already have two sub panels coming off the main. Want to add another sub about
100 feet from the main due to an out buidling being constructed. Is there a limit on how many sub panels can be added? The main is 200 amp sercvice with one sub at 200 amps and another sub at 70 amps. the third sub would be 100 amp (if allowed).
There is no limit specified but you should do a load calculation to see if you have a large enough service.
You can run directly off the meter in many cases, meaning you are not using the main disconnect (main breaker in original box), IF your new
100A box has it's own MAIN breaker. And since it's an out building, you probably should have a MAIN disconnect in that building. So, I'd buy a 100A box with it's own MAIN disconnect. You may need a separate ground rod(s) for that building too. You'll have to check what is required.But you should check your loads, to determine if your service entrance has enough capacity. For a normal home, 200A should be sufficient, but if this is a business or you are adding a machine shop, you may be lacking.
One other problem. Those wires feeding the sub panels are thick. Will the lugs in the original box have enough room to clamp another cable?
I am on a farm, and there is a main disconnect box on a pole. In that box, are two pull out fuse blocks. Each is 200A (at 240V). In other words I have 400A service. I had cables that fed to the home, the barn, the garage, with each having their own MAIN panel inside those buildings. I built another building (machine shed), and went to install another 100A panel in that building, with it's own MAIN.
That's when I ran into a problem. I was running the whole farm off ONE of those 200A fuse blocks, because I dont run any heavy equipment, and
200A is sufficient. But that new cable would not fit in the lugs. I thought it would be simple to connect to the other 200A fuse block, but that's when I found out that block was cracked and thus faulty. I checked into replacing the whole box with a new breaker box, but it would be costly to have an electrician do the work. (I could do it myself, but the electric company dont allow anyone to do anything where the meter must be removed, unless they are a licensed electrician).The electrician that did the estimate for me, said the old fuse box was still safe and usable, and for $15 he sold me a used fuse block he had in his shed. That solved that problem, and the new building is now connected to the other 200A fuse block.
Typically the sub panel is fed off a breaker from the main panel. And if you're going to try to double tap any terminals, in addition to being able to physically fit, they need to be rated for two wires.
That is called a 200A service. You never have more than 200A flowing.
OK, I missed the two "blocks" part and was thinking two fuses. So you're right, it is 400A.
TWO pullout fuse blocks with TWO 200A fuses in each pullout is 400A. (in other words, FOUR 200A fuses.).
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.