320/400A Service to House & Outbuilding... "best" way?

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ddecart

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New Construction. 320/400A service.

I plan on running two 200A service panels in the house, immediately inside the house from the meter.
I also have an outbuilding in which I wish to place a 100A panel (overkill, but better to do now than later)

Original Plan:
Double-lugs on meter
200A Panels in house
100A from house panel to outbuilding

However... outbuilding will be ready for power before the house walls are even up.

New Plan = ??
It is best to set a 100A disconnect outside, adjacent to the meter, and feed the outbuilding straight from there?
In that case, does this pose issues for how this whole thing gets grounded with part going through an intermediate disconnect and the rest not?

btw, no grounding/bonding bar or lug on the meter box at all. Configured as such:
Meter_Wiring.jpg


Thanks
Dave
 
You can use an all in one meter combo or set a 400 amp meter base with 2- wp trailer panels with feed thru lugs. You can then feed thru to the inside and then go to the barn from one of the outdoor panels. This also allows flexibility as to where you can install the interior panels and it can also makes it easier for future power needs on the outside.

The other option is to put the service at the barn but that will cost a lot more money....

I assume you mean that the exterior walls will be ready for the service????? If not then you have to make it work from the barn or on a post in the yard
 
Thanks Dennis

I have the 400A meter base in hand, so I'll go with that.
The run from the meter location to the barn is roughly 100'. Barn walls are up, but not the trusses. House is a basement right now and walls won't be up before the electric service is in.
Meter is on the back/side corner of the garage nearest the driveway (i.e. convenient for reading, but out of sight). Planning on putting both 200A service panels in the garage, since it seems as practical as any other location, and won't drive a switch at the meter location. For now, I'll mount the meter to unistrut, which will then be attached to the basement wall. So it'll be "freestanding" a couple of inches from its ultimate location. Will just need to remove the struts and mount it to a plate on the wall.

Before then, and long before I have any of those panels in place, I'm expecting to have the meter placed and be running on a temporary panel mounted to the side of the meter enclosure. This will run whatever is needed for construction, plus provide a 30A RV connection since I'm living on-site in a travel trailer during construction.

So it'll go:
Near term: Meter mounted on struts, mounted to basement wall, temporary panel serving construction and RV. Have a 125A 8 space main lug for this.
Short term (~2 months): 100A barn panel comes online, temporary panel goes away. Barn gets RV hookup.
Long term: Dual 200A panels in garage and something feeding to the 100A panel in the barn

Make sense? I can go whatever way makes sense in the end, which is why I left the interim steps off in my initial post, but if it dictates something making more sense now vs later, I'm all ears.

Dave
 
ddecart said:
New Construction. 320/400A service.

I plan on running two 200A service panels in the house, immediately inside the house from the meter.
I also have an outbuilding in which I wish to place a 100A panel (overkill, but better to do now than later)

Original Plan:
Double-lugs on meter
200A Panels in house
100A from house panel to outbuilding

However... outbuilding will be ready for power before the house walls are even up.

New Plan = ??
It is best to set a 100A disconnect outside, adjacent to the meter, and feed the outbuilding straight from there?
In that case, does this pose issues for how this whole thing gets grounded with part going through an intermediate disconnect and the rest not?

btw, no grounding/bonding bar or lug on the meter box at all. Configured as such:
Meter_Wiring.jpg


Thanks
Dave
Click to expand...
Original plan is code compliant but your more then enough 100 amp feed to the outbuilding could take away some capacity needed in whichever panel you connect it to if down the road there is more load added.

New plan - one problem with mounting a service disconnect on the exterior of the house and the two house service disconnecting means inside the house is you now have multiple service disconnecting means at one structure and they are not grouped in one loctation.

My best plan is to just feed service conductors from the meter socket or a pull/splice box if you need more room for connections to the outbuilding instead of putting a disconnect in or on the house.

Next best plan if the other plan doesn't work for some reason is to put in a single 400 amp service disconnecting means and run feeder taps to the two house panels and a feeder tap to the out building. Outside feeder taps can be unlimited length.
 
kwired said:
Original plan is code compliant but your more then enough 100 amp feed to the outbuilding could take away some capacity needed in whichever panel you connect it to if down the road there is more load added.

