Allen-Bradley Circuit Breakers — Catalog Numbers, Series, and Replacements

Allen-Bradley Circuit Breaker Series

Allen-Bradley produces several circuit breaker series for different applications:

140M: motor protection circuit breakers (MPCBs) — designed specifically for motor protection with adjustable magnetic trip 140U: UL 489 listed molded case circuit breakers for general distribution 140G: IEC-style circuit breakers for machine tool and control panel applications 1492: supplementary protectors (not UL 489 listed — for use in control panels only, not branch circuit protection)

Understanding Allen-Bradley Catalog Numbers

Allen-Bradley catalog numbers follow a structured format:

140M-C2E-B40: 140M = motor protection circuit breaker series C2 = frame size E = interrupting rating B40 = 4.0A trip setting

140U-D6D3-C20: 140U = UL 489 series D6 = frame size D3 = number of poles C20 = 20A rating

Motor Protection Circuit Breakers (140M)

The 140M series is Allen-Bradley's most widely used circuit breaker in industrial applications. It provides:

Adjustable magnetic trip for motor starting current Manual motor starter function (on/off switching) Overload protection Short-circuit protection

They are used in motor control centers, control panels, and machine tools where a separate overload relay would otherwise be required.

Finding Replacement Allen-Bradley Breakers

Allen-Bradley breakers are available through Rockwell Automation authorized distributors. For hard-to-find or discontinued catalog numbers, AllBreakerSales.com can source Allen-Bradley breakers and identify compatible cross-references.

Call (951) 903-9804 with your catalog number for availability and pricing.

Cross-References to Other Brands

Allen-Bradley 140M motor protection circuit breakers have functional equivalents from other manufacturers:

Siemens 3RV series Eaton PKZM series ABB MS series

However, these are not direct drop-in replacements — verify mechanical and electrical compatibility before substituting.