backfeeding

[cdavis7254]

I keep getting told that backfeeding the main panel is limited to 20% of the panel rating, for example, a 200 amp service can have a maximum 40 amp backfeed breaker. None of them can give the the code that they are referencing, and I can't find it.

 

[SEO]

I haven't heard of it either. Without a code reference what are they basing their coments on?

 

[LarryFine]

I would think that the only limitation is the stab-rating limit, typically 100a.

 

[iwire]

I keep getting told that backfeeding the main panel is limited to 20% of the panel rating, for example, a 200 amp service can have a maximum 40 amp backfeed breaker. None of them can give the the code that they are referencing, and I can't find it.

That is true if your backfeeding a panel that already has full size utility feeder and your adding a solar array. This can be found in 690.

 

[cdavis7254]

OK, is sounds like they are rewording 690.64(B)(2). As 120% of the 200a panel is 240, so the max OCPD would be 40a. (yes, it is a solar array issue)

 

[cdavis7254]

I've re-read that section of 690 a couple of times today. If I'm reading it correctlly, I only need to size the busbar in the distribution panel for the 120%.