Letter Re: Mechanically Interlocked Panel


I’ve had a “prepper” mindset for most of my life (I’m in my late 40’s) and find the information contained in your blog to be some of the best on the web. I try to read the blog often but have never submitted a piece based on my experiences. Today I was perusing SurvivalBlog when I realized that I have some information that may be helpful to your readers. It will definitely save anyone considering wiring their home for a back-up genset considerable money as well as simplify its operation. One who is considering this project typically will read that the only safe way to wire a back-up generator to your service is through a transfer switch. There is another way that I contend is safer, much less expensive, and simpler.panel It’s called a mechanically interlocked breaker panel cover. Basically how it works is this: a receptacle is installed outside the home where the generator is plugged in. That receptacle is then wired to a breaker in the panel (mine is a 30 amp breaker). This breaker is typically located in the uppermost right slot on the panel. This breaker can not be thrown to the “on” position without lifting an integral gate on the panel cover that can only be lifted by shutting “off” the main breaker. Once this is accomplished, you simply switch whatever circuits you DON’T want off by their breakers. Then you can start the generator. It is foolproof and positive, and the only part that needs to be purchased is a new panel cover with the interlock. The cover is much less than $50. The savings are multiplied by the ease of installation. Another benefit to those who may have limited space near their panel to mount a common transfer switch is that this product takes up no more space than your existing electrical panel.

“Back feeding” a panel by any other means is dangerous to utility workers and possibly firefighters who would respond to your residence. I submit this information as a professional firefighter and have had mine installed in my primary residence by a co-worker who is also a Master electrician. It meets all existing electrical codes and is as simple as throwing a switch. The only drawback that I can see is that it is purely manual. I hope your readers can benefit from this information and save substantial cash over a commercially available transfer switch. – MM