pvc terminal adapters with metal lock nut

[mnn1980]

HELLO,im working on a project (v-dot bridge lighting)with a new electrical inspector.He says no metal parts can be inside of a standard 4 inch sq. box,not even metal locknut on ta.making use ground the 3/8 nut supporting boxes as well.Can anyone find a code sitting to help with this elementary problem.pvc pipe, pvc ta,metal lock nut, indoors....please help we are going bananas.

 

[infinity]

Is the box metal or PVC?

Welcome to the forum.

 

[mnn1980]

box is pvc

box is pvc

pvc

 

[mnn1980]

its a 3/4 pvc pipe in and out of a 4 sq. pvc outlet box.We want to use a metal lock nut on the ta.I've installed this way for years no problems..........It's a mile long tunnel with lights and recpts. pvc raceway is installed along concrete wall.

 

[Ponchik]

Did he give you a code section that you have violated??

If the inspector doesn't like the metal in the PVC box, then I guess you can install a female adaptor at the end of the conduit with a PVC chase nipple through the box.

 

[6sunset6]

Carlon makes PVC nuts but 1/2 and 1 only it looks like.
Use a box adapter with a coupling on the outside. I was chasing this exact problem a month ago. The code says , somewhere, that metal in the box is ok if it will not likely be contacted by energized sources.
I just used metal nuts and the inspector never said a word. It is a bummer if it is all piped and the AHJ does not like it.

 

[6sunset6]

I was wrong I guess could not find the ref to metal in the pvc box. Maybe it was in an earlier version.
How about a metal nut with an egc screw in it. Hubbell-Killark ZHLN-270 Expensive though.

 

[infinity]

its a 3/4 pvc pipe in and out of a 4 sq. pvc outlet box.We want to use a metal lock nut on the ta.I've installed this way for years no problems..........It's a mile long tunnel with lights and recpts. pvc raceway is installed along concrete wall.

I'm guessin that this isn't a wet location?

I see no code section that would prohibit the locknut but the 3/8" support nut is a problem. The support is required to be on the outside of the box or have a provision in the box for preventing contact with the mounting screws.

314.43 Nonmetallic Boxes. Provisions for supports or
other mounting means for nonmetallic boxes shall be out-
side of the box, or the box shall be constructed so as to
prevent contact between the conductors in the box and the
supporting screws

 

[edmu]

Steel locknut is listed for use with Rigid/IMC conduit. It is violation of Section 110.3 (B) to use steel locknut with PVC conduit sch 40.

 

[Dennis Alwon]

I don't see the problem as long as the box is grounded if it is metal. I cannot see an issue with a metal locknut on PVC as long as it is inside the box. Many carflex fittings come with metal locknuts while others use plastic.

 

[kwired]

Steel locknut is listed for use with Rigid/IMC conduit. It is violation of Section 110.3 (B) to use steel locknut with PVC conduit sch 40.

There are lots of nonmetallic fittings that come supplied with a metal locknut, are you sure of this?

 

[don_resqcapt19]

250.4(A)(2) requires that the metal locknut used on a non-metallic system be bonded.

 

[squaredan]

250.4(A)(2) requires that the metal locknut used on a non-metallic system be bonded.

HI Don,

Is that from 2011, if so would that be the same as 250.4A3 in 2008?

 

[Dennis Alwon]

and A(3) states that electrical conductive material likely to be energized shall be bonded. Really do we really think that the locknut is likely to get energized and if it did it would be inside the box. Where is the danger?

 

[squaredan]

and A(3) states that electrical conductive material likely to be energized shall be bonded. Really do we really think that the locknut is likely to get energized and if it did it would be inside the box. Where is the danger?

They could use bonding locknuts but I agree with you Dennis..I was just asking what code cycle because I dont see any mention of metal lock nuts on non-metallic systems to be bonded..I do see non-current conductive materials connected together(bonded) to the Electrical supply source to establish Eff- ground fault path back to the source...
Wondering if it was a code change...

Dan

 

[Dennis Alwon]

They could use bonding locknuts but I agree with you Dennis..I was just asking what code cycle because I dont see any mention of metal lock nuts on non-metallic systems to be bonded..I do see non-current conductive materials connected together(bonded) to the Electrical supply source to establish Eff- ground fault path back to the source...
Wondering if it was a code change...

Dan

There is no mention of metal locknuts but it is included in electrical equipment. The question is what is meant by electrical equipment. IMO it can include everything but I am not sure that is the intent. I don't think of a locknut when I think of equipment but that means nothing.

 

[Gregg Harris]

They could use bonding locknuts but I agree with you Dennis..I was just asking what code cycle because I dont see any mention of metal lock nuts on non-metallic systems to be bonded..I do see non-current conductive materials connected together(bonded) to the Electrical supply source to establish Eff- ground fault path back to the source...
Wondering if it was a code change...


250.4 General Requirements for Grounding and Bonding.


(A) Grounded Systems.


Dan

(2) Grounding of Electrical Equipment. Normally non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials.

I do not see it applying to the lock nut

 

[Dennis Alwon]

(2) Grounding of Electrical Equipment. Normally non?current-carrying conductive materials enclosing electrical conductors or equipment, or forming part of such equipment, shall be connected to earth so as to limit the voltage to ground on these materials.

I do not see it applying to the lock nut

Again what is electrical equipment. Is the locknut electrical equipment????

 

[squaredan]

Again what is electrical equipment. Is the locknut electrical equipment????

I am going to say Yes Art 100 defines Equipment as a general term including materials, FITTINGS...ect, So I will say yes..I still dont see NON METALLIC systems though..

Dan

 

[Dennis Alwon]

I am going to say Yes Art 100 defines Equipment as a general term including materials, FITTINGS...ect, So I will say yes..I still dont see NON METALLIC systems though..

Dan

We are talking the metallic locknut on a pvc connector