New plan - one problem with mounting a service disconnect on the exterior of the house and the two house service disconnecting means inside the house is you now have multiple service disconnecting means at one structure and they are not grouped in one loctation.

My best plan is to just feed service conductors from the meter socket or a pull/splice box if you need more room for connections to the outbuilding instead of putting a disconnect in or on the house.

Next best plan if the other plan doesn't work for some reason is to put in a single 400 amp service disconnecting means and run feeder taps to the two house panels and a feeder tap to the out building. Outside feeder taps can be unlimited length.
Click to expand...

Makes sense. Remove the temp panel and either install a triple lug on the meter box and run to 1) 200A house panel 2) 200A house panel #2 3) 100A barn panel. OR replace temp panel with a junction panel and essentially do the same from in there. Nothing gets switched before it enters a structure, each structure is grounded, and everything is happy. Works for me.

The former would mean finding triple lugs for the meter. The latter means finding splice box and appropriate connectors. Same result really, except if one offers a cost-effectiveness benefit over the other.
 
electrofelon said:
Do you really really need a 400 amp service? 97% of the time it's a waste of money. 230.40 exception 3 is your friend here.
Click to expand...
Electric heat or instantaneous water heaters can change that, but otherwise if you don't have those I agree 200 amps is usually plenty for most dwellings

A 50 bedroom mansion is a hotel not a single family dwelling - JMO.
 
Update

Update

Ahhhh.... the best laid plans....

Laughing at my optimism from when I first posted this last fall. Both the house and outbuilding are enclosed and roofed, but much later than I had anticipated. Neither the house nor outbuilding electric has been hooked up, much to my chagrin, but I'm getting close (finally).

What I ultimately decided on was:
a) 200 Amp panel in the garage, near the meter, serving 1/2 the house and basement workshop
b) 200 Amp panel in the garage, near the meter, acting as a disconnect for the remote panel serving the other 1/2 of the house, and the feed to the outbuilding

Where I am now:
a) is installed as planned and wired. Serves the garage, the 2 bedrooms/baths, and living room over the garage, and the shop below the garage (100A sub panel). Includes a 60Amp tankless water heater for the garage floor, and a standard tank heater.
b) is installed, about a 75' cable run from the meter location. Rest of the house is wired to it. Kitchen (all electric), Laundry (electric dryer), Office, HVAC, main water heater, etc..

Remaining:
Install the disconnect for b) and run the ~75' of SER. (plus run the feed to the outbuilding)

But.....
I'm second guessing this "Panel as a disconnect" strategy. 200A panel with nothing but 2 big breakers in it. Looks a little silly. And in case you haven't been looking, 200A breakers aren't exactly cheap.

Would it not make more sense to ditch that panel and install a 200A 8-space panel with feed-thru lugs? Use the feed thru to the basement panel. Toss in the 100A breaker and make the run to the outbuilding.

Then it's a question of whether it goes outside, next to the meter, or inside, next to the other panel. It's an "outdoor" enclosure, so it'll look different, but so what.

~Dave
 
The feed thru lugs are fine but it needs to be next to the other panel. Service disconnects must be grouped. You may find that the price for the feed thru is a bit higher. It would be a low demand item in this area and considerably higher $$ than the standard 200 amp residential panel.
 
ptonsparky said:
The feed thru lugs are fine but it needs to be next to the other panel. Service disconnects must be grouped. You may find that the price for the feed thru is a bit higher. It would be a low demand item in this area and considerably higher $$ than the standard 200 amp residential panel.
Click to expand...

I can order a Square D feed thru for under $150 from Lowes (nonstock item). Cheaper than the 200A branch breaker alone. Saving money isn't a bad thing!
 
ddecart said:
I can order a Square D feed thru for under $150 from Lowes (nonstock item). Cheaper than the 200A branch breaker alone. Saving money isn't a bad thing!
Click to expand...

Them 150 and 200 amp breakers are sold in higher volume already installed as main breakers in a panel.

If you are going to have a panel that actually accepts multiple 200 amp breakers, those aren't as common and not as high of volume production item, expect they will cost more even if they accept the exact same breaker as the main breaker in a typical "loadcenter".
 
Seems like the plan where the 2 house panels and the garage panel were all fed from the meter base was the simplest.
 
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