# Double locknut and weatherproof installations



## MDShunk (Jan 7, 2007)

Is anyone aware of any specific language that would prohibit a double locknut entry of RMC/IMC into the top of enclosures in an outdoor environment, exposed to the weather? Even if the double locknut connection is miraculously not leaking for some reason? I can't seem to find anything specific in the NEC or the UL White Book, but I must not be searching right. 

Thanks.


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## HARRY304E (Sep 15, 2010)

MDShunk said:


> Is anyone aware of any specific language that would prohibit a double locknut entry of RMC/IMC into the top of enclosures in an outdoor environment, exposed to the weather? Even if the double locknut connection is miraculously not leaking for some reason? I can't seem to find anything specific in the NEC or the UL White Book, but I must not be searching right.
> 
> Thanks.


 specificly it does not say you cant do that .

That must be an oversite.:blink:


*
314.15 Damp or Wet Locations.​*​​​​In damp or wet locations,
boxes, conduit bodies, and fittings shall be placed or
equipped so as to prevent moisture from entering or accumulating​
within the box, conduit body, or fitting. Boxes,

conduit bodies, and fittings installed in wet locations shall
be listed for use in wet locations.​Informational Note No. 1: For boxes in floors, see
314.27(B).
Informational Note No. 2: For protection against corrosion,​see 300.6
*
342.42 Couplings and Connectors.
(A) Threadless.​*​​​​Threadless couplings and connectors used
with conduit shall be made tight. Where buried in masonry
or concrete, they shall be the concretetight type. Where
installed in wet locations, they shall comply with 314.15.
Threadless couplings and connectors shall not be used on​
threaded conduit ends unless listed for the purpose.

*
344.42 Couplings and Connectors.
(A) Threadless.​*​​​​Threadless couplings and connectors used
with conduit shall be made tight. Where buried in masonry
or concrete, they shall be the concretetight type. Where
installed in wet locations, they shall comply with 314.15.
Threadless couplings and connectors shall not be used on​
threaded conduit ends unless listed for the purpose


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## ce2two (Oct 4, 2008)

HARRY304E said:


> specificly it does not say you cant do that .
> 
> That must be an oversite.:blink:
> 
> ...



I'm surprised you didn't mention a myers hub...:no:Use a freakin myers hub, now put down the :drink: no more hicuuuups?:laughing:I hate when knuckle heads go without myers hubs IMO?​


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## HARRY304E (Sep 15, 2010)

ce2two said:


> I'm surprised you didn't mention a myers hub...:no:Use a freakin myers hub, now put down the :drink: no more hicuuuups?:laughing:I hate when knuckle heads go without myers hubs IMO?
> [/left]


You need somthing a little stronger..:laughing:


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## ce2two (Oct 4, 2008)

HARRY304E said:


> You need somthing a little stronger..:laughing:


 I can see your liver is bleeding from the hard stuff......Your eyes are still blood shot? your experience is showing?YOU LOVE MOON SHINE DON'T YOU ....COME ON IT'S OUR DIRTY LITTLE SECRET?


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## HARRY304E (Sep 15, 2010)

ce2two said:


> I can see your liver is bleeding from the hard stuff......Your eyes are still blood shot? your experience is showing?YOU LOVE MOON SHINE DON'T YOU ....COME ON IT'S OUR DIRTY LITTLE SECRET?


No *Double locknut 's for you..:thumbup::laughing:*


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## ce2two (Oct 4, 2008)

HARRY304E said:


> No *Double locknut 's for you..:thumbup::laughing:*


 NOW that was a weak come back:thumbup:Hard to wrestle with an unarmed man:laughing:


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## HARRY304E (Sep 15, 2010)

ce2two said:


> NOW that was a weak come back:thumbup:Hard to wrestle with an unarmed man:laughing:


I hope you get a Good nights ..:sleep1::sleep1::sleep1::laughing:


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## ce2two (Oct 4, 2008)

HARRY304E said:


> I hope you get a Good nights ..:sleep1::sleep1::sleep1::laughing:


 I have 55 mile training ride in the morning can't wait...Need to watch my figure....:laughing:saturday and sunday ?


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## goose134 (Nov 12, 2007)

Ever try these?









Sealing locknuts are nice, raintight solution to a lot of conduit entry problems.


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## MDShunk (Jan 7, 2007)

goose134 said:


> Ever try these?
> 
> Sealing locknuts are nice, raintight solution to a lot of conduit entry problems.


Sure. I'm evaluating an existing installation is why I'm asking.

Sent from my iPhone using the ElectricianTalk Forum app


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## Dennis Alwon (May 9, 2009)

Article 312 for cabinets and meter enclosures



> 312.2 Damp and Wet Locations.
> In damp or wet locations, surface-type enclosures within the scope of this article shall be placed or equipped so as to prevent moisture or water from entering and accumulating within the cabinet or cutout box, and shall be mounted so there is at least 6-mm (¼-in.) airspace between the enclosure and the wall or other supporting surface. Enclosures installed in wet locations shall be weatherproof. For enclosures in wet locations, raceways or cables entering above the level of uninsulated live parts shall use fittings listed for wet locations.
> Exception: Nonmetallic enclosures shall be permitted to be installed without the airspace on a concrete, masonry, tile, or similar surface.


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## BBQ (Nov 16, 2010)

> 312.2 Damp and Wet Locations.
> 
> In damp or wet locations, surface-type enclosures within the scope of this article shall be placed or equipped so as to prevent moisture or water from entering and accumulating within the cabinet or cutout box, and shall be mounted so there is at least 6-mm (¼-in.) airspace between the enclosure and the wall or other supporting surface. Enclosures installed in wet locations shall be weatherproof. *For enclosures in wet locations, raceways or cables entering above the level of uninsulated live parts shall use fittings listed for wet locations.
> *
> ...




I don't think standard locknuts are listed for wet locations. :no:


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## MDShunk (Jan 7, 2007)

BBQ said:


> I don't think standard locknuts are listed for wet locations. :no:


I've been looking this up a bit. 

Locknuts of any type are covered in the UL White Book under DWTT. The only locknuts in that section listed for wet locations are sealing locknuts. Plain locknuts are out (which is logical), but I'm faced with a unique situation where a good many exist that way, and few are leaking or show signs of corrosion.


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## BBQ (Nov 16, 2010)

MDShunk said:


> I've been looking this up a bit.
> 
> Locknuts of any type are covered in the UL White Book under DWTT. The only locknuts in that section listed for wet locations are sealing locknuts. Plain locknuts are out (which is logical), but I'm faced with a unique situation where a good many exist that way, and few are leaking or show signs of corrosion.



It seems if your evaluating an existing installation you would just say something like...


_'Dry location fittings used in many wet locations. This an NEC violation, the current condition shows little deterioration' _ 


...now the customer can decide what to do and you have covered your ass. (IMO)


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## MDShunk (Jan 7, 2007)

BBQ said:


> It seems if your evaluating an existing installation you would just say something like...
> 
> 
> _'Dry location fittings used in many wet locations. This an NEC violation, the current condition shows little deterioration' _
> ...


Probably exactly what I'll do. In two cases, interestingly, the connection measures 100% dielectric, but they appear to be made up tight. The pipe is the ground.  I think I'll note those specially. They appear to be die cast locknuts, in case anyone is wondering.


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## Dennis Alwon (May 9, 2009)

I wonder if silicone or duct seal would satisfy code.


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## MDShunk (Jan 7, 2007)

Dennis Alwon said:


> I wonder if silicone or duct seal would satisfy code.


I was thinking the same thing, but silicone or duct seal does not appear to be a listed fitting. There doesn't seem to be any relief, that I have found, from using listed fittings if you smear something over fittings not listed for wet locations.

edit... in dairy work, sometimes custom enclosures have couplings TIG welded to the tops of enclosures (often in stainless work), for top entries. These might be called hubs that are part of a UL listed or field evaluated enclosure? I dunnno. Just taking this thing to its logical progression.


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## Dennis Alwon (May 9, 2009)

That is correct-- it does say listed fitting. Since it is existing I was wondering that for a quick fix, esp. since it is not leaking anyway.


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## MDShunk (Jan 7, 2007)

Dennis Alwon said:


> That is correct-- it does say listed fitting. Since it is existing I was wondering that for a quick fix, esp. since it is not leaking anyway.


