how to "stack" EMT conduit?

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  #1  
Old 11-08-06, 06:53 AM
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how to "stack" EMT conduit?

I plan to add a dedicated refrigerator circuit to the kitchen (house built 1965). I have an unfinished basement so I plan to run EMT conduit attached below the floor joists at right angles to the floor joists. However, available space (laterally/horizontally, that is) for running the conduit is a bit crowded so I would like to hang the new conduit directly below an existing run of EMT conduit.

Question: What sort of hardware would be best suited for this sort of conduit stacking?

Question: Is there any sort of code issue with stacking two runs of conduit like this?

thanks,
Brent
 
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  #2  
Old 11-08-06, 07:41 AM
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There are 3 or 4 manufacturers of hardware that have conduit to conduit vertical run fasteners. Here is one product that will do as you want.....(cut and paste)
http://www.erico.com/products/CADDYcfcConduittoConduit.asp

No... there are no code issues

Roger
 
  #3  
Old 11-08-06, 08:13 AM
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Roger, that's illegal to use in this case. NEC requires EMT & conduit not be used to support anything, including other conduit. The fine print on that site even says so much, and suggests scrap conduit be used.

Better to just get some sheet metal and put together a proper hanger.

And no, no code issues stacking conduit!
 
  #4  
Old 11-08-06, 09:09 AM
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Just a thought:

If Brent were to attach a 2x2 (perpendicular) to the floor joists every 4 joists or so and let them extend down below the joist as far as needed, could he then use these to strap the conduit to?

Code says “proper spacing” must be maintained between raceways and such. How far apart from each other is “proper”?
 
  #5  
Old 11-08-06, 05:37 PM
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These are commercial conduit clips they are rated for 20 or 30 pounds. In commercial settings these clips are quite common. In many instances vertical stacking is the only "reasonable" method. They of course are used for many other applications. If the existing raceway is fastened at approved intervals inspectors will allow another conduit to be supported by the existing conduits fasteners.
The concern of the code is long spans of conduit where the amount of weight from conduit and wire exceeds the holding capacity of the fasteners securing the existing conduit.

I will concede that the installation would technically require an inspectors approval. Problem is the work being performed is not a permit required project and a residential inspector is not going to spend his time on this type of work.

I'll withdraw the advice.

Roger
 
  #6  
Old 11-08-06, 06:02 PM
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Metal pipe horizontal;every 10' with coupling. if its cut up and coupled every 5',and at each end or joint
Vertical; every 15' and no more than 1 coupling between supports.
376.30 A-B

PVC: horizontil, every 3'. Vertical: 4', unless listed otherwise.
378.30 A-B

Neither can hang on each other.
So I would say, Yes. If hangers are provided then it's fine.

Roger: I agree,(done it) Not right. Not recommended. Threaded rod and unistrut+ hardware, the right way.
 
  #7  
Old 11-08-06, 06:23 PM
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Don't know how many runs you need but if there is room for a sammie to be screwed into the joist and a 1/4 rod dropped from that and a minnie on the end of that, it would be self supporting. A sammie doesn;t take up much room so one could be screwed in anyplace you have about 1/2 inch of open space.

You could also (as lectriclee posted) use a piece of unistrut and a bracket to attach it to the side of the joist with the unistrut hanging down however far you need to mount as many runs of conduit as needed.
 
  #8  
Old 11-08-06, 07:49 PM
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Roger: I agree,(done it) Not right. Not recommended. Threaded rod and unistrut+ hardware, the right way.


I think some posters from lack of working in the field very long fail to realize that all is not a perfect world out there. We always install with intent to comply with code, but as we all know there are situations that occur that require a compromise with some code articles. These need approval.... one of the biggest reasons we have inspectors. In many cases your modification method is given to you by the inspector and not one of your choice. At any rate my advice was based on having done this exact type installation in a commercial/industrial setting.... only existing conduit support fastners were increased in number. I would venture to say in a residential setting if he had the existing conduit run fastened every other joist an inspector would have absolutely no problem with it. Of course I'm going by what the poster described... that he has no horizontal or lateral space. Otherwise what nap suggested by using a sammie is very resourceful.

Roger
 
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Old 11-08-06, 08:28 PM
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Valid point.

Thats why they'r called "The Authority having jurisdiction".

