# 20' lengths of conduit.



## Salvatoreg02 (Feb 26, 2011)

Does anyone know if 20' lengths of 4" EMT can be supported greater then 10' by manufactures specifications. Or 10' by code for any given length ?


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## user4818 (Jan 15, 2009)

Are you an electrician? :confused1:


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## Dennis Alwon (May 9, 2009)

Salvatoreg02 said:


> Does anyone know if 20' lengths of 4" EMT can be supported greater then 10' by manufactures specifications. Or 10' by code for any given length ?


I would do it as the code permits however you are probably allowed to use the manufacturers spec. How far will the manufacturer allow?


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## Salvatoreg02 (Feb 26, 2011)

Dennis Alwon said:


> I would do it as the code permits however you are probably allowed to use the manufacturers spec. How far will the manufacturer allow?


That's thing haven't done any research on what they would allow. This came up in conversation during coffee.


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## Salvatoreg02 (Feb 26, 2011)

Peter D said:


> Are you an electrician? :confused1:


It's a question obviously you don't have the answer. Thank you anyway for your support. LOL


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## user4818 (Jan 15, 2009)

Salvatoreg02 said:


> It's a question obviously you don't have the answer. Thank you anyway for your support. LOL


Right. :laughing: 

You should follow the NEC requirement for spacing supports. I don't see how the length of the conduit has any bearing on it.


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## 10492 (Jan 4, 2010)

Peter D said:


> Are you an electrician? :confused1:



I hope so. I don't think he has a future remodeling closets at all.


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## B4T (Feb 10, 2009)

Dnkldorf said:


> I hope so. I don't think he has a future remodeling closets at all.


:laughing::laughing:


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## Amish Electrician (Jan 2, 2010)

There are some things so basic that they're among the first things covered in your training. Later, in your classes, things are covered in a certain order - you know, like basic arithmetic before we get into nuclear physics.

How often to support pipe is one of these 'early' topics. Even if you don't go through a formal union apprenticeship, you learn to support your stuff right after you learn which end of the shovel is the 'dumb' end.

So the question .... can I space my supports farther apart just because the pipe is big and long ..... pretty much screams 'this guy has no business doing electric work.' Whatever his other qualifications are, there are some serious gaps in his training .... like an English teacher who thinks the alphabet has only 18 letters in it.

Code says no more than ten feet apart. That's why, in this CONSTRUCTION trade, we spend so much time making things, and rather little time chasing electrons.


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## Salvatoreg02 (Feb 26, 2011)

Here we go again with wise azz remarks. I understand what the NEC states, but it is quite easy to understand the larger the diameter of a conduit the pipe can be supported more then 10' if the manufacture states the conduit can be supported at intervals greater 10'. 
Thanks I'll call the manufacture.


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## don_resqcapt19 (Jul 18, 2010)

Salvatoreg02 said:


> Here we go again with wise azz remarks. I understand what the NEC states, but it is quite easy to understand the larger the diameter of a conduit the pipe can be supported more then 10' if the manufacture states the conduit can be supported at intervals greater 10'.
> Thanks I'll call the manufacture.


 It doesn't matter what the manufacturer tells you...he can't change the code rule to permit a longer space between supports. 

The code section for EMT is clear that the maximum spacing is 10' and even if the raceway is structurally sound for a spacing of 20', you can't use a 20' spacing without violating the code. 

If it really is suitable for longer spacing then the EMT manufacturers need to submit proposals to change the code.


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## nolabama (Oct 3, 2007)

Salvatoreg02 said:


> Does anyone know if 20' lengths of 4" EMT can be supported greater then 10' by manufactures specifications. Or 10' by code for any given length ?


No. Not even vertical runs.


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## Control Freak (Mar 8, 2008)

Absolutely NOT! Manufacturers make many things but do not enforce the Code.


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## RIVETER (Sep 26, 2009)

Salvatoreg02 said:


> Does anyone know if 20' lengths of 4" EMT can be supported greater then 10' by manufactures specifications. Or 10' by code for any given length ?


I've not heard of 20 foot lengths of electrical conduit.


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## 360max (Jun 10, 2011)

don_resqcapt19 said:


> It doesn't matter what the manufacturer tells you...he can't change the code rule to permit a longer space between supports.
> 
> The code section for EMT is clear that the maximum spacing is 10' and even if the raceway is structurally sound for a spacing of 20', you can't use a 20' spacing without violating the code.
> 
> If it really is suitable for longer spacing then the EMT manufacturers need to submit proposals to change the code.