I ain't doin that at this point. I'm shooting for the cha-ching. :thumbsup:


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## mike8487 (Mar 29, 2011)

its a good question. but let me answer this by posing another. What Nema rating in the enclosure you saw these locknuts?


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## MDShunk (Jan 7, 2007)

mike8487 said:



> its a good question. but let me answer this by posing another. What Nema rating in the enclosure you saw these locknuts?


3R and 4X. Most were 4X JIC enclosures. 

Sent from my iPhone using the ElectricianTalk Forum app


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## mike8487 (Mar 29, 2011)

i think the only way you can comply with nema 3r is to use hubs. it makes no sense to me use locknuts on Nema 3r and 4x equipment if you want to stay consistent with that level of quality. now if you said it was Nema 1, then i would understand why locknuts were used.


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## gnxtc2 (Feb 21, 2011)

The problem with the 2 piece hubs (where one end screws inside the body), how do you get a bond on it? I heard that there is a provision to attach a lug but never saw one.

Billy T.
[email protected]


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## MDShunk (Jan 7, 2007)

gnxtc2 said:


> The problem with the 2 piece hubs (where one end screws inside the body), how do you get a bond on it? I heard that there is a provision to attach a lug but never saw one.
> 
> Billy T.
> [email protected]


Seldom are you actually required to specially bond that fitting (maybe only when using a metallic hub to bring a metallic raceway into a nonmetallic enclosure), but when you are, there are Meyers hubs with tapped holes at intervals around the huge locknut they come with. Generally tapped 10-32. Not the standard Meyers Hub. You need to specify the bonding type.


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## MDShunk (Jan 7, 2007)

mike8487 said:


> i think the only way you can comply with nema 3r is to use hubs. it makes no sense to me use locknuts on Nema 3r and 4x equipment if you want to stay consistent with that level of quality. now if you said it was Nema 1, then i would understand why locknuts were used.


Got anything to back that up? I read all I could on NEMA's site about enclosure ratings, and nothing specified the use of hubs to maintain a particular rating.


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## BBQ (Nov 16, 2010)

mike8487 said:


> i think the only way you can comply with nema 3r is to use hubs. it makes no sense to me use locknuts on Nema 3r and 4x equipment if you want to stay consistent with that level of quality. now if you said it was Nema 1, then i would understand why locknuts were used.


If you come in below the live parts of a 3R enclosure you do not need a wet location fitting.

If you come in above the live parts hubs are one option, sealing locknuts or sealing washers are other code compliant options.


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## MDShunk (Jan 7, 2007)

BBQ said:


> If you come in below the live parts of a 3R enclosure you do not need a wet location fitting.
> 
> If you come in above the live parts hubs are one option, sealing locknuts or sealing washers are other code compliant options.


But baby seals, on the other hand, are not one of the options.


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## BBQ (Nov 16, 2010)

MDShunk said:


> But baby seals, on the other hand, are not one of the options.


If they are listed baby seals I see no problem.


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## Big John (May 23, 2010)

I think 314.15(A) covers it well enough. They will leak. It's pretty plain. If your customer thinks they won't, then pour a jug of water over the top of the enclosure then look inside.

Even with hubs, I despise penetrations through the top of enclosures in damp/wet locations, they'll leak no matter how you try to seal them, and I'll go a distance out of my way to avoid making them.

-John


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## Rockyd (Apr 22, 2007)

BBQ said:


> If you come in below the live parts of a 3R enclosure you do not need a wet location fitting.
> 
> If you come in above the live parts hubs are one option, sealing locknuts or sealing washers are other code compliant options.


Evaluating the sum total, I think the place you're inspecting was never code compliant to begin with in regard to fittings. So it gets down to patching trash, vs potentially serious bucks for a rework of "some" pipework. What kind of area is it? Risk analysis of what is at stake is a play also.

Sounds like the place missed from the original construction point because of a low baller, and now they know they are having to pay the price.This should have been considered back with the engineering, and construction of the initial build out. Same owner, or are you evaluating for a potential buyer? Ohh the head games of selling the money:whistling2:

Somewhere between Robroy, and IMC going into Myers hubs with grounding provisions lies the answer....


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## MDShunk (Jan 7, 2007)

It's actually an indoor wet location. Car wash. The reason for being there was because of an injury.


