'approved raceway'

[randii]

My inspector black-flagged my home-built wood runners but gave me props for not just threading the conductors through the rafters (his term 'nailbait' was kinda funny).

He suggested i use an 'approved raceway' but I'm having some issues finding affordable product for spanning ~50' of unfinished attic/rafters between my main panel and sub-panel.

Anyone got any suggestions or 'approved' workarounds? I really don't wanna have to spring for a new run of romex-on-steroids... IIRC about an 80' total run of 125amp service.

Related discussion: http://www.pirate4x4.com/forum/showthread.php?t=176617

Randii

[fivetenben]

My inspector black-flagged my home-built wood runners but gave me props for not just threading the conductors through the rafters (his term 'nailbait' was kinda funny).

He suggested i use an 'approved raceway' but I'm having some issues finding affordable product for spanning ~50' of unfinished attic/rafters between my main panel and sub-panel.

Anyone got any suggestions or 'approved' workarounds? I really don't wanna have to spring for a new run of romex-on-steroids... IIRC about an 80' total run of 125amp service.

Randii

Third hand info so take it as such:

A buddy of mine overheard a guy talking to an inspector about his detached garage addition. He got around the electrical inspection like this: He put an big-ass outlet next to his panel that was inspected and aproved. Then "plugged in" the garage wiring to that outlet. The inspector said "thats a pretty chickenshit way to do it", but didnt make the guy tear it out. Sounded like everything was to code, but the guy didnt want to pay the fees.

[steveh]

Use schedule 40 conduit.

[Jeepaholik]

Run it in some EMT....

[randii]

I may be dreaming, but I was hoping for an 'open' raceway, not conduit... because I don't want to downrate the conductors (though IIRC, I had ampacity tolerance to to so) and I don't want to pull the connectors (because I am LAZY).

Lazy old me is hoping for easy-to-assemble tray-style raceways that I could just lay the existing conductors into without disconnecting. Oh, and since I'm dreaming, it needs to be cheap and come with self-installation gnomes. :rolleyes:

Randii (prolly just gonna have to pull it in big conduit)

[roundeye]

Schedule 40 PVC is about the easiest and most cost effective solution. You could use electrical gutter like your talking about but it won't come with the gnomes and it's pretty expensive and time consuming to install.

I also saw a job where someone used Unistrut which is a U shaped channel and put the SJ cord in it. It passed but is not considered an approved raceway.
Give me a call Randi and I may be able to give you a hand.

[jasonmt]

I may be dreaming, but I was hoping for an 'open' raceway, not conduit... because I don't want to downrate the conductors (though IIRC, I had ampacity tolerance to to so) and I don't want to pull the connectors (because I am LAZY).

Lazy old me is hoping for easy-to-assemble tray-style raceways that I could just lay the existing conductors into without disconnecting. Oh, and since I'm dreaming, it needs to be cheap and come with self-installation gnomes. :rolleyes:

Randii (prolly just gonna have to pull it in big conduit)

2"x2" solid style galvanized channel runs about $4/20' section up here. Should run you under $25 to do 50' including the raceway connectors.

[Gummi Bear]

Sorry pal, but you don't have a ton of options on raceway.

Do you have individual conductors or a SE cable (big romex)?

If you have individual conductors, go ahead and put them in PVC schedule 40 ELECTRICAL RATED. The gray stuff. Using plumbing PVC will make some inspectors furious. It's easy to work with, especially if you'll use premanufactured bends and fittings.

Don't forget to strap it often, it'll sag in the summer heat.

If you are pretty slick with running pipe, measuring and fitting, you can do EMT, but with the cost of steel, it's getting pretty expensive (I pay nearly 4 times as much today as I did a year ago for conduit)

I'd not advise anyone who isn't an industrial hand to run GRC, IMC or ARC conduit. You have to have some experience to do it right (and it's expensive when you screw up)

Gutter can be had in sections, but is cost prohibitive. I've done some pretty elaborate gutter systems before, and they are nice, but you need to keep in mind that you can only fill one to 20% of its cross sectional area.

Wiremold makes some way cool stuff, but it's super expensive. About using the channel, it has to be the proper 'unistrut' type of channel (which you won't get for cheap) and it also has to have the approved cover) I think it's probably still too small for your 125A feeder.