..in addition to what Don stated (regarding conduit), you have to adhere to the minimum spacing requirements, whether they are in the NEC *or* the manufactures installation instructions, to be code compliant.


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## 360max (Jun 10, 2011)

RIVETER said:


> I've not heard of 20 foot lengths of electrical conduit.


....because for the most part there useless and too much of a pain to deal with.


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## Salvatoreg02 (Feb 26, 2011)

This is how we bend 20' LMAO. This was my idea for the first bend untill we get longer legs made up for the bender


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## Mshea (Jan 17, 2011)

CEC rules are the same except the measurment is in meters but it is 10 feet too. We did change cable tray rules to allow for manufacturer spans but EMT rules are not likely to ever change.


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## Frasbee (Apr 7, 2008)

I believe EMT stays 10'. 

However, rigid pipe, even PVC rigid conduit requirements are increased as the diameter increases.


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## Amish Electrician (Jan 2, 2010)

Frasbee, I don't know your source for that opinion.

My NEC (334.30(B)) says RMC "shall be supported at intervals not exceeding 3m (10-ft.)" I don't see any reference to the size of the pipe, etc.

There is allowance for a longer run for a power drop to a machine, where the vertical pipe can be run as much as 20-ft, without additional support, provided a number of conditions are met. Simply doing this is strictly forbidden:










(Look to the thermostat, hanging from the completely unsupported piece of pipe).


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## don_resqcapt19 (Jul 18, 2010)

Amish Electrician said:


> Frasbee, I don't know your source for that opinion.
> 
> My NEC (334.30(B)) says RMC "shall be supported at intervals not exceeding 3m (10-ft.)" I don't see any reference to the size of the pipe, etc.
> 
> ...


 See 344.30(B)(2) and Table 344.30(B)(2).


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## Chris1971 (Dec 27, 2010)

Peter D said:


> Are you an electrician? :confused1:


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## Salvatoreg02 (Feb 26, 2011)

So, we finally got our measurements correct for bending a 3'7" 45' offset without having to modify our Greenlee bender. We need to make 30 offsets usinng 20' EMT conduits ranging from 4- 2-1/2". 
Post pictures tomorrow


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## BBQ (Nov 16, 2010)

> So the question .... can I space my supports farther apart just because the pipe is big and long ..... pretty much screams 'this guy has no business doing electric work.'


Maybe he knows more than you are giving him credit for.

The support requirements for RNC (PVC) change per the size of the conduit but in no case farther than 10' 


_However ...._

The support requirements for RMC (GRC) change per the size of the conduit and exceed 10'

For example in many instances 3" and larger RMC can be supported 20' apart. See Table 344.30(B)(2) and the supporting text.


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## wildleg (Apr 12, 2009)

BBQ said:


> Maybe he knows more than you are giving him credit for.
> 
> The support requirements for RNC (PVC) change per the size of the conduit but in no case farther than 10'
> 
> ...


All true, but the only pipe the OP mentioned was EMT


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## BBQ (Nov 16, 2010)

wildleg said:


> All true, but the only pipe the OP mentioned was EMT


Yes, very true and I made sure not to leave out that I was talking about other raceways.

The point is that in many cases size does matter. :thumbsup:


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## Amish Electrician (Jan 2, 2010)

Thank you, Don, for the education!

I do not find such a table for EMT; I'm afraid to look at IMC


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## don_resqcapt19 (Jul 18, 2010)

Amish Electrician said:


> Thank you, Don, for the education!
> 
> I do not find such a table for EMT; I'm afraid to look at IMC


The rule for IMC refers you to the table for rigid.


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## Salvatoreg02 (Feb 26, 2011)

Amish Electrician said:


> Thank you, Don, for the education!
> 
> I do not find such a table for EMT; I'm afraid to look at IMC


Let me just state this for the record 10' intervals for support between supports is required for most conduits and within 3' of a coupling. Did you ever think for a second that that's based on 10' sections of conduit. 
My point is as 20' lengths become more demanding eventually EMT will be allowed or possibly even now can be supported an intervals greater then 10'.


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## Salvatoreg02 (Feb 26, 2011)

All of our conduit runs with 45' offsets.


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## don_resqcapt19 (Jul 18, 2010)

Salvatoreg02 said:


> Let me just state this for the record 10' intervals for support between supports is required for most conduits and within 3' of a coupling. Did you ever think for a second that that's based on 10' sections of conduit.
> My point is as 20' lengths become more demanding eventually EMT will be allowed or possibly even now can be supported an intervals greater then 10'.


