SER cable in LB

[flatlander]

Can you strip back the sheathing of SER cable that enters a short piece of conduit and then into a LB. Where the LB is used for protection?
I know you cannot as NM conductors are not labeled THHN or XHHW.

Thanks

 

[Dennis Alwon]

I think 110.3(B) would be the only catch to that.

 

[flatlander]

Ok, what be against listing.
There are MC connectors to EMT I assume that you strip the flex and insert it into the EMT.

I think that is what they are used for.

 

[Dennis Alwon]

The se cable is probably listed as a product with the sheathing on. Do I see a problem stripping the jacket off. No I am just saying that an inspector might say something.

 

[infinity]

If the sheathing is left on you almost certainly cannot get past the 5X minimum bending radius if you use an LB conduit body.

 

[flatlander]

If the sheathing is left on you almost certainly cannot get past the 5X minimum bending radius if you use an LB conduit body.

Hence the reason for the question.

Thanks guys for your replies.

Has anyone here on thus forum ever done this?

 

[iwire]

I think 110.3(B) would be the only catch to that.

How so?

 

[Smart $]

...Has anyone here on thus forum ever done this?

I'm sure someone has.

As long as a large enough LB is used and the sheath is terminated properly*, I don't see any problem.

*An MC connector is not.

 

[goldstar]

Hence the reason for the question.

Thanks guys for your replies.

Has anyone here on thus forum ever done this?

I've done this numerous times and have never had a problem. As Infinity stated you will not be able to make the bend through the LB with the sheathing on. In fact, you'll probably have to unbraid the neutral and twist it like a normal conductor. I've done the following without getting tagged (that's not to say what I did was Code compliant but it was safe) :

• Stripped the sheathing completely off and used the conductors inside a completed run of PVC from the bottom of the meter pan to the main breaker panel
• Used an LB on the bottom of the meter pan and stubbed a length of PVC into a basement, installed a female adapter on the house side of the PVC along with a 2" squeeze connector to hold the SEU cable and then stripped the sheathing off the SEU where it enters the PVC from the basement to the meter pan (this may be more Code compliant than the first method)

I suppose one could argue that once you strip off the sheathing of of the SE cable the conductors are not marked. I haven't seen 4/0 AL that wasn't XHHW but I guess an EI could nit pick.

BTW, I'm just looking back at your OP and noticed that you mentioned it was SER and not SEU. Good luck with that.

 

[Dennis Alwon]

Let me first say that I don't believe this is a safety issue however lets say that we are coming into the top of a panel with ser and it enters the panel thru a 2" pvc sleeve. Can I strip the ser cable? Before you answer this look at 312.5(C)exception(e). Now why would that not also apply to an LB. I am assuming this wire is terminating in some panel thru that LB. Sure we can argue this but as I stated earlier an inspector can , IMO turn it down using this section

312.5(C) Cables. Where cable is used, each cable shall be secured
to the cabinet, cutout box, or meter socket enclosure.


Exception: Cables with entirely nonmetallic sheaths shall
be permitted to enter the top of a surface-mounted enclosure
through one or more nonflexible raceways not less
than 450 mm (18 in.) and not more than 3.0 m (10 ft) in
length, provided all of the following conditions are met:


(a) Each cable is fastened within 300 mm (12 in.),
measured along the sheath, of the outer end of the raceway.

(b) The raceway extends directly above the enclosure
and does not penetrate a structural ceiling.


(c) A fitting is provided on each end of the raceway to
protect the cable(s) from abrasion and the fittings remain
accessible after installation
.
(d) The raceway is sealed or plugged at the outer end
using approved means so as to prevent access to the enclosure
through the raceway.


(e) The cable sheath is continuous through the raceway
and extends into the enclosure beyond the fitting not
less than 6 mm (1⁄4 in.).


(f) The raceway is fastened at its outer end and at
other points in accordance with the applicable article.


(g) Where installed as conduit or tubing, the cable fill
does not exceed the amount that would be permitted for
complete conduit or tubing systems by Table 1 of Chapter 9
of this Code and all applicable notes thereto.

