Can you add circuit breakers by different manufacturers to an electric panel if they fit?
Monday, June 25, 2018
The fact that a brand of breaker that does not match the panel manufacturer will snap into place on the bus bar does not mean that it is alright to use it. The National Electrical Code (NEC) requires any electrical component to be “listed and labeled” for its intended use, which means approved by a nationally recognized rating agency like Underwriters Laboratories (UL) and marked as such, before it can be installed in an electrical system.
There are manufacturers that have gone to the expense of getting UL approval for installation of their breakers in another company’s panels. Siemens, for example, has a type QD breaker that has UL approval for installation in a Square D QO panel, and the photo above shows Square D and Siemens breakers in the same panel.
They are sometimes called “classified breakers” because UL has classified them for use in another manufacturer’s panel. Many manufacturers, but especially Square D, take a dim view of classified breakers and print a statement similar to the following one in their panel installation manuals:
It is beyond the scope of our work as home inspectors to determine whether a particular manufacturer’s breaker is approved for installation in another manufacturer’s panel. But, when we come across an older panel with a jumble of different brands and ages of breakers that we are pretty sure are not all rated for use in that panel, we put a note in the report something like this:
“This panel has circuit breakers in use that are not manufactured by the company that manufactured the panel itself. Panel manufacturers void their warranty when this occurs, it may also void the UL listing of the panel, and could result in property loss or injury due to failure of the equipment. We recommend evaluation by a licensed electrician and repair as necessary.”
We recently saw an extreme example a panel with a collection of mismatched breakers. The panel box shown below was manufactured by General Switch, a company that has been out of business for decades, but only the main breaker at the top was made by General Switch. The rest of the breakers were from Cutler-Hammer, Challenger, GE, ITE, and Square D.
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