Which breakers are compatible with Cutler-Hammer?

Breakers compatible with Cutler-Hammer depend on the panel family, as Cutler-Hammer produced two incompatible residential systems. For Cutler-Hammer BR panels, which are one inch wide with black handles and are the most common type, compatible breakers are Eaton BR which is the current name for the same product, Cutler-Hammer BR old stock, Westinghouse BR and Bryant BR because those lines were consolidated into Eaton BR, and Eaton CL classified breakers that are specifically labeled as classified for use in BR panels. For Cutler-Hammer CH panels, which are 3/4 inch wide with tan handles and a hook, compatible breakers are Eaton CH, Cutler-Hammer CH, and Eaton CL classified breakers marked for CH panels. In both cases, you should match amperage, voltage, and function such as standard, GFCI, AFCI, or dual function. You should not use Square D QO or Homeline, Siemens, or GE standard breakers in Cutler-Hammer panels unless they are UL classified CL type explicitly listed for that panel, as using non-listed breakers violates the National Electrical Code and can cause overheating due to poor bus contact. The safest rule is BR panels take BR breakers and CH panels take CH breakers, both now sold under the Eaton brand at Home Depot and electrical distributors.