 

[goldstar]

Dennis, I'm having a hard time understanding why if single conductors are installed in a complete PVC raceway they do not have to be secured in place other than by using proper PVC fittings at each end. Yet, if you install "cable" in a raceway it has to be secured in accordance with this section. Can you cite examples of how you would possibly comply with all 7 parts of this section using SE cable ? In my second example I used squeeze connectors where the SE cable entered the cabinet as well as at the stubbed in PVC raceway end. How would I not be compliant ? If you strip off the all the sheathing and use the conductors inside a completed raceway how would that not be compliant ? What am I missing ?

 

[Dennis Alwon]

I am talking about a sleeve. Often people use a piece of 2" pvc and stub up so as to not have to run 15 or so nm cables into the panel with connectors.

#1 is easy to comply with. Just put a staple about 12" from where the cable enters the sleeve.
#2 The raceway cannot penetrate a ceiling that is structural-- a surface mounted panel would work here with a pipe sleeve up to the unfinished ceiling
#3 A bushing or a pvc coupling is installed at the end of the conduit
#4 Duct seal is put in at the end of the sleeve that is not attached to the panel
#5 Cable is not stripped
#6 Strap conduit
#7 Use cable fill if longer than 2'

 

[goldstar]

Now that I understand but how does it relate to using SE cable inside PVC or a PVC sleeve ?

 

[Dennis Alwon]

Now that I understand but how does it relate to using SE cable inside PVC or a PVC sleeve ?

It would be the same. I am not sure I understand your question. Suppose you have an exterior panel and you have to feed a panel inside-- house is a slab- you pipe up out of the panel with pvc and lb into the ceiling of the house and continue the run with ser cable not conduit.

So you sleeving the ser into the panel and continue the run with ser-- does that answer the question

 

[goldstar]

I'm not sure. We may be thinking about two different scenarios so, I'll try to re-explain my installation.

• SEU cable is used out of the top of the meter pan to a service head.
• PVC is used out of the bottom of the meter pan, to an LB and then stubbed into a basement where a main breaker panel is installed in close proximity to the PVC stub.
• Approx. 4' or 5' of the sheathing of the SE cable is stripped off
• A squeeze connector is installed and tightened down on the SE cable
• A PVC female adapter is screwed onto the squeeze connector
• The conduit end of the female adapter is glued and slid onto the PVC stub bringing the stripped end of the SE cable into the LB and eventually into the meter pan
• A squeeze connector is used on the unstripped SE cable end in order to enter the cabinet
• I haven't penetrated any ceilings and the total run is less than 10'

Does that clear things up and make my question understandable ?

 

[Dennis Alwon]

If you want to be technical then your installation- done all over the place, is non compliant. The NEC appears to only allow the sleeve out the top- why I don't know except perhaps it is in relation to indoor panels being stubbed into the crawl space being a fire issue---

Again I see no issue but this section wants the jacket on into the enclosure. I know this is done with mc cable with a proper fitting but one could argue whether the cable is firmly attached to the cabinet.... I know BS but I didn't write this section. I think it could use some work.

 

[goldstar]

I guess we'll leave it at that then.

 

[wwhitney]

Here's an odd idea: slit the outer sheath of the SER after it enters the LB/sleeve, but don't remove it. Maybe slit it twice on opposite sides. That should let the conductors inside move individually without being bound up by the sheath, which should address bend radius concerns. But it also lets you run the sheath into the panel.

Practically, this could be a good solution. As to whether it helps with code compliance I'm not going to comment.

Cheers, Wayne

 

[Dennis Alwon]

Seriously Wayne I doubt there are many inspectors who would argue with what Goldstar stated.

 

[wwhitney]

If you want to be technical then your installation- done all over the place, is non compliant.

I guess I'm going to disagree; if I understand goldstar's description, I don't see any technical NEC violation.

The long list of requirements in 312.5(C) Exception only applies if you don't want to comply with 312.5(C) itself, which requires securing each cable to the cabinet. With a sleeve and a zillion NM cables going through it, it would be tricky to secure each cable, hence the exception.

But goldstar described a single SE cable going into the cabinet, and he described securing it to the cabinet. So he has complied with 312.5(C).

Note that unlike 314, there is no requirement in 312 that the sheath extend 1/4" into the cabinet.

Cheers, Wayne