LFNC inserted into RNC

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buck33k

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Washington state and North Carolina
I saw the following installation recently and am wondering what violations, if any, would pertain.

2" RNC emerges from a concrete slab up into the bottom of an electrical cabinet. It is capped with a bell end.
Inserted into this 2" RNC is a short piece of 3/4 LFNC with connector and bushing.
The LFNC is terminated to a piece of equipment. Conductors are (3) #12 THHN/THWN. Included is an equipment grounding conductor.
 
Your first post says...
2" RNC emerges from a concrete slab up into the bottom of an electrical cabinet. It is capped with a bell end.
Click to expand...
Assuming this is an "open-bottom" electrical cabinet setting directly on the slab, that is all that is required... but in what way, or for what purpose is the other end of the LFNC "terminated to a piece of equipment"? Is there another enclosure within the electrical cabinet? If so what is its purpose?

Sounds like the LFNC is unnecessary, but was installed simply as a means of physical protection. As such, I don't believe there to be any violation... but I wouldn't have put the connector or bushing on the end in the 2" RNC.
 
Maybe a little better explanation of the installation.
The RNC is installed in the concrete...is it a sleeve? Where does it start from?
When you say it ends up in the bottom of an electrical cabinet, does that mean it is terminated in the open bottom of a switchboard/gear or it is in the bottom of a cabinet mounted to the wall?

"The LFNC is terminated to a piece of equipment" - what piece of equipment?
 
photos

photos

These photos show a near identical piece of equipment for illustration purposes. This is service equipment for DSL. 100 amp main on left and 30 amp generator breaker on right with load center below. The service lateral enters from below up the left side in conduit to a meter above (meter not shown). About 8" or 9" above the slab is a metal barrier with KO's. This is the area I have questions about.

I saw LFNC terminated in this metal barrier and inserted into the 2" PVC with bell end for branch circuits. What are the violations here if any?

New question: Could'nt the branch circuits pass through the bell end and through a chase nipple in the metal barrier? Why connect the conduit?

I hope these photos make it clear.

Edit: Does'nt look like my photos made it!

Edit: To my dissapointment, my photos exceed the 39 kb limit. I will be working on fixing this problem.
 
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One more try at submitting the images. Hope this works.

IM002919-1.jpg

IM002924.jpg
 
Is there a plate goes over the front of that bottom section, below the door? Or is it open like that all the time? (not the door, the area between the slab and the bottom of the controls section enclosure).
 
buck33k said:
Yes, there is a plate which covers the lowest section down to the ground. Nothing would be exposed.
Click to expand...
Then I see no special issue. No different than switchgear. Pass the conductors through the metal barrier with whatever sort of bushing works. Just my opinion, though. I don't see anything out of the ordinary in your pics now that you say it's all closed up at the bottom normally. I just wonder what the manufacturer of that particular cabinet intends (not the OEM who fitted it out, the actual cabinet maker).
 
Buck33k,

I think you might be changing the rating of the cabinet ( gasketed ) by

leaving an open hole in the bottom. IMO the raceway should go all the way.
 
Buck,

You were talking about using a chase nipple, that is the hole I was refering

to. As far as the 3/4" LFNC , I think that it keeps the rating of the cabinet

but still feel that conduit should be run as a complete system. Violation or

not a violation, guess that's the IE's call.
 
It almost looks like the 2" RNC is installed as a duct, and the 3/4" LFNC is pulled through the duct. Where do the ends of the LFNC go and to what do they get attached?

If "wet rated" conductors are run in the LFNC from one termination to the other, then it doesn't seem to be a problem.
 
Bob NH - In the case of the LFNC first metioned, it only went into the 2" RNC about a foot and connected to the floor of the cabinet.

After considering the other comments, I'm now thinking that any conduit systems emerging up into the bottom of the cabinet should be terminated to the metal floor.
 
benaround said:
Buck33k,

I think you might be changing the rating of the cabinet ( gasketed ) by

leaving an open hole in the bottom. IMO the raceway should go all the way.
Click to expand...
I too agree with these comments. The space referred to where the RNC is located most likely is not listed for bare conductors (note that there is no bottom in this space). I have done similar installations for BellSouth and they require wires to be enclosed in this space.
Why not knock out a hole directly above the RNC and extend it to the cabinet?
 
New question: Could'nt the branch circuits pass through the bell end and through a chase nipple in the metal barrier? Why connect the conduit?



Good question. If its all enclosed inside a listed piece of equipment I would just protect the conductors where the pass through the plate and eliminate the LFMC.


I am also confused. It sounds like the branch circuits are run in the same conduit as the service lateral. Which is most likely unfused?


My appologies if I misunderstood you post.
 
bstoin said:
Why not knock out a hole directly above the RNC and extend it to the cabinet?
Click to expand...

I think what prompted the use of the LFNC was that the KOs did'nt line up to the RNC emerging from the concrete. The LFNC angled to a smaller KO off to the side. It was inserted into the 2" RNC without reducing fittings. I think an inspector might find fault with this but I'm not sure of the exact violation.
 
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