new construction-we’ve got 300 amp service underground service to our house as a CYA situation. We won’t need all of it now. Are we better off using one big panel or two smaller ones?
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If you're OK with spending for two, go with two big panels. Cost difference is negligible in the big picture.
"Let's get crack-a-lackin" --- Adam Carolla
I think you're going to fill up one big one if you've got anywhere near 300 amps worth of usage. I would go with 2 big ones, or one big one and one medium. It depends on your situation. If you've got an outbuilding with significant power needs, or a kitchen that is distant from the main panel, that's where I would use a medium sized subpanel.
zak
should have said up front that the 300 amp service covers ANY possible future needs.
I'll be lucky to need 150-200 amps now.
Well then....
Do a main 200 amp box w/ all your breakers, and an adjacent 100 or 150 amp box for "future".
I'm sorry for my communication skills. I can put in one big box or two smaller ones and use one and leave the other one empty for use in the future.
Partly what you do depends on the layout of the home. If it makes sense to have the two boxes in different parts of the house then install them now. If not, put in something like a 200A box and leave space for another 150A beside it.
If ignorance is bliss why aren't more people
happy?
thanks a lot
I can put in one big box or two smaller ones
Two "smaller ones won't work if you need, as you said in another post, 150-200amps now. 200 amps is a large box.
You need to do the 200 now and add the 100 or 150 somewhere.....or forget the additional box all together.
will do that, thanks alot
It's probably cheaper to put in two boxes, than it would be to put in one 300A box (a non-commodity, pricey item).
Partly it's going to depend on the local AHJ and local codes. With two "main" panels, there must be a disconnect upstream somewhere, and codes will vary as to how this is handled (fused or not, inside or outside) and whether the cable feeding the individual panels must be rated 300A.(Also note that the OP may want to go ahead and install cable for the second panel if it won't be easy to install later.)You can't really feed one panel from the other in this case, since the first panel would be handling all 300A.
If ignorance is bliss why aren't more people
happy?
OK, this is getting more involved than I thought it would. All codes are national since we're out in BFE. Since my boxes won't be opposite my meter, I will have to install an outside disconnect then run my wires inside, (? gauge), to my boxes (one 200 amp and one 100 amp). Does this sound right? I'm doing this as a DIY on my own home that is just "dried in". My knowledge in based on Caldwell's manual which is not in front of me. Thanks a lot
"All codes are national since we're out in BFE. "BFE?Are you saying that there are no codes where you are at? Otherwise codes are actually local and often have local modifications to national codes. Aslo a number of power companys have there own rules up to the panel, specially where there are no codes.I don't have the wording in front of me, but basically the NEC requires overload protection "near" where the power inters the building. That will vary by the AHJ, but I have heard of up to 5 ft, but for some it is 5 inches.If do have to run a distance to the inside panels then you need to have disconnects outside or near where it enters the building. Note some areas are requiring outside disconnects in all cases.If you are going to have AC and/or other large loads near the disconnects. Then you might want to install one weather proof panel and directly feed those loads and next to it a disconnect that feed the other panel as a sub-panel.Depending on what you know that you need now and how big the house is and what your planned future needs are you might go with 200/100, 150/150 or 100/200.
codes are NEC only. Service is buried to temporary box/post 2 ft from the walkout basement wall. I plan on putting the meter and the disconnect right there and passing the line thru the ledger into the basement then around the perimeter to the boxes (about 80 ft.). Will that fly?
Yes, but it is disconnectS. One for each sub-panel. You an have up to 6 as long as they are all in the same place.However, I think that if you are running it 80 that it might be an advantage to go ahead and install one panel at that end of the building and the other 80 ft away.Probably same enough in A) backfeeding the copper from the far end back to the meter end.And you also same the cost of one set of big feeders.
I just re-read Article 230 of the NEC (Services), just to be sure. The two main breakers of the two panels may together serve as the Service Disconnecting Means, so long as the panels are "grouped" together. Individual sets of Service Entrance Conductors to each of the two panels are OK, and the main breaker of each serves as the overcurrent protection for each set. The panel may be inside so long as they are at the point of entry of the SE cables into the building (Point of Entry being defined in the NEC), and they are not in a bathroom.
Of course, local codes and utility requirements may vary from the NEC.