klundy
New member
- Location
- South Carolina
What is the maximum amount of turns that one can pull cable in conduit? And, is it against code to use pvc condulets as a pull point underground?
Underground cable installation
- Thread starter klundy
- Start date
- Status
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Underground cable installation
360 degrees is the maximum, however, 270 is often more practical. it depends on what you are pulling. Keep in mind with PVC if the pulling tension is too high, you will burn through the elbows.
It would be difficult to use a condulet and maintain the required burial depth for PVC conduit.
360 degrees is the maximum, however, 270 is often more practical. it depends on what you are pulling. Keep in mind with PVC if the pulling tension is too high, you will burn through the elbows.
It would be difficult to use a condulet and maintain the required burial depth for PVC conduit.
hbendillo
Senior Member
- Location
- South carolina
Re: Underground cable installation
Another thing to consider is the length of the conduit run. In a very long run it may advisable to limit the turns to 180 degrees or two 90's. As for the condulet underground, the conditions that would allow you to use one underground are very limited. In other words in most conditions it is against code. I would never use a condulet underground. If you had to access it later it would be difficult to find it unless it was very well marked with a permanent type marker. Depending on how deep you are buried it would be a poor pull point.
Another thing to consider is the length of the conduit run. In a very long run it may advisable to limit the turns to 180 degrees or two 90's. As for the condulet underground, the conditions that would allow you to use one underground are very limited. In other words in most conditions it is against code. I would never use a condulet underground. If you had to access it later it would be difficult to find it unless it was very well marked with a permanent type marker. Depending on how deep you are buried it would be a poor pull point.
Re: Underground cable installation
Thanks
This, perhaps is a newbie question but, an engineer and I are having a "discussion" on maximum amount of degrees of bend in any one conduit run. Could you tell me which article deals with this issue? It's been my understanding for years that 360? is the maximum, even though ill advised it is to construct such a conduit run.
Thanks
- Location
- Illinois
- Occupation
- retired electrician
Re: Underground cable installation
ej,
See the xxx.26 section in each of the raceway articles.
Don
ej,
See the xxx.26 section in each of the raceway articles.
Don
- Location
- Massachusetts
Re: Underground cable installation
but code requires a pull point every 360 degrees of bend this can be any combination of degrees.
As Don pointed out look at the xxx.26 section in any of the raceway articles.
You can pull through as many "turns" as you want,
but code requires a pull point every 360 degrees of bend this can be any combination of degrees.As Don pointed out look at the xxx.26 section in any of the raceway articles.
Re: Underground cable installation
Thank you so much for clearing that up in my mind anyway. I don't think this particular engineer will be any different than the proverbial horse that can be lead to water but not made to drink.
Do any of you know of any exceptions to this maximum number of bends in one run rule. It appears consistent through all articles I've went through. I'm suprised with so many occurrences of this that the engineer in question was so certain it was 270?.
Thanks again folks.
Eric
Thank you so much for clearing that up in my mind anyway. I don't think this particular engineer will be any different than the proverbial horse that can be lead to water but not made to drink.
Do any of you know of any exceptions to this maximum number of bends in one run rule. It appears consistent through all articles I've went through. I'm suprised with so many occurrences of this that the engineer in question was so certain it was 270?.
Thanks again folks.
Eric
- Location
- Massachusetts
Re: Underground cable installation
If this is an Electrical Engineer for a project he can specify that you are not to use more than 270 degrees.
But this would have to be in the job specs you bid on, he can't just come in and say no more then 270 degrees in the middle of a project.
If this is an Electrical Engineer for a project he can specify that you are not to use more than 270 degrees.
But this would have to be in the job specs you bid on, he can't just come in and say no more then 270 degrees in the middle of a project.
Re: Underground cable installation
I think the 270? is an internal issue. The problem I have is that she quoted the NEC as being 270? which to my knowledge was inaccurate. I was checking to make sure that a change to this rule was not made while I wasn't looking. I am well aware that the "owner" can increase the requirements "advised" by the NEC. The NEC is only binding if the local authorities decide to adopt it as "code". Personally I would prefer no more than 270? in any one pull. If anyone is ever in the vicinity of New Albany IN and decides to check out that Caesar's Riverboat Casino, they should take a look at the distribution transformers up on 24' platforms and the conduit runs underneath. They were built to the utility company's engineering consultant's specs. Count how many degrees they can see then add another 360 for conduit routing underground. There are no pull boxes or manholes in the run between the boat dock and the southernmost platform. No one needs to tell me it's way beyond NEC guidelines, I already know this. Utility companies routinely disregard NEC rules when it's in their interests.
At any rate I will install the conduit to whatever spec the customer calls for since their crews will be the ones to work on it 20 or more years from now.
Eric
I think the 270? is an internal issue. The problem I have is that she quoted the NEC as being 270? which to my knowledge was inaccurate. I was checking to make sure that a change to this rule was not made while I wasn't looking. I am well aware that the "owner" can increase the requirements "advised" by the NEC. The NEC is only binding if the local authorities decide to adopt it as "code". Personally I would prefer no more than 270? in any one pull. If anyone is ever in the vicinity of New Albany IN and decides to check out that Caesar's Riverboat Casino, they should take a look at the distribution transformers up on 24' platforms and the conduit runs underneath. They were built to the utility company's engineering consultant's specs. Count how many degrees they can see then add another 360 for conduit routing underground. There are no pull boxes or manholes in the run between the boat dock and the southernmost platform. No one needs to tell me it's way beyond NEC guidelines, I already know this. Utility companies routinely disregard NEC rules when it's in their interests.
At any rate I will install the conduit to whatever spec the customer calls for since their crews will be the ones to work on it 20 or more years from now.
Eric
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Underground cable installation
Eric, an Electric Utility is not subject to the NEC, see section 90.2. When pulling a high voltage cable, normally the maximum pullling tension is computed, this is determined by the size raceway, cable, bends, length, etc. They may have good justification for exceeding 360 degrees.
Eric, an Electric Utility is not subject to the NEC, see section 90.2. When pulling a high voltage cable, normally the maximum pullling tension is computed, this is determined by the size raceway, cable, bends, length, etc. They may have good justification for exceeding 360 degrees.
Re: Underground cable installation
Yes, I am painfully aware that utility companies are not subject to NEC guidelines. It is funny however that quite a bit of REA specs are drawn from NEC parameters. Municipal Utilities as well as non-REA utilities love to quote NEC guidelines when it suits them to do so.
In my considered opinion there is no "good" reason for exceeding 360?. I've pulled in runs that were more than 360 and at best they are difficult, at worst dangerous. There are reasons behind the decision, but, I do not consider them good ones. Even at 360, if the run is long, you risk damage to components.
Doesn't really matter all than much anyway, as we have agreed that utility companies aren't subject to the NEC.
Thanks for the feedback.
Yes, I am painfully aware that utility companies are not subject to NEC guidelines. It is funny however that quite a bit of REA specs are drawn from NEC parameters. Municipal Utilities as well as non-REA utilities love to quote NEC guidelines when it suits them to do so.
In my considered opinion there is no "good" reason for exceeding 360?. I've pulled in runs that were more than 360 and at best they are difficult, at worst dangerous. There are reasons behind the decision, but, I do not consider them good ones. Even at 360, if the run is long, you risk damage to components.
Doesn't really matter all than much anyway, as we have agreed that utility companies aren't subject to the NEC.
Thanks for the feedback.
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