Sizing the LB

[RUWired]

I'm finishing a conduit run from another contractor and the work has three problems already.The wire is the wrong size for the breaker, the ground wire is to small for the breaker and the lb is to small for the amount of wires listed inside the housing.I'm looking for the article that states the number of conductors inside the LB has to be followed.I thought 314 for going out the back the condulet had to be 6 times the diameter.
Rick

 

[Dennis Alwon]

I'm finishing a conduit run from another contractor and the work has three problems already.The wire is the wrong size for the breaker, the ground wire is to small for the breaker and the lb is to small for the amount of wires listed inside the housing.I'm looking for the article that states the number of conductors inside the LB has to be followed.I thought 314 for going out the back the condulet had to be 6 times the diameter.
Rick

Many LB's will tell you the maximum size conductors but for pull you must use 314.28

 

[sybrandy]

Yes most LB fittings are stamped inside the LB itself with the size and number of conductors. I believe these are sized for THHN but I am not sure. I use Rigid LBs a lot and usually, if the conduit being used is sized according to the 40 percent fill, you will be alright

 

[chris kennedy]

Heres a possible out for you.

314.71 Size of Pull and Junction Boxes.

Exception No. 1: Where a conductor or cable entry is in the wall of a box opposite a removable cover, the distance from that wall to the cover shall be permitted to be not less than the bending radius for the conductors as provided in 300.34.

 

[augie47]

here is a link to CrouseHinds Form 5 LB conductr fill which will give you some idea.
http://www.crouse-hinds.com/crousehinds/newproducts/relatedinfo/Form5%20Final%20Dec%202005.pdf

 

[RUWired]

The LB 400M is rated for (3) 500 xhhw conductotrs and there are 4 and a # 2 awg ground already installed.One of the LB covers was actually bent because one of the conductors was'nt pulled completely through.

So with 314.28(A)2 exception, use table 312.6(A) and follow 6 times the conduit size.

 

[stickboy1375]

Should help.

View attachment 1540

 

[RUWired]

Should help.

Yes that helps.So if the maximum conductors are exceeded for what the LB is rated for, then thats a listing violation.

 

[stickboy1375]

Yes that helps.So if the maximum conductors are exceeded for what the LB is rated for, then thats a listing violation.

I would say so...

 

[RUWired]

Thanks all for your help.This run is a 4 x parallel run that will probably not pass an inspection and need to be fixed up as an extra i hope.

Rick

 

[Cow]

Pulling 4-500's back out of an already too small LB four times over does not sound like fun at all...:roll:

 

[RUWired]

Pulling 4-500's back out of an already too small LB four times over does not sound like fun at all...:roll:

And then reload it with 600 kcmil's.The run is 400' +-.