Per the 2002 NEC(t310.15-B-6), you can use wire as small as #2 ga THHN, THHW, RHW, XHHW, SE, USE to feed a 125A panel and still be within code for your current carrying conductors. While you can derate your neutral (to keep costs down), I always advise against it. Keep that sucker full sized.

[randii]

This is a prime example of how hurrying the job causes more extensive rework and more cost later. :rolleyes: I could have just slid PVC tube over the conductors and glued it as I installed it... and I even knew better at the time. :shaking: I may still just disconnect at the sub and back-pull the conductors to the main...

There's definitely more cable tray and wire gutter out there than last time I checked -- seems like before 2000, this was an industrial-only application? I guess I'll swing by a couple of the local electrical supply houses after SEMA. Even without installation gnomes, wiring trough/gutter should be pretty simple... Maybe I can find an in-stock product that will work ... no pullboxes or complex routing, it is a straight shot across the attic with a diagonal across the garage rafters and a straight drop down to the subpanel. Oh, and double-check with the inspector before I but/install to make sure he won't downrate the conductors or make me buy tray-rated cables or something odd like that.

Thanks for the tips... and Bruce, I may give you a ring after SEMA.

Randii

[randii]

Sorry pal, but you don't have a ton of options on raceway.
Do you have individual conductors or a SE cable (big romex)?

Yeah, see what happens why I half-ass an install? :rolleyes:

FWIW, I have individual 4 AWG THHN conductors connecting the 200A-rated main and the 125A-rated subpanel (FWIW, both are breakered at 100A).

Randii

[Gummi Bear]

Yeah, see what happens why I half-ass an install? :rolleyes:

FWIW, I have individual 4 AWG THHN conductors connecting the 200A-rated main and the 125A-rated subpanel (FWIW, both are breakered at 100A).

Randii

Protected at 100A, you're good to go on the #4. Go ahead with the PVC, you should be able to do it pretty quickly (less than a 6 pack) and it shouldn't cost too darn much. I'd guess that PVC raceway will cost you about 50-60 bucks for the conduit, elbows and fittings.

Good luck, podnah.

[jasonmt]

....Gutter can be had in sections, but is cost prohibitive. I've done some pretty elaborate gutter systems before, and they are nice, but you need to keep in mind that you can only fill one to 20% of its cross sectional area.

Wiremold makes some way cool stuff, but it's super expensive. About using the channel, it has to be the proper 'unistrut' type of channel (which you won't get for cheap) and it also has to have the approved cover) I think it's probably still too small for your 125A feeder.....


The tray/gutter I am thinking about looks like the attached picture and is not very expensive. Due to my location my familiarity with the NEC is not as good as you who have to abide by it.

So allow me some questions to satisfy my curiosity??

(392.6) Cable tray covers are required to provide protection for cables only where cable trays are subject to mechanical damage?

(392.3) Would THHN be allowed to be used in a tray installation?

(392.10) States that single conductor cables in tray are restricted to industrial establishments and must be 1/0 or larger so given that randii meets neither criteria he is pretty much stuck using conduit?

Most of my experience is with ITC, PLTC and Teck cable in an industrial environment, my garage subpanel has 6 gauge Teck ran pretty much like randii in the rafters and passed inspection.

[Oxjockey]

My inspector black-flagged my home-built wood runners but gave me props for not just threading the conductors through the rafters (his term 'nailbait' was kinda funny).

He suggested i use an 'approved raceway' but I'm having some issues finding affordable product for spanning ~50' of unfinished attic/rafters between my main panel and sub-panel.

Randii


:confused:

This is over your attic? What am I missing? Why go with a raceway at all, expecially if it's Romex?

I just ran my 6/3 through 50' worth of wall studs or floor joists. (like the rest of the wiring in the house)

[Gummi Bear]

The tray/gutter I am thinking about looks like the attached picture and is not very expensive. Due to my location my familiarity with the NEC is not as good as you who have to abide by it.

So allow me some questions to satisfy my curiosity??

(392.6) Cable tray covers are required to provide protection for cables only where cable trays are subject to mechanical damage?

(392.3) Would THHN be allowed to be used in a tray installation?

(392.10) States that single conductor cables in tray are restricted to industrial establishments and must be 1/0 or larger so given that randii meets neither criteria he is pretty much stuck using conduit?

Most of my experience is with ITC, PLTC and Teck cable in an industrial environment, my garage subpanel has 6 gauge Teck ran pretty much like randii in the rafters and passed inspection.

