Running raceways from meter bank to apartments in high rise building

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Tainted said:
I see, also, instead of MC cable could I just use EMT and stack multiple struts and have architect enclose them with a wall riser?
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That's what we would do. Remember if you use a wireway the removable covers will need to be accessible after installation.
 
infinity said:
That's what we would do. Remember if you use a wireway the removable covers will need to be accessible after installation.
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Is there a limit of how many I can stack the struts? I've seen 2 stacks but hardly ever seen 3. If I go ahead with the strut method, I know I would have to support the conductors as per NEC 300.19, what methods are good for this application? If for whatever reason I need to use the wireway method how would I be able to support cables per NEC 300.19 as well? Thanks!
 
You can easily go three racks deep. For support you'll need a junction box every so many floors depending on the condcutor size along with some type of support method. We always use chock bushings and wooden chocks.
 
Tainted said:
Is there a limit of how many I can stack the struts? I've seen 2 stacks but hardly ever seen 3. If I go ahead with the strut method, I know I would have to support the conductors as per NEC 300.19, what methods are good for this application? If for whatever reason I need to use the wireway method how would I be able to support cables per NEC 300.19 as well? Thanks!
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There isnt any limit. Obviously if you use something like threaded rod and coupling nuts its going to get pretty sloppy the more you cantilever out. I guess an inspector could make a call from various code sections if he thought it wasnt strong enough.

300.19 could definitely make a cable wiring method more appealing. You would get into needed cleats or bushings to support the conductors with pipe and wire or wireways.
 
So there's nothing I see in the article on MC cable about vertical supports. Is the outer armor always sufficiently tight to the conductors inside to provide frictional support to the conductors? Because any external straps are only going to directly support the armor.

Cheers, Wayne
 
electrofelon said:
There isnt any limit. Obviously if you use something like threaded rod and coupling nuts its going to get pretty sloppy the more you cantilever out. I guess an inspector could make a call from various code sections if he thought it wasnt strong enough.

300.19 could definitely make a cable wiring method more appealing. You would get into needed cleats or bushings to support the conductors with pipe and wire or wireways.
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do you have a picture or spec of the supports used for 300.19? I tried looking for it to see but I can’t find it anywhere.
 
Tainted said:
But this only shows supports for conductors coming out of conduits, what if I have 40 #4 THHN conductors vertically going up in a 6x6 wireway riser?
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Full disclosure, I have never had to support vertical runs of cables, I am sure there are people on here who can offer first hand advice, but there are cleats/clamps you can attach to the wireway, or even fastening a piece of strut and tying them to the strut would seem to be acceptable.
 
You stated high rise….how many floors?
Are you sure this should be your first high rise project?
You don,t seem to have any design details resolved as of yet.
Why are you limiting yourself to only meters in the basement, is the utility making the call on this?
Can you go with electronic metering…owner bills tenants monthly.
Have you considered 3p-4w risers that rise up through multiple floors and tap off 3w for each apartment. I have seen this done on 3-9 apartments being served from one 4w riser.
 
electrofelon said:
Full disclosure, I have never had to support vertical runs of cables, I am sure there are people on here who can offer first hand advice, but there are cleats/clamps you can attach to the wireway, or even fastening a piece of strut and tying them to the strut would seem to be acceptable.
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Ok, i know these questions I asked seems redundant but as long as I have 2 options available to present to the architect
MyCleveland said:
You stated high rise….how many floors?
Are you sure this should be your first high rise project?
You don,t seem to have any design details resolved as of yet.
Why are you limiting yourself to only meters in the basement, is the utility making the call on this?
Can you go with electronic metering…owner bills tenants monthly.
Have you considered 3p-4w risers that rise up through multiple floors and tap off 3w for each apartment. I have seen this done on 3-9 apartments being served from one 4w riser.
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For privacy reasons I don’t want to disclose how many floors but it’s a highrise building as defined by NFPA. The building I’m working on is very old like in the 1920s, it has metering riser in egress stairs and I’m basically renovating the electrical infrastructure to meet all code and install metering in the basement. This is my first highrise electrical upgrade project so I’m somewhat lost but I’m getting closer to solutions.
 
I’m sorry for this but I do not think you are getting closer.
If you but together some crazy design with wire way going up through the building, I don’t want to be you when ALL the bidders embarrass you and I turn your client when they state how cost crazy this is.
Suggest you work through the load calls per unit type…per floor, etc. and get in a conf room with at least 2 of the favored bidders and get feedback And ideas.
If you can’t bring anyone in because of secrecy…then I don’t know how to advise you further.
 
MyCleveland said:
I’m sorry for this but I do not think you are getting closer.
If you but together some crazy design with wire way going up through the building, I don’t want to be you when ALL the bidders embarrass you and I turn your client when they state how cost crazy this is.
Suggest you work through the load calls per unit type…per floor, etc. and get in a conf room with at least 2 of the favored bidders and get feedback And ideas.
If you can’t bring anyone in because of secrecy…then I don’t know how to advise you further.
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Just want to clarify, this bright idea of putting a wire trough riser wasn't my idea. My supervisor is a mechanical engineer and he suggested it I warned him about it and all the limitations. I just wanted to know my options whether it be wireway or conduit raceway because my supervisor told me to present all the options to the architect. FYI, I already calculated all the demand load of dwelling units for each floor and entire building.
 
MyCleveland said:
Back to why meters only in basement….
Architect won’t give up any floor space for a stacked riser?
Can you consider the 4w riser path?
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architect is able to give up some space, he just needed to know how much space I would need. So we would need 2 risers (north and south). Suppose the north has 50 units and the south has 90 units and all are 3 wire units, I would need to figure out how much space I would need for the north and south risers. The 4wire riser path is a no no, we are only limited to the basement for metering. There isn't even enough space for meters to be in each floor without having it in an egress pathway. So we are limited to the basement only.
 
You can do the electronic metering without meter stacks…just distribution panel with the apt breakers and electronic metering integral.

If you go 4w riser…same thing, no meter stacks, just electronic module at each apt panel. Sales reps can walk you through your options.

If you stay in the basement using meter stacks, how many mains or sub-feeder CBers?
I think the largest meter stack bus is 1200A, with I believe a 1600A main you would put in the middle feeding 1200a bus meter stacks (6 per stack) going left and right.
Do you have enough ceiling height to get all these feeders out the top and create a path to where you finally start rising up….90 feeders + the other 50.
Infinity: can he route all 6 per stack, say 5 stacks adjacent (approx 15” wide each). Seems like to much material in a small window.

Just things to think about, hope it helps in some way.
Was not trying to be critical on the wire way idea, just trying to advise you not to waste time.
 
I have never found sub-metering to be worth it. At first it might seem worth it, but when you factor in all the metering equipment and the hassle forever on the property owner it just doesn't pan out. Furthermore it can be legally sticky in some states .
 
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