushmatic panels. This bolted joint ensures a reliable electrical connection to the bus bar, unlike standard snap-in designs.

The terminal lugs accommodate 8 AWG to 4 AWG wire and are rated for both copper and aluminum conductors. Always apply an approved oxide inhibitor when terminating aluminum wire and torque to the manufacturer specifications.

The fixed thermal-magnetic (LI) trip unit provides two layers of protection. The thermal element responds to sustained overloads by heating up and tripping the breaker, while the magnetic element provides instantaneous tripping when a high-current short circuit is detected.

While 10kAIC at 240V AC is standard for many older residential Pushmatic panels, you must calculate the available fault current from the utility transformer. If the available fault current exceeds 10,000 Amps, this breaker cannot be safely installed.

Unlike standard toggle breakers, Pushmatic breakers like the P4250 use a unique push-button mechanism to manually open or close the circuit. The button provides visual indication of the breaker status.