OK, I see the stuff that you're talking about. :cool: That's cable tray, the stuff that I was talking about is unistrut, you can snap a cover on to and it becomes a wireway of sorts for branch conductors. I've installed stuff like that on extremely long runs of lighting along conveyor systems ASRS racking and stuff like that. What you posted looks to me like a small cable tray. If your cable is not a 'tray cable' it must be in a raceway. I've never installed THHN smaller than 500 kcmil in a tray, and honestly, I've never looked into the exceptions any deeper than that. I'll grab my code book on Monday morning and check that out. Thanks. (my masters prep starts this Monday night, I'm getting excited) So you're a control specialist, is that right? The little bit that I've done, I sure enjoy. It is a whole new and different way of thinking of installation and sequence of events. I'd like to learn the programming end of it all at some point too.

Ox,
He's using individual conductors, and that's why he needs a raceway. Romex is indeed considered a raceway, when in an attic or wall and strapped or supported properly, but not exposed on the surface of a wall. Honestly, I think that residential work is a bigger pain in the butt than commercial or industrial at times. All of the exceptions, FPN's and other such silliness is mind-numbing at times.

[jasonmt]

Gummi Bear: Now I see we were talking about different things (Unistrut vs. Tray). I am working on my instrumentation ticket now but I have a few tickets that are more mechanical related. Trying to bridge the gap between mechanical and electrical/instrumentation as most people have one or the other but not both.

[tippy99888]

I may be dreaming, but I was hoping for an 'open' raceway, not conduit... because I don't want to downrate the conductors (though IIRC, I had ampacity tolerance to to so) and I don't want to pull the connectors (because I am LAZY).

Lazy old me is hoping for easy-to-assemble tray-style raceways that I could just lay the existing conductors into without disconnecting. Oh, and since I'm dreaming, it needs to be cheap and come with self-installation gnomes. :rolleyes:

Randii (prolly just gonna have to pull it in big conduit)


Hate to be the bearer of bad news, but in my code book, I have 2 tables to size the wire from, Table 1 says "Allowable ampacities for single copper conductors in free air" and table 2 says "Allowable ampacities for not more than 3 copper conductors in raceway or cable" there are other tables that go along with these but I thought you might want to know that you'll still have to "downrate". :D There are lots of other factors, but for this install, I don't think there relivant.

[bigun]

Since you are running no more than 50 feet and have no more than 2 "load carring conductors" I wouldn't worry about derating when running it in conduit. As has been said before run it in PVC 1 inch minumum But to make it easy I would run it in a bigger size oplus if for some reason You ever decided to up grade larger conduit would be needed. I run 1/2, 3/4,1 inch then jump straight to 2 inch I figure if it needs to be bigger I am going to make sure if I ever have to pull it out it's going to be easy for me!!!

[SHERPA]

please correct me if needed, but to my best knowledge you cannot run romex
of any legth in conduit. period. doing so is not to code, and would require
tearing it all out. if you wanted to run thhn, then run it in conduit,,, if half
the building is in romex though, at some point you would have to have a terminal block to change from thhn to romex... would that be to code-?

--confused........... Sherpa

[Oxjockey]

please correct me if needed, but to my best knowledge you cannot run romex
of any legth in conduit. period. doing so is not to code, and would require
tearing it all out. if you wanted to run thhn, then run it in conduit,,, if half
the building is in romex though, at some point you would have to have a terminal block to change from thhn to romex... would that be to code-?

--confused........... Sherpa

AFAIK, you can run it for a drop. Mine is 3' or less.

[Hanr3]

All this talk of single conductors running open in the attic reminds me of Knob and Tube wiring from the turn of the century. You can still find the stuff in older homes. It's a pain in the butt to work on. Once you touch it, you have to bring it to code. New runs, and the whole circuit has to be terminated or removed.

Save yourself a headache. Use one of the wires as a pull line and run romex cable. It will be much faster, cheaper and a whole lot less of a headache in the long run.

[Poley]

Fuck it go the CHICKEN SHIT WAY, and get it inspected then do it your way...

Then when it burns down, tell the insurance company it was inspected so it is not your fault...


Or offer the guy a C-Note,and it will pass next time....


it's up to U!!! Get'UR DONE!!! :flipoff2: :evil: