Terminating Romex in a PVC Junction Box

Status
Not open for further replies.
M

mkgrady

Senior Member
Location
Massachusetts
I'm stumped. I am running Romex to a pvc weatherproof junction box.....the kind you would install outdoors with a gasket but I'm installing it indoors. The box is a junction point between a generator and an ats. I'll be terminating 2 14-3 Romex, one #3SER and one 1-1/2" pvc. Drilling the holes exactly where I need them is easy and the reason I like Pvc. The ser connector is no problem and the ser connector is just long enough but the Romex connecter is too short.

The walls of the box are thick....maybe about 3/8"....just thick enough so that a standard Romex connectors throat is not long enough to get a locknut installed. The button type connectors that snap in place don't work either because the material is too thick. I could use a sheet metal box but is just harder to work with. Any ideas?
 
B

bristlepad

Member
Location
Jacksonville Florida
Different brands of connectors have different thread lengths. I run in to this problem all the time. Try some different brands. You may have to dig up an old school one as they used to be made a little longer


Sent from my iPad using Tapatalk
 
W

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
mkgrady said:
The walls of the box are thick....maybe about 3/8"....just thick enough so that a standard Romex connectors throat is not long enough to get a locknut installed. The button type connectors that snap in place don't work either because the material is too thick. I could use a sheet metal box but is just harder to work with. Any ideas?
Click to expand...
Counterbore the wall of the box for the locknut or the button connector?

Cheers, Wayne
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
mkgrady said:
I'm stumped. I am running Romex to a pvc weatherproof junction box.....the kind you would install outdoors with a gasket but I'm installing it indoors. The box is a junction point between a generator and an ats. I'll be terminating 2 14-3 Romex, one #3SER and one 1-1/2" pvc. Drilling the holes exactly where I need them is easy and the reason I like Pvc. The ser connector is no problem and the ser connector is just long enough but the Romex connecter is too short.

The walls of the box are thick....maybe about 3/8"....just thick enough so that a standard Romex connectors throat is not long enough to get a locknut installed. The button type connectors that snap in place don't work either because the material is too thick. I could use a sheet metal box but is just harder to work with. Any ideas?
Click to expand...

How are you grounding the metal NM connectors?

I strongly suggest using a metal box.
 
Ponchik

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
K8MHZ said:
I was thinking the same thing.
Click to expand...


Didn't cross my mind that the connector has to be connected to an EGC. Found the section in the book.

I now agree with others, use a metallic box.
 
G

GerryB

Senior Member
Location
woodbridge, ct. USA
Canton said:
Use all of the above except the chase nipple, instead use a close nipple inside the box with lock ring. Then as I wire said you have to bound the metallic connectors. Put a bond bushing. As already said I would use a metal box.
Click to expand...
I have never been called on bonding metal connectors in plastic or pvc boxes, you probably need to, what about the ser locknut? Could you use a half or 3/4 pvc ta, put both 14-3's in it, secure near box and maybe a little duct seal or silicone in the ta? Crazy maybe but romex cables wind up not being secured in many boxes after you punch the tab and it falls out.
 
Last edited:
Ponchik

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
mkgrady said:
What section did you find?
Click to expand...

250.4(A)(4)

(4) Bonding of Electrically Conductive Materials and
Other Equipment. Normally non?current-carrying electrically
conductive materials that are likely to become energized shall
be connected together and to the electrical supply source in a
manner that establishes an effective ground-fault current path.
 
M

mkgrady

Senior Member
Location
Massachusetts
edward said:
250.4(A)(4)

(4) Bonding of Electrically Conductive Materials and
Other Equipment. Normally non?current-carrying electrically
conductive materials that are likely to become energized shall
be connected together and to the electrical supply source in a
manner that establishes an effective ground-fault current path.
Click to expand...

Thanks for posting that. Now for a discussion. In this pvc box where I plan to use metal Romex connectors, metal ser connectors, metal locknuts and metal screws to hold it in place, is it LIKELEY that they will become energized?

I can use bonding bushings to bond the ser and Romex connectors but how am I to bond the locknut of the male adapter? How am I to bond the screws that hold the box to the wall?
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
mkgrady said:
Thanks for posting that. Now for a discussion. In this pvc box where I plan to use metal Romex connectors, metal ser connectors, metal locknuts and metal screws to hold it in place, is it LIKELEY that they will become energized?
Click to expand...

It does not matter if it is likely to become energized or not. This is the section I would cite.

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

Connectors are equipment per NEC definition.

I can use bonding bushings to bond the ser and Romex connectors but how am I to bond the locknut of the male adapter? How am I to bond the screws that hold the box to the wall?
Click to expand...

If you can't see an oblivious differance between an exposed metal fitting clamping down on NM and a mounting screw that is totally enclosed I would say we are too far apart to agree.

As far as the lock nut .... MAs are made to thread into threaded holes, truthfully I think the NEC requires that locknut to be bonded.
 
G

GerryB

Senior Member
Location
woodbridge, ct. USA
I don't think bonding is required. I am pretty sure you are not even required to use a plastic bushing on SER or SEU cable, like in a service, because of the sheathing, which is to extend past the connector which makes becoming energized more unlikely. Same with the romex sheathing. I would love to see what this box looks like when you are done with it:D
 
Ponchik

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
mkgrady said:
Thanks for posting that. Now for a discussion. In this pvc box where I plan to use metal Romex connectors, metal ser connectors, metal locknuts and metal screws to hold it in place, is it LIKELEY that they will become energized?

I can use bonding bushings to bond the ser and Romex connectors but how am I to bond the locknut of the male adapter? How am I to bond the screws that hold the box to the wall?
Click to expand...

There is a chance but I don't know how likely it is that an energized wire comes loose and touches the metal connector. But there is a chance.
 
M

mkgrady

Senior Member
Location
Massachusetts
iwire said:
It does not matter if it is likely to become energized or not. This is the section I would cite.



Connectors are equipment per NEC definition.



If you can't see an oblivious differance between an exposed metal fitting clamping down on NM and a mounting screw that is totally enclosed I would say we are too far apart to agree.

As far as the lock nut .... MAs are made to thread into threaded holes, truthfully I think the NEC requires that locknut to be bonded.
Click to expand...

I do see a difference and I'm not disagreeing. I'm just asking questions to improve my code knowledge.

I don't see a way to bond the locknut on a male adapter. If there isn't a way to bond it then it must not be permissible to drill a hole in a nonmetallic box and run pvc into it. If that is true then only bonded metallic connectors can be used on nonmetallic boxes and male adapters can not be used in a code compliant way?
 
iwire

iwire

Moderator
Staff member
Location
Massachusetts
GerryB said:
I don't think bonding is required.
Click to expand...

Let me ask you this, what code section requires EMT to be grounded?:)

Does that section exempt fittings and NM connectors from it?


I am pretty sure you are not even required to use a plastic bushing on SER or SEU cable, like in a service, because of the sheathing, which is to extend past the connector which makes becoming energized more unlikely. Same with the romex sheathing.
Click to expand...

Now that I agree with 100% and here is the code section.

300.4(G) Insulated Fittings. Where raceways contain 4 AWG
or larger insulated circuit conductors, and these conductors
enter a cabinet, a box, an enclosure, or a raceway, the conductors
shall be protected by an identified fitting providing
a smoothly rounded insulating surface, unless the conductors
are separated from the fitting or raceway by identified
insulating material that is securely fastened in place.
Click to expand...

Notice it is for raceways not cables. :)
 
Status
Not open for further replies.
Top