The locknut violates the rule!

[Joe Tedesco]

312.2(A): For enclosures installed in wet locations, revised to require any cable or raceway that enters on the top or on the side above the level of uninsulated live parts in the enclosure be provided with fittings listed for wet locations.

Download Attachment: locknut.jpg

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[ozofprev]

Thanks Joe.

I can see where the lock-nut might allow for water intrusion, but how can the HI know that the lock-nut, combined with a particular grommet (for example) is not allowed?

IOW, can we assume that every lock-nut is a violation of the rules?

[Joe Tedesco]

Originally posted by ozofprev

Thanks Joe.

I can see where the lock-nut might allow for water intrusion, but how can the HI know that the lock-nut, combined with a particular grommet (for example) is not allowed?

IOW, can we assume that every lock-nut is a violation of the rules?

A locknut installed on the top of any enclosure in a wet location would not be permitted. All fittings that are used must be listed for wet locations.

http://www.nema.org/stds/fb2-10.cfm#download

[ozofprev]

Hmmm, any 'regular' locknut - correct?

I'm not trying to be trying, but this locknut (for wet locations) would be ok, no?

Download Attachment: wetLocknut.gif

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"Provides a watertight and dust tight NEMA 4X connection for rigid conduit and IMC into a knockout of a box or enclosure. Suitable for use indoors and outdoors, and in Class l, Div. 2, Class ll and Class lll Hazardous Locations. Available in trade sizes 1/2" though 4