In a residential setting, I doubt very much you could realize the fears the code has intended to avoid.
 
  #10  
Old 11-09-06, 03:55 AM
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Honestly, if it's rated to 20-30lbs, I don't see anything wrong with using a clip like that in his application- hell, duct tape would probably provide a permanant enough solution to last the life of the house! But I don't want him to go out of his way to get a specialty clip and fail the inspection because of it.

NEC 358.30 doesn't require any particular type of support. He could use any plastic or metal strap nailed to a joist that would be considered "securely fastened" by an AHJ, or even a combination using those clips and additional straps. If the electrical supplier doesn't have suitable hangers, I'd probably pick up a couple hurricane straps and bend them to suit. Really, it couldn't hurt to just put the clips up and see if it passes or fails

FYI Brent- whatever hanger you decide to use, fasten the EMT within 3' of the boxes (or termination points), and every 10' within the run.
 

Last edited by grover; 11-09-06 at 04:09 AM.
  #11  
Old 11-09-06, 05:53 AM
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Thanks for the input, everyone.

I hadn't considered hanging the new conduit from the existing conduit--but it sounds like I should avoid doing that anyway.

The suggestion to use vertical sections of 2x2s attached to the joists won't work here because there is not enough clearance in the available path--which is confined by two parallel runs of HVAC duct.

I wasn't familiar with unistrut but I found their online catalog. Looks like pretty versatile stuff but it's not clear to me which pieces would work best for me. And I'm guessing it might be hard to buy just a few pieces for my application--maybe Graybar?

I haven't heard of "sammie"s and "minnie"s before. From the description, it sounds like this might work well--since it sounds like it involves suspension by some sort of rod. But I'm not sure what I'd be looking for.

Brent
 
  #12  
Old 11-09-06, 07:44 AM
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Why is it that so many people think that running a branch circuit to a refrigerator requires inspection?

If permits were required for this type work you'd have more inspectors than electricians. I doubt if they would even come and inspect it if you asked. They might tell you to have a local electrical service do the work. But they don't come out and inspect the installation of one branch circuit to a refrigerator. They inspect permit required installations like kitchen remodels, swimming pools, hot tubs, room additions, service upgrades....projects that require permits.

The only inspection Brent could get would be to pay an electrician to check it out for him.

Roger
 
  #13  
Old 11-09-06, 07:51 AM
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Roger,

Where I live, and where many people live, the installation of a new branch circuit does indeed require a permit and an inspection. Would most homeowners and most electricians do this? No. Most would do the job and not have it inspected.

Where I am, the inspection is done by a third party, not the government. You pay a separate fee to the third party for the inspection, which they collect when services are rendered. So yes, they will do the inspection.
 
  #14  
Old 11-09-06, 08:10 AM
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I see Bob. My apologies.. I didnt realize this would be the case. In my area the city wouldnt even consider wasting an inspectors time with this. The homeowner just assumes the liabiltiy of having it done right or have it done by a qualified individual. Most of the time homeowners here just call a handyman co. to perform this kind of work if they dont do it themselves. I am quite aware that all lot of electrical is performed by unqualified individuals that dont pull required permits. In my state you do not have to be a licensed electrician to do electrical work...you only have to be under supervision of a licensed contractor. I guess all areas are different in many respects.

Roger
 
  #15  
Old 11-09-06, 03:46 PM
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Originally Posted by Brent0000
I haven't heard of "sammie"s and "minnie"s before. From the description, it sounds like this might work well--since it sounds like it involves suspension by some sort of rod. But I'm not sure what I'd be looking for.

Brent
this is a minnnie. you can put 1/4 inch rod through the hole with a couple of nuts to hold and lock it on.

http://www.minerallac.com/Hangers.htm

actually having a hard time finding sammies online. The type you would need a basically a large wood screw end that has a recieving cup threaded for 1/4-20 all thread to fit in. You screw the wood screw end into the wood and then screw the all thread into the sammie. then you would put the minnie on the all thread and hang your conduit.

I'l keep poking around. Maybe I can find a website for them.
======================

gee. maybe if I spelled it right i would have found them. here is the website. They also have neat ones I havent seen befor. the sidewinder series where you would run the thing in horizontally and then hang a rod from that.

http://www.sammysuperscrew.com/products.htm
 
  #16  
Old 11-09-06, 08:09 PM
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Originally Posted by Roger
Why is it that so many people think that running a branch circuit to a refrigerator requires inspection?
Because it IS required to have a permit and inspection!

