rjwolfe
New member
- Location
- New Jersey
Is it allowable to support electrical raceways from supports of other systems?(Plumbing, Sheet Metal, etc.)If not, where is that addressed in the NEC?
Conduit Support
- Thread starter rjwolfe
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bphgravity
Senior Member
- Location
- Florida
Re: Conduit Support
Usually not. Conduit supports varies to the specific type of conduit or raceway system you are installing. The code does require that raceways not support other equipment or wiring per 300.11(C) of the 2002 NEC. The problem is listing. Other support systems are usually not listed to support electrical equipment. Go to 300.11(A)(B)&(C) for specifics.
Usually not. Conduit supports varies to the specific type of conduit or raceway system you are installing. The code does require that raceways not support other equipment or wiring per 300.11(C) of the 2002 NEC. The problem is listing. Other support systems are usually not listed to support electrical equipment. Go to 300.11(A)(B)&(C) for specifics.
Re: Conduit Support
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Tom
I'm sorry but I really think that requiring that supports not be used to support more than one crafts work is completely bogus. Most all-thread rod is not listed by UL for any purpose at all. A two by four can be used to build a listed assembly but it is not itself listed. The logical extreme of that veiwpoint is that no structural component can support both a pipe and a cable. It is just absurd.
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Tom
- Location
- Massachusetts
Re: Conduit Support
In my area no one has a problem with running raceways on another trades uni-strut racks, I think the problem comes when someone try's to support from the other system itself, like bolting minis back to back and supporting from a another pipe.
In my area no one has a problem with running raceways on another trades uni-strut racks, I think the problem comes when someone try's to support from the other system itself, like bolting minis back to back and supporting from a another pipe.
Re: Conduit Support
Remember that pipes carrying liquid, will vibrate and move from pressure changes. Steam lines will expand and contract.
I have seen EMT come apart when installed on a plumbing rack.
Most industrial specs will have separation and isolation requirements for electrical conduit racks.
Remember that pipes carrying liquid, will vibrate and move from pressure changes. Steam lines will expand and contract.
I have seen EMT come apart when installed on a plumbing rack.
Most industrial specs will have separation and isolation requirements for electrical conduit racks.
luke warmwater
Senior Member
Re: Conduit Support
I've seen a 3" EMT run supported by a 4" EMT run with back-to-back minnies.(about 175 ft.) It Fell 28ft. straight down. In a printing co. in State College, PA. During the day with a full printing crew working there. How noone got injured or killed is a mystery. There Has to be Some common sense applied.
I've seen a 3" EMT run supported by a 4" EMT run with back-to-back minnies.(about 175 ft.) It Fell 28ft. straight down. In a printing co. in State College, PA. During the day with a full printing crew working there. How noone got injured or killed is a mystery. There Has to be Some common sense applied.
Len_B
Member
- Location
- New Hampshire
Re: Conduit Support
lukeww,
Were there other contributing reasons than just using back to back mini's that the 3" emt came down? Did the 4" emt and support hardware come down with it? I'm not condoning the practice of installing conduit in this fashion, but I've seen it done---and seen it remain intact too many times to count. I'm always amazed at how difficult it can sometimes be to remove old conduit, even when the support system looks cheesy.
Len
lukeww,
Were there other contributing reasons than just using back to back mini's that the 3" emt came down? Did the 4" emt and support hardware come down with it? I'm not condoning the practice of installing conduit in this fashion, but I've seen it done---and seen it remain intact too many times to count. I'm always amazed at how difficult it can sometimes be to remove old conduit, even when the support system looks cheesy.
Len
Re: Conduit Support
With most jobs out here in California we have to do a lot of seismic bracing. How you do it is determined by things like the width of the strut, length of the rods, and also the number & weight of the conduit. When sharing with other trades, someone is going to have to be responsible for these calcs and the bracing. This could cause problems between the crafts if not worked out ahead of time.
With most jobs out here in California we have to do a lot of seismic bracing. How you do it is determined by things like the width of the strut, length of the rods, and also the number & weight of the conduit. When sharing with other trades, someone is going to have to be responsible for these calcs and the bracing. This could cause problems between the crafts if not worked out ahead of time.
Re: Conduit Support
Like Tom said, I think article 300.11 (B)(1) covers using conduit and non approved straps for this purpose.
Bennie, on one job the mechanical contractor marked steam lines with soap stone at the hangers, (rollers) they actually moved 7".( 3.5" in either direction)
Roger
[ March 09, 2003, 11:46 AM: Message edited by: roger ]
Like Tom said, I think article 300.11 (B)(1) covers using conduit and non approved straps for this purpose.
Bennie, on one job the mechanical contractor marked steam lines with soap stone at the hangers, (rollers) they actually moved 7".( 3.5" in either direction)
Roger
[ March 09, 2003, 11:46 AM: Message edited by: roger ]
luke warmwater
Senior Member
Re: Conduit Support
Len_B, the 4" came down also. From what I remember, the 4" was secured properly, but the supports couldn't handle both. I've seen this done before also where it holds, but it's usually with smaller pipe where the wires are also smaller and not as heavy.
That's where I think common sense should also be applied.
Len_B, the 4" came down also. From what I remember, the 4" was secured properly, but the supports couldn't handle both. I've seen this done before also where it holds, but it's usually with smaller pipe where the wires are also smaller and not as heavy.
That's where I think common sense should also be applied.
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