Distance between raceways, conductors damaged?

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xguard

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Baton Rouge, LA
I'm starting off with an assumption here. I have a pull box with two 3 inch conduit entries in top, and a 4 inch conduit entry through the back (side opposite the door opening), with paralleled 350 MCM conductors. My assumption is that the distance from each top entry, where the conductors enter the enclosure to the rear entry where they exit is required to be 6 times the largest trade size raceway which in this case is 4 inch. Please let me know if I'm incorrect and this requirement does not apply here.

My question is, if the conductors were installed and these conduit entries have less than the required spacing, what is typically done? Should these conductors be considered damaged and replaced?
 
Carultch said:
What does this mean for every standard L-body out there, that has #4 and larger wires? Because standard LB's are far from meeting the minimum pull box sizing algorithm.
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You are right and in many cases if you match the conduit body size to the pipe size you will have a violation.
 
Carultch said:
What does this mean for every standard L-body out there, that has #4 and larger wires? Because standard LB's are far from meeting the minimum pull box sizing algorithm.
Click to expand...
Conduit bodies fall under 314.28(A)(3) and are marked with the largest conductors that can be installed. The only issue is that they are only marked for 3 conductors of one size and there is nothing in the code to permit they use of other conductor combinations. This will be addressed in the 2017 code, permitting the use of a volume calculation for this based on the volume of the number and size of conductors that is marked on the conduit body.
 
Carultch said:
What does this mean for every standard L-body out there, that has #4 and larger wires? Because standard LB's are far from meeting the minimum pull box sizing algorithm.
Click to expand...

...most just run larger size LB's with reducers to be code compliant
 
don_resqcapt19 said:
Conduit bodies fall under 314.28(A)(3) and are marked with the largest conductors that can be installed. The only issue is that they are only marked for 3 conductors of one size and there is nothing in the code to permit they use of other conductor combinations. This will be addressed in the 2017 code, permitting the use of a volume calculation for this based on the volume of the number and size of conductors that is marked on the conduit body.
Click to expand...

its about time, lots of MH and ET debates on this issue.
 
jusme123 said:
...most just run larger size LB's with reducers to be code compliant
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But that may result in a violation of 314.23(E). If the trade size of the conduit body is larger than the trade size of the conduit and if the volume of the conduit body exceeds 100 cubic inches, independent support of the conduit body is required.
 
don_resqcapt19 said:
But that may result in a violation of 314.23(E). If the trade size of the conduit body is larger than the trade size of the conduit and if the volume of the conduit body exceeds 100 cubic inches, independent support of the conduit body is required.
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How exactly does one support a conduit body, independent of supporting both conduits within the requisite "distance from termination" for that conduit type?

Conduit bodies don't come with provisions for a mounting fastener, nor have I ever seen a strap that is built to secure a conduit body. The best you could attempt to do is put a strap around the hubs, but there is seldom enough hub length to meet the width of most conduit straps.
 
Carultch said:
How exactly does one support a conduit body, independent of supporting both conduits within the requisite "distance from termination" for that conduit type?

Conduit bodies don't come with provisions for a mounting fastener, nor have I ever seen a strap that is built to secure a conduit body. The best you could attempt to do is put a strap around the hubs, but there is seldom enough hub length to meet the width of most conduit straps.
Click to expand...
I agree that conduit bodies are not designed for independent support, but in my opinion where the conduit body is of a larger trade size than the conduit and where the conduit body has a volume of over 100 cubic inches, the code requires independent support for the conduit body. Depending on the conduit body, you can get to 100 cubic inches with a 3" conduit body. (I have never seen conduit bodies with independent support even where 4" conduit bodies were used with 1 1/2" or 2" conduit)
 
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