Can I have 2 Main Breakers on one 220V incoming line

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Joe 78733

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This may see a bit strange, but here goes. I want to connect my generator to my house using a 50 amp power inlet box with a interlock on my power panel. The set up is as follows at my house: The electric meter is at the street in a box that also incorporates a 200 amp main breaker.

This then runs to a panel on the outside of my house with several breakers in it for AC, Electric stove and a few outlets. It also has a Sub Panel breaker that then runs into the house for the main items, i.e. lights, outlets etc.

I would like to do the following:
1. Add a 200 amp breaker on the panel box outside where the main power comes into the panel box, (Picture attached).
2. Move the 70 amp sub panel breaker down and add a 50 amp breaker for the portable generator
3. Install a interlock for the new 200 AMP breaker and the generator breaker.

If I do this, I will then have two 200 amp breakers on the incoming main line. In theory this seems OK as either one could trip and shut down my incoming power. What I don't know is it OK to have the two breakers on the line. I can not remove the breaker at the street very easily so I would rather not touch that, just add the new 200 amp breaker. Thoughts?
 

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There is no problem having two similarly rated breakers in series. If there is an over-current, either could trip. You won't know in advance which one is going to trip.
 
You need a device known as a "generator transfer switch". Well worth the money. They save your house from burning down, kids from getting electrocuted and you from watching either happen.

 
That's how I have done it.



Note how the actual transfer contacts are mechanically and electrically ganged for general safety. Just make sure the contactor(s) are rated for your desired current and another feature is that you can't back feed into your mains supply. The above is my old 100 Amp service switch which was used with a 13 KW generator. The new switch is 200 amp service with a larger generator set. You make no mention of your genset power?

Ron
 
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