Not that you'd ever get caught if you didn't
 
  #17  
Old 11-09-06, 09:15 PM
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Originally Posted by Roger
I see Bob. My apologies.. I didnt realize this would be the case. In my area the city wouldnt even consider wasting an inspectors time with this. The homeowner just assumes the liabiltiy of having it done right or have it done by a qualified individual. Most of the time homeowners here just call a handyman co. to perform this kind of work if they dont do it themselves. I am quite aware that all lot of electrical is performed by unqualified individuals that dont pull required permits. In my state you do not have to be a licensed electrician to do electrical work...you only have to be undhomeowners here just call a handyman co. to perform this kind of work if they dont do it er supervision of a licensed contractor. I guess all areas are different in many respects.

Roger

*wasting an inspectors time with this#

This is revenue ($) and insures it's correct.

*The homeowner just assumes the liabiltiy *

Unless something goes wrong. Then who has the problem?

*homeowners here just call a handyman co. to perform this kind of work*

Blind faith, Bad decision.

*homeowners here just call a handyman co. to perform this kind of work *

I know alot of stuff too. And my limitations. A buck for the Bar, or a job done right? Your choice.

Always remember that people are affected by this work.

If the window isn't right, you wake up cold. If wireing is wrong, you could wake up dead. Don't know, but I think that would S--K.
 
  #18  
Old 11-10-06, 10:37 AM
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Because it IS required to have a permit and inspection!

I think if you spend a little time on the internet or talk to your local electricians in order to get a little broader base of information you will have to decapitalize the "IS" in that statement.....thats sorta like using the word "never".

I really dont want to start an argument here, only trying to address the reality of the trade. I have a tendancy to question those that seem to think all is perfect in the world and the electrical codes are followed to the letter and no compromises and everybody is under the same requirements throughout this country.

I am also not saying you cant do better than code or to not get inspections.

I also dont approve of the use of duct tape though on the RED GREEN Show they do some pretty incredible things with the stuff.

I did discover and learn something today searching different cities code departments on the internet....great tool BTW. And that is that all the large cities I looked at do indeed require permits for additions of branch circuits. I even found one that would allow you to NOT have a permit if you changed out a circuit breaker.....but if you changed the location of the circuit breaker you needed a permit...interesting...I suspect they are worried about the unawareness of a multiwire on that leg.

Now whether you are able to bring yourselves to believe it or not there are many outlying communities in the rural areas of this country that do not require permits for branch circuit additions in existing single family dwellings. New contruction is a different story. Existing agricultural use buildings are then again another story.

I would like to ask a question since I am apparently not intune to the big city codes and regulations.

If your a service electrician and take a call to install a branch circuit for a refrigerator for a home owner. How do you handle that?...since a permit is required?

In my area we go install the branch circuit. Then move on to the next call... much like the plumbers and HVAC techs. But if a permit is required you can not perform any work until the effective date of the permit...its not a wait here while I get the permit for you deal generally its a couple days minimum before the permit is issued.

Roger
 
  #19  
Old 11-10-06, 10:54 AM
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Roger, first off, it's refreshing to have qualified electricians around here that give people real-world advice; I see far too many (well, myself included in this thread, I guess!) yell at people for doing something "illegal" even though it's perfectly safe. For instance, tapping a garbage disposal off a kitchen GFCI string- yeah, it's illegal, but perfectly safe if done right.

But to tell someone that a permit and inspection for branch circuit is not required is a bit disingenuous. I, for one, like to make it clear to people that what they're doing is illegal, but then tell them how to safely do it anyway. I know we've both seen photographs of improperly mounted conduit pulled off of ceilings; without knowing how the existing conduit is mounted, I'd hesitate to suggest someone else tie off it.

For DIYs, I HIGHLY recommend a permit and inspection, because the inspector will ensure it's done legally and safe- the DIY can very easily do extremely unsafe things and not even realize it. But with the caveot that this if they don't get it inspected, they'll probably never get caught. I don't exactly pull a permit for every little project, either At least professionals know how to do it right (or at least are supposed to), which takes much of the safety risk out of it.

And, unless the authority has specifically written code to negate this, International Residential Code 2003 E3303.2 explicitely states that all new electrical work and parts of existing systems affected by new work or alteratiosn shall be inspected by the building official to ensure comliance with the requirements of Chapters 33 through 42.
 
  #20  
Old 11-10-06, 12:53 PM
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Grover I understand your comments. I asked a question to all of you why so many people believe that an inspection is always required for the type work Brent was doing. It was my belief that he probably didnt need one. I have since discovered that I may have errored in that understanding. Though we dont know whether he did or not. If an inspection is required or not Brent should probably do as Bob said his city does and hire a third party. At any rate DIY should get their work inspected if possible or at least someone qualified in the trade should look at it.
I never intended to imply that he did not need an inspection so just do whatever...I simply gave him a solution that I felt would pass an inspection under his particular cicumstances. I have withdrawn that advice. But I would sure like to bet you a cold one that it would be fine with the inspector if that was the only "reasonable" route for an additional conduit run.
I suspected that he was running between HVAC ducts which added to the reason I told him to use that particular caddy clip.
But in hindsight I should have just let it go and stuck with the verbatum of code..no exceptions. Afterall I cant see what he has there and I dont know what his inspectors will allow. Sometimes I just say ..Oh yeah... we have had to deal with that and this is what we are allowed to do.
At anyrate I think I caused this thread to go way off track as the poster has decided to try some other approach. So I'll make no more replies to this thread.

Roger
 

Last edited by Roger; 11-10-06 at 01:10 PM.
  #21  
Old 11-10-06, 01:48 PM
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Back to the OP question.

NO it is not ok to hang anything off of electrical conduit. Hanging more conduit is not allowed. You can tywrap low voltage wire (like a thermostat) only if the electrical conduit and low voltage wire serve the same unit.

To reccomend otherwise is to suggest that people do illegal, substandard work.

I know some members here want to seperate Illegal from Sub Standard, but They Are One In the Same.

If you want to risk a fire at your own house, that is one thing, but to reccomend it to others is another.

Dont bash me with the "how could this part hurt anything" comments. I did not write the code, but I know It was all written with reasons in mind.

A person with several years on a home improvement forum and a couple home improvement projects under his belt, is not more of an authority than the CMP (code making panel) that NFPA (national fire protection agency) hired to update the code.
 
  #22  
Old 11-13-06, 04:50 PM
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Originally Posted by nap
this is a minnnie. you can put 1/4 inch rod through the hole with a couple of nuts to hold and lock it on.

http://www.minerallac.com/Hangers.htm
...
http://www.sammysuperscrew.com/products.htm
==================================================
OK. This is good. I now see how this all should work. Now I know what to look/ask for.

thanks much for the inputs,
Brent
 
  #23  
Old 11-13-06, 06:06 PM
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Originally Posted by grover
For DIYs, I HIGHLY recommend a permit and inspection, because the inspector will ensure it's done legally and safe
Not always the case.

I had an 'inspector' come out from the city after I installed a new outlet; $1.50 chare for inspection...but a $55 minimum charge. Good revenue for the city, on top of the outrageous property tax I pay. But enough of that.

I used a remodel box, had the wire stripped and ready to go. He took one glance and said 'looks fine'. He didn't ask where I tapped in to - could have been old K&T with electrical tape. Didn't crawl up into the attic to see if the spice was correct. Nothing. So I paid $55 for basically a guy to come out and make sure I left enough jacket on the cable.

His inspection insured absolutely nothing. The 'real world' reality is that people will not freely give up more money to the city, and sometimes they do this in lieu of safety. I had my new panel install inspected - obviously a critical part of the electrical system as a whole, and the POCO cannot make the permanent connection at the weatherhead without the approval.

But there is no way I'm going to pay these 'inspectors' $55 every time I put in a new outlet. No way.
 
  #24  
Old 11-13-06, 09:06 PM
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"But there is no way I'm going to pay these 'inspectors' $55 every time I put in a new outlet. No way."




That is very , very true . In my area inspections are just city revenue . Not once have they ever exmained where i got power, the splice, connections , terminations , conduit or anything. walk in look at the box and jacket and say good boy heres your sticker. Some of the times it's just pure blahsphemy.
 
  #25  
Old 11-13-06, 09:56 PM
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yep, I felt like I was getting ripped off. $55 down the drain. House is no safer, but the city is a little richer.
 
  #26  
Old 11-14-06, 02:26 AM
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I've been disappointed in several of my inspections, too, where they only gave a cursory glance.
 
  #27  
Old 11-15-06, 09:24 AM
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"I would like to hang the new conduit directly below an existing run of EMT conduit. "

"Question: What sort of hardware would be best suited for this sort of conduit stacking? "---- If this is 1/2" EMT under 1/2" EMT, then use 4 1/2" EMT straps bolted together in 2 "pairs"
When bolted together, The "upper " pair will grip the existing EMT around it's circumference, and the lower "pair" will grip the new EMT implaced under the exsiting EMT

"Question: Is there any sort of code issue with stacking two runs of conduit like this?"----- If such a support method is a violation, it would be most instructive if the relevant Code article is reffered to.
 
  #28  
Old 11-15-06, 01:58 PM
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300.11(B) says you can't use a raceway to support another raceway unless it's specifically listed for it.

358.12(5) says EMT can only be used to support conduit bodies. It does not permit supporting other raceways from EMT.
 
  #29  
Old 11-15-06, 03:06 PM
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I have to agree with grover's last post.

And I challenge anyone to find a condutit listed for this purpose.

The answer is NO you cannot do this.
 
  #30  
Old 11-15-06, 07:29 PM
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I challenge someone to explain to me why Pattbaa's method is a code violation. It is not using the emt as support but is sharing the same hanger, and using it as its support. This is a very common installation in commercial work. But then I've been delegated to the only done a few home projects cellar for talking out of the box and others comfort zones.

OOOPs I made another reply.

Roger
 
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Old 11-15-06, 07:41 PM
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Originally Posted by grover
300.11(B) says you can't use a raceway to support another raceway unless it's specifically listed for it.

358.12(5) says EMT can only be used to support conduit bodies. It does not permit supporting other raceways from EMT.
.................
 
  #32  
Old 11-15-06, 08:28 PM
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Lectriclee

I respectfully submit that you are misreading the intent of the code in respect to Pattbaas method. He is not supporting that emt from the other emt he is using/sharing the same hanger. this is no different than using flange or plain rod and bat wings for supporting different runs of emt or mc or other from that same rod which is fastened to truss or beam. In perspective the method I suggested at the beginning of this thread is a code violation and I was rightfully corrected by grover.

Roger
 
  #33  
Old 11-16-06, 02:25 AM
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Roger, I had posted those codes in reply to a specific question regarding the legality of hanging from conduit.

>...use 4 1/2" EMT straps bolted together in 2 "pairs"
>When bolted together, The "upper " pair will grip the existing
>EMT around it's circumference, and the lower "pair" will grip
>the new EMT implaced under the exsiting EMT

Perhaps I'm misunderstanding this, but it sounded to me like this was still hanging the lower EMT off the ummer.
 
  #34  
Old 11-16-06, 05:45 AM
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Hmmmm....well I see your point and I am not disagreeing with the code articles that are being used as basis. I'm understanding that he is suggesting that you use the same hanger to support both the emt runs. The difference in this method is that the hanger is listed to support multiple conduit runs and it will have a weight listing. If I am supporting one 3" emt run I must use a hanger that can support it and so forth. If I simply go along an existing raceway and fasten/hang another raceway to that conduit then I am violating code. If I am extending a hanger to support 2 raceways then I am not violating code provided I dont exceed the listing of that hanger. To try to visualize what I'm describing....if I am over a suspended ceiling in a warehouse and I need to get some conduit runs of various raceways such as emt and mc to another area of the warehouse before that ceiling goes in a common method is to use plain rod and bat wings. This is simply unthreaded rod that is secured to the beam or truss. You then clip on bat wing raceway fastners to that rod. You then clip in your raceway, install another bat wing below and clip in another raceway. The rod supports the raceways which are fastened to the rod with the bat wing clips. In contrast if I used this method but just hung the next raceway off the conduit I installed in one bat wing and rod run I would not be code compliant. Total weight remains the same but the rod is no longer the support (common to) both raceways. The bat wing is carrying the weight of both conduits it is only listed to fasten one raceway. The rod can carry the weight but the fastner cannot.

Roger
 

Last edited by Roger; 11-16-06 at 06:44 AM.
  #35  
Old 11-16-06, 08:40 AM
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My appreciation to Grover for citing the relevant articles.

