Multi Family Underground Service Question

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Ryan Campbell

Member
Location
Denver, CO
I am doing a proposal for a six unit multi family dwelling with 6 200A interior panels located in each garage and a 125A outdoor house panel located on opposite end of building from outdoor meter bank. I will have a fused disconnecting means at 600A protecting my feeders located with meter bank. I am to run 2" PVC schedule 40 to each interior panel. Do I need to encase my feeders in concrete if I route conduits under garage slabs to each panel? Also do I need to add a disconnecting means when exiting opposite end to feed my house panel? I have read posts that tell me I have to have disconnecting means closest to point of entry so if I run conduits outside of building I would need a discon at every point of entry even if I am protected with my fused disconnect next to meter bank?
 

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
See if I understand correctly.
You will have a 600 amp fused disconnect feeding 7 meter sockets all on the outside of a multi-unit building. From each meter socket you will run underground to a panel in each garage plus a house panel on the opposite end of the building ?
Apartments, condos or town-homes ? (property ownership can often be a determining factor)
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
I am doing a proposal for a six unit multi family dwelling with 6 200A interior panels located in each garage and a 125A outdoor house panel located on opposite end of building from outdoor meter bank. I will have a fused disconnecting means at 600A protecting my feeders located with meter bank. I am to run 2" PVC schedule 40 to each interior panel. Do I need to encase my feeders in concrete if I route conduits under garage slabs to each panel? Also do I need to add a disconnecting means when exiting opposite end to feed my house panel? I have read posts that tell me I have to have disconnecting means closest to point of entry so if I run conduits outside of building I would need a discon at every point of entry even if I am protected with my fused disconnect next to meter bank?

If I understand you correctly, these are feeders, not service conductors. There would not be any requirement for them to be "outside" or concrete encased to make them "outside".
 

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
However, if the feeders are not protected by the 600A main, they will be taps. Therefore if they are not outside, their length will be limited.

Sent from my XT1080 using Tapatalk
 

Ryan Campbell

Member
Location
Denver, CO
yes that is correct 600A Fused disconnect outdoor feeding outdoor meter bank with 6 units meters and 1 house meter then from the meter bank entering multi family dwelling (six plex) underground to each dwelling 200A panel. and 1 underground feed to house panel 125A.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
by the way they are townhomes
Am I clear that you have a breaker in the meter bank for each feeder? That would be the norm and the only compliant way.
But the bigger question for me is your last comment that this is a townhouse. That could change everything. If this is really a town house in the legal sense, as opposed to a condo or apartment building, then all utilities would be brought to each unit separately without passing through another unit. You don't use a meter bank-each unit is treated as a single family dwelling.
 

Ryan Campbell

Member
Location
Denver, CO
I am aware that a townhome would require meter and panel located on unit itself although these are approved stamped drawings maybe not be considering them townhomes . I am just bidding per stamped drawings which calls for meter bank. But I am using main breakers at every units 200a panel.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
I am aware that a townhome would require meter and panel located on unit itself although these are approved stamped drawings maybe not be considering them townhomes . I am just bidding per stamped drawings which calls for meter bank. But I am using main breakers at every units 200a panel.

Ok, sounds like this is not a legal townhouse.
Back to the question of the feeder. You have a standard meter bank with a feeder breaker at each meter?
The feeder has to be protected at the meter bank. You can use MLO Panels (which is the norm) but some like to use a MB panel even though it is protected VIA the feeder.
 

Ryan Campbell

Member
Location
Denver, CO
one line shows a 600A fused disconnect for service entrance conductors, 6 200A 2P feeder breakers at each meter stack and 1 125A breakers for house panel. I am also using main breaker panels at each unit and house panel for homewoners convienance.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
one line shows a 600A fused disconnect for service entrance conductors, 6 200A 2P feeder breakers at each meter stack and 1 125A breakers for house panel. I am also using main breaker panels at each unit and house panel for homewoners convienance.
Ok, you are good to go. These are just feeders then and they don't have to be "outside" the building. The key here is recognizing the difference between a feeder and service conductors. As far as the MB panels, you can certainly do that, but it is not required (unless it is speced).
FWIW, I'm seeing a lot more installs with MB panels that are fed from feeders. In fact, I just had a commercial job with a lot of 200 and 400 amp 3 phase feeder/panels and the engineer insisted on MB panels just because he liked it that way. Nice touch, but it added a lot of cost and much bigger panelboard enclosures in this case.
 

kwired

Electron manager
Location
NE Nebraska
Ok, you are good to go. These are just feeders then and they don't have to be "outside" the building. The key here is recognizing the difference between a feeder and service conductors. As far as the MB panels, you can certainly do that, but it is not required (unless it is speced).
FWIW, I'm seeing a lot more installs with MB panels that are fed from feeders. In fact, I just had a commercial job with a lot of 200 and 400 amp 3 phase feeder/panels and the engineer insisted on MB panels just because he liked it that way. Nice touch, but it added a lot of cost and much bigger panelboard enclosures in this case.

Another possibility is having the 600 amp main, the seven meters with no overcurrent devices making each line to each panel a feeder tap. They will have length restrictions though, except if installed outside the building (which can include under the slab) as outside feeder taps can be unlimited length. But once it enters the building at the load end you have to pay attention to length inside.

Maybe not all that common of an install but is acceptable.
 
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