 There is nothing in the code that requires supports within 3' of conduit couplings. There is nothing in the code now that will let you exceed 10' between supports for EMT, even if you are using 20 sections of conduit. 
If someone submits a proposal and has documentation that says it is safe to support 20' lenghts of EMT a intervals greater than 10', then it would be permitted.


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## Frasbee (Apr 7, 2008)

2008 is hairy about the 3ft rule.

"(3ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination."

It has been argued here that a coupling counts as a either a conduit body (condulet?) or tubing termination. I just think it's odd that they use the word coupling in the NEC elsewhere, but not here.


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## BBQ (Nov 16, 2010)

Frasbee said:


> 2008 is hairy about the 3ft rule.
> 
> "(3ft) of each outlet box, junction box, device box, cabinet, conduit body, or other tubing termination."
> 
> It has been argued here that a coupling counts as a either a conduit body (condulet?) or tubing termination. I just think it's odd that they use the word coupling in the NEC elsewhere, but not here.


The code used to say fitting in place of 'termination' that was changed so that you no longer have to be close to a coupling.

My own method is to keep the supports close to couplings.


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## Frasbee (Apr 7, 2008)

BBQ said:


> The code used to say fitting in place of 'termination' that was changed so that you no longer have to be close to a coupling.
> 
> My own method is to keep the supports close to couplings.


I agree. I think for many here it just makes sense, but without a clear statement to do so, you'll always find runs with 1 strap 5' in and sagging at the coupling.


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## Salvatoreg02 (Feb 26, 2011)

don_resqcapt19 said:


> There is nothing in the code that requires supports within 3' of conduit couplings. There is nothing in the code now that will let you exceed 10' between supports for EMT, even if you are using 20 sections of conduit.
> If someone submits a proposal and has documentation that says it is safe to support 20' lenghts of EMT a intervals greater than 10', then it would be permitted.


So, by saying install as per manufactures instructions and if it was also UL listed wouldn't that be allowed??


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## user4818 (Jan 15, 2009)

Salvatoreg02 said:


> So, by saying install as per manufactures instructions and if it was also UL listed wouldn't that be allowed??


You obviously haven't read a single word in the thread at all. :no:


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## Amish Electrician (Jan 2, 2010)

I think our buddy Sal has been caught, and is trying to wriggle out. With neither physics nor the rulebook on his side, he's trying to finesse things. This whole thread is based on his 'smart comments.'

Just put in the missing supports.

As for 'manufacturers instructions,' I think you'll find that the Steel Tube Institute, in their installation manual, also call for supports on both sides of every change of direction - a matter about which the NEC is silent.

Nor is UL ever going to assert that their listing lets you disregard the NEC.


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## don_resqcapt19 (Jul 18, 2010)

Salvatoreg02 said:


> So, by saying install as per manufactures instructions and if it was also UL listed wouldn't that be allowed??


No. Manufacturer's instructions and UL listings cannot change the code rules to permit less supports. They can require things that are over and above what is required by the code, but they cannot change or override code rules.


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## MaxFuse (Oct 23, 2011)

I think the real determining factor would be the total weight of whatever your going to put in the conduit as far as the distance between supports. The weight will increase with each conduit on the rack, so you would need more and/or beefier supports to handle it.

You definitely want your rack to be able to support the load thats going to be on it.


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## don_resqcapt19 (Jul 18, 2010)

MaxFuse said:


> I think the real determining factor would be the total weight of whatever your going to put in the conduit as far as the distance between supports. The weight will increase with each conduit on the rack, so you would need more and/or beefier supports to handle it.
> 
> You definitely want your rack to be able to support the load thats going to be on it.


While that is all true, the determining factor for the *maximum *distance between supports is the code rule.


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## hardworkingstiff (Jan 22, 2007)

What was Charlie's rule? 

The code doesn't say what you think it says, it doesn't say what you want it to say, it says what it says.

And for EMT, it says securely fastened in place at least every 10 feet.


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## MaxFuse (Oct 23, 2011)

*Charlie's Rule.*_

It doesn’t say what you think it says, nor what you remember it to have said, nor what you were told that it says, and certainly not what you want it to say. And if by chance you are its author, it doesn’t say what you intended it to say. Then what does it say? It says what it says. So if you want to know what it says, stop trying to remember what it says, and don’t ask anyone else. Go back and read it, and pay attention as though you were reading it for the first time_


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