How to Identify a Replacement Circuit Breaker in 5 Steps

Breaker failed and the label is half burned off? Before you order, work through these five checks — they are what our team asks for on every identification request.

1. Frame and series

Molded case (e.g. Eaton Series C, Siemens 3VA) or miniature DIN-rail (ABB S200, Schneider Acti9)? The frame determines the physical size and mounting.

2. Poles and rated current

Count the poles and read the amperage on the toggle or label — e.g. 3-pole, 40A. Never substitute a lower breaking capacity than the original.

3. Tripping characteristic

B, C, D, or K curve matters for inrush loads. A motor circuit on a B-curve breaker will nuisance-trip.

4. Breaking capacity (kAIC)

Match or exceed the original interrupting rating. This is a safety value, not a suggestion.

5. Accessories

Auxiliary contacts, shunt trips, and undervoltage releases are often ordered separately — check the old breaker before it leaves the panel.

Still unsure? Send us a photo of the breaker and its label and we will identify it for you.