A circuit breaker is an over-current protection device designed to protect main power panel from damage caused by overload or short circuit. There are many well-known circuit breaker companies in the market for their quality such as Siemens, ABB, SquareD, GE, ITE, Cutler-Hammer (or Eaton), Westinghouse, and more... We are able to identify those types of circuit breakers by reading the nameplate or labels. Every circuit breaker has a specific ampere, voltage, fault current interruption rating and descriptions on the label.
How to read the label?
The following example arms to help you read Cutler Hammer Catalog numbering system.
Example: Cutler- Hammer Circuit breaker Vendor Part # CH42B3200K. This is a 3 phase main circuit breaker type CH with the total of 42 circuits is installed in 200A bus amperes in the panelboard size K
CH: type CH 42: number of circuits = 42 B: Main breaker 3: 3 phase 200: 200 bus amperes K : box sizes
The busbar is part of the panelboard that is energized and distributes current to 42 circuit breakers located in the panel. The link down below this paragraph refers to 1 pole and 2 pole circuit breaker. When purchasing 1 pole or 2 pole circuit breaker you will need to know its application. 1 pole circuit breaker is used to provide over-current protection to those circuit that operate on 120V and 2 pole circuit breaker is used to provide over-current protection to those circuit that operate on 240V.