358.12 prohibits using EMT " for the support of luminiares and other equiptments"--- Is EMT under the definition of "equiptments"?

300.11 (B) permits using a raceway as a support for other raceways ( not "equiptments") ---- "under ANY of the following conditions" -- (2), "where the raceway --- supports ( a raceway with control conductors --- my interpertation )"

The point is that 300.11 does not completly exclude a raceway supported from another raceway. Enough "latitude" to permit 1/2 EMT with two #12 conductors to be clamped to an existing 1/2 EMT raceway ?

If an additional raceway is fastened/clamped to an existing raceway exactly at point where the existing raceway is
supported, it's obvious that any stain/tug/pull on the lower raceway in not imposed on the upper raceway.

Also--- if the existing 1/2" EMT is clamped to a U-shaped clamp, "open-end" facing "down", than a 2nd U-shaped clamp, "open end" facing "up", is coupled to the existing clamp, and the two clamps are fastened together. ( does anyone understand this arrangement?)
 
  #36  
Old 11-16-06, 10:36 AM
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I understand exactly what PATTBAA is describing and no, it is not code-compliant.

I once read that the reasoning(?) for this requirement was that if at some future date the "supporting conduit" was abandoned and removed that the "supported conduit" would no longer have the necessary support.

I would think that if an "abandoned conduit" was removed and that abandoned conduit had been supporting another conduit that whoever removed the supporting conduit would then properly support the remaining conduit.
 
  #37  
Old 11-16-06, 02:25 PM
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PATTBAA:

300.11 (B) permits using a raceway as a support for other raceways ( not "equiptments") ---- "under ANY of the following conditions" -- (2), "where the raceway --- supports ( a raceway with control conductors --- my interpertation )"
====================================

your interpretation is incorrect. The section states " where the conduit supports CONDUCTORS OR CABLES".

It says nothing about a raceway. The intent is to allow the ,as example, thermostat wire for a hvac unit. That t-stat wire can be attached to the conduit that carries the power wiring to that unit. This is for wire and cable that is not in a raceway.

The only relevent subsection that would allow one to support conduit from conduit is B(1) but this subsection requires the conduit to be listed for the purpose. If you can get a manufacturer to seek and show such a listing, you can use it. Other than that, it is not acceptabel.
 
  #38  
Old 11-17-06, 08:41 AM
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[QUOTE=nap]PATTBAA:

300.11 (B) permits using a raceway as a support for other raceways ( not "equiptments") ---- "under ANY of the following conditions" -- (2), "where the raceway --- supports ( a raceway with control conductors --- my interpertation )"
====================================

. The section states " where the conduit"------- The word "conduit" does not appear in Art. 300.11 (B), the Art I referred to






"It says nothing about a raceway."-------------

Art 300.11 (B), Raceways used as (a) support --- "RACEWAYS shall be used only as (a) support FOR OTHER RACEWAYS--- under ANY of the following conditions"---- (2), "Where the raceway contains power conductors for electrically controlled equiptment------ "

Interpretations welcome----

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The only relevent subsection that would allow one to support conduit from conduit is B(1) but this subsection requires the con
 
  #39  
Old 11-17-06, 09:43 AM
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Join Date: Mar 2005
Location: Chesapeake, VA
Posts: 340
In its entirety:
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300.11(B) Raceways Used as Means of Support. Raceways shall be used only as a means of support for other raceways, cables, or nonelectric equipment under any of the following conditions:

(1) Where the raceway or means of support is identified for the purpose.

(2) Where the raceway contains power supply conductors for electrically controlled equipment and is used to support Class 2 circuit conductors that are solely for the porpose of connection to the equipment control circuits.

(3) Where the raceway is used to support boxes or conduit bodies in accordance with 314.23 or to support liminaires (fixtures) in accordance with 410.16(F).

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Exception (2) does not allow the raceway to support another raceway. When they talk about a raceway containing conductors, they mean the raceway doing the supporting, and even then only for certain circuits that are electrically controlled- in a typical house, the ONLY circuit that would apply is the furnace. It can ONLY support Class 2 circuit conductors (like thermostat bell wire), and even then only if they were the Class 2 conductors associated with the raceway, like the thermostat. I completely agree with nap on this one.
 
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