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AssuredElectrical, Master Electrician
Category: Electrical
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Experience:  Contractor-42+ Years in the ElectricalTrade
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Got a nasty little problem. Want to install a 6kw solar PV

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Got a nasty little problem. Want to install a 6kw solar PV system into my existing 100 amp service breaker box. The NEC ratings say that I can only put a 25 amp back fed breaker from the inveter into the box, but I need 40 amps. I can upgrade the breaker box to 125 amps (max), and replace the 125 amp main breaker with 100 amps. Then I'll have up to 50 amps of back feed the breaker box from the inveter (120% of 125 amp bus bar = 150 amps). Problem is, the 120% rule only applies if the back fed breaker is at the opposite end of the bus bar from the main breaker. I can only find 125 amp breaker boxes that have the main in the middel of the bus bar, so I am limited to only 100% total feed to the box, or 25 amp back fed breaker. Does anyone have any suggestions on how I could get this done, given all of these issues?
Welcome. My name is XXXXX XXXXX would be glad to assist.

So, you want a 125 amp rated panel with the 100 amp main breaker at the top end of the buss, so you can install the Back feed at the bottom, is this correct?
Customer: replied 4 years ago.
Yes. Can't find a 125 A Penelope that isn't center fed.

I do not see many center fed panels.

How about these? Mains at the top and then add your feeder breaker to the bottom?
125 amp Ratings and swappable breakers.

These are for seeing the make and model numbers.
Then they can be purchased from your choice of supply stores or distributor.



Or you can get a main lug panel rated 125 amps, install a 100 amp for your main at the top and then the feeder at the bottom.


Main Breaker for the Panel above

Either work for you?
AssuredElectrical and other Electrical Specialists are ready to help you
Customer: replied 4 years ago.
Thanks for the suggestions. Couple of issues still. The meter and box are located outdoor, and the meter is "adjoined" to the breaker panel. Since this is the case, I was planning on replacing the meter socket too. I was thinking that thery must sell a "service disconnect switch" and maybe just mount that outside, then I could mount the breaker box inside. The problem I see with that is how am I going to route/extend all the wires in the present, outside box to the new box?
Ok, thanks.

I understand why the situation since it is an outdoor combo unit.
Little more difficult.
Let me see what all I can round up. Has to be one out there with a 100 amp breaker main but the buss rated for 125.

Will post as soon as possible, thanks
Ok, check this one, should do the job.

CLICK HERE for an outdoor surface mount combination unit, having up to 24 circuits

CLICK HERE to see the 125 amp breaker it comes with, Identical plug in style to the 100 below

CLICK HERE for the 100 amp breaker same as the one the unit has installed

The combo has 12 spaces for standard size breakers, or 24 spaces for the tandem style
Total 24 circuits.
Customer: replied 4 years ago.

$499. Ouch. I've looked and looked for something else, but can't seem to find anything.


I think we are done. Thanks for everything. You've been really helpful.


Best Regards, Tom