2" LB Fill Question

[c2500]

I know you can place 4 4/0 wires in a 2" Schedule 40 PVC Conduit. I opened the cover of an LB I had purchased and it says on an added label "maximum of 3 4/0's". It was a brand from the supply house, Royal I think. Is there a direct code reference for this as I want to be compliant? Also, is there a brand that allows 3 4/0's and a 2/0? I am running SER from a meter can/main to a sub panel. The conduit is there to protect the SER before it enters the crawl space.

Thanks,

c2500

 

[infinity]

Take a look at 314.28(A)(3). You cannot exceed 3-#4/0 in that conduit body.

 

[augie47]

Your Code reference is 314.28.(A)(3)
The LB is limited to the manufacturer rating or the 6 X requirement.
In metallic LBs there are forms that will allow the (4) 4/0, but I don't know of any non-metallic.

 

[nakulak]

in my limited experience, overfilling LBs (which I have done myself) and using 25% fill xp fittings on 40% filled pipe (which I have almost done myself) are 2 extremely common wiring errors

 

[hillbilly1]

Your Code reference is 314.28.(A)(3)
The LB is limited to the manufacturer rating or the 6 X requirement.
In metallic LBs there are forms that will allow the (4) 4/0, but I don't know of any non-metallic.

I've had inspectors ignore the manufacture rating and will not go with anything less than the 6X requirement.

 

[infinity]

I've had inspectors ignore the manufacture rating and will not go with anything less than the 6X requirement.

Those inspectors should be following the NEC not their own code. :roll:

 

[hillbilly1]

Those inspectors should be following the NEC not their own code. :roll:

And this was not a small town inspector either.

 

[cadpoint]

I don't see how the stamped cubic inch volume can be abridged.

I've also pondered the limit of a Wire Size veries the Cubic Inches involved!

I've seen the one size up used with a reducing threaded bushing... :roll:

 

[c2500]

I passed today by using 2 1/2" PVC with the LB then reduced down to 2" for the male adapter and connector for the SER after the LB. The supply house did not have a 2 1/2" connector so the $12.00 reducer bushing was used.

They burn you when you go to 2 1/2" fittings.

Thanks for the code reference infinity. Also thanks for the other info everyone.

c2500

 

[jeremysterling]

Mogul LB's are a rip-off. Going a size up with RE's is one solution.

I like Chris Kennedy's simple trough design that avoids inspector interpretation:

http://forums.mikeholt.com/showpost.php?p=1034621&postcount=18

post #18

 

[Pierre C Belarge]

Is the equipment ground conductor that is installed with the ungrounded conductors required to be bonded to the enclosure?

 

[danickstr]

I like the 2 1/2" bushed up LB and use it myself for that issue. The wholesale house here tried to ding me for 97 bucks and I complained. They took it down to 66 bucks. I found it at the Orange Box for about 30. Why do they do it to me?

 

[don_resqcapt19]

Mogul LB's are a rip-off. Going a size up with RE's is one solution. ...

One issue with the use of an oversized LB is that if they are over 100 cubic inches they have have to be supported independent from the conduit. 314.23(E). A Red Dot 1.5" mogul LB has a volume of 128 cubic inches. The exception to the section would permit the 1.5" LB to be supported by 1.5" conduit but not by a smaller conduit.

 

[don_resqcapt19]

Is the equipment ground conductor that is installed with the ungrounded conductors required to be bonded to the enclosure?

No. See 250.148.

 

[Cow]

Is the equipment ground conductor that is installed with the ungrounded conductors required to be bonded to the enclosure?

Since the circuit conductors are not spliced, I would say no. 250.148

Generally, we bump the LB up a size or two to help the fill requirements if we're cutting it close.

 

[c2500]

One issue with the use of an oversized LB is that if they are over 100 cubic inches they have have to be supported independent from the conduit. 314.23(E). A Red Dot 1.5" mogul LB has a volume of 128 cubic inches. The exception to the section would permit the 1.5" LB to be supported by 1.5" conduit but not by a smaller conduit.

Don,

If you ran 2 1/2" pvc from the meterbox/main combo into a 2 1/2"LB then out of the back of the LB with 2 1/2" then bushed down to 2" so that a connecter clamp could be used would be legal? That is the way I am reading it.

c2500

 

[don_resqcapt19]

Don,

If you ran 2 1/2" pvc from the meterbox/main combo into a 2 1/2"LB then out of the back of the LB with 2 1/2" then bushed down to 2" so that a connecter clamp could be used would be legal? That is the way I am reading it.

c2500

It looks like the exception would permit that. If you use the 2.5" LB with 2" conduit, then you can't use the conduit to support the LB.

 

[Sharpie]

Why not just run the whole thing in 2-1/2"

 

[Rewire]

Why not just run the whole thing in 2-1/2"

Save a penny or two? We use 2 1/2 all the way it looks better and eliminates putting in reducers

 

[c2500]

Ok fellas,

I have only been able to find 2" connectors that will allow me to clamp down on the SER. The supply house could only find 2 ", nothing larger. Therefore, I have to bush down. The inspectors here want the SER clamped as it leaves the conduit. Is there a 2 1/2" connector that I can use on the SER? I simply have to screw it into a female adapter. It does not have to be weather tight.

Thanks,

c2500