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## heel600 (Oct 31, 2007)

MDShunk said:


> I was thinking the same thing, but silicone or duct seal does not appear to be a listed fitting. There doesn't seem to be any relief, that I have found, from using listed fittings if you smear something over fittings not listed for wet locations.
> 
> edit... in dairy work, sometimes custom enclosures have couplings TIG welded to the tops of enclosures (often in stainless work), for top entries. These might be called hubs that are part of a UL listed or field evaluated enclosure? I dunnno. Just taking this thing to its logical progression.


but if the silicone completely covers the fitting/locknut, then it would not be exposed to the rain. So then it would be a damp location.

I'm not saying I'd do it. I'm just saying.


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## MDShunk (Jan 7, 2007)

heel600 said:


> but if the silicone completely covers the fitting/locknut, then it would not be exposed to the rain. So then it would be a damp location.
> 
> I'm not saying I'd do it. I'm just saying.


A wet location is still a wet location, no matter how much silicone you put on it. Just because you put on a coat to go outside doesn't mean you're still inside. :laughing:


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## mike8487 (Mar 29, 2011)

MDShunk said:


> Got anything to back that up? I read all I could on NEMA's site about enclosure ratings, and nothing specified the use of hubs to maintain a particular rating.


actually no. but let me ask you. what would you use? remember that it has to stay watertight. or water repellant.


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## BBQ (Nov 16, 2010)

mike8487 said:


> actually no. but let me ask you. what would you use? remember that it has to stay watertight. or water repellant.


I use sealing lock nuts often, they are code compliant and keep the water out.

For some reason many electricians seem to get a woody over hubs .....I am not one of them.


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## mike8487 (Mar 29, 2011)

BBQ said:


> I use sealing lock nuts often, they are code compliant and keep the water out.
> 
> For some reason many electricians seem to get a woody over hubs .....I am not one of them.


hubs cost money, no doubt. i would use sealing locknuts too. i actually prefer to use sealing washers. but if the spec calls for hubs then you are stuck with them.


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## Mike in Canada (Jun 27, 2010)

BBQ said:


> I use sealing lock nuts often, they are code compliant and keep the water out.
> 
> For some reason many electricians seem to get a woody over hubs .....I am not one of them.


 The seals that I use are quite similar to the sealing lock nuts but they're un-threaded. They're meant to be held in place by a separate standard lock nut. I prefer them because you can get them snugger without wrecking the seal. With the sealing lock nut the rubber has to rub against the enclosure to tighten up. With the sealing ring it's rubber-to-enclosure, not moving, and metal-to-metal between the ring and lock-nut as the sliding surface.


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## John (Jan 22, 2007)

I read the entire thread twice and the summation of the entire thread boils down to workmanship and experiance as what is the correct way. Appears that the only sure way to call it would be  110.12.
I would not use just regular lock nuts for installing conduit into the top of 3R or 4X enclosures, botton of....maybe.


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## sbrn33 (Mar 15, 2007)

This doesn't help your situation but when I do a car wash I use nothing but shed 80 pvc, pvc boxes, rmc on the floor and carflex. Anything else will rust, leak and just plain look bad in a year or less. Even stainless screws are a good idea.


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## Wirenuting (Sep 12, 2010)

BBQ said:


> I use sealing lock nuts often, they are code compliant and keep the water out.
> 
> For some reason many electricians seem to get a woody over hubs .....I am not one of them.


We used them alot here. I found that they last about 10 years before they dry rot. 
I keep them out of the sun & mount the device on a slight angle so water runs off. Also the box & pipe has to be mounted securely so the rubber doesn't move at all.


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## BBQ (Nov 16, 2010)

The funny thing is hubs are only listed for use with threaded conduit, when you screw in a connector (compression EMT, PVC MA etc) you have a violation.


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## Big John (May 23, 2010)

BBQ said:


> The funny thing is hubs are only listed for use with threaded conduit, when you screw in a connector (compression EMT, PVC MA etc) you have a violation.


 Why? Straight thread VS taper...?

-John


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## MDShunk (Jan 7, 2007)

Big John said:


> Why? Straight thread VS taper...?
> 
> -John


Not sure, but you can read it for yourself in the UL White Book. I would have to think that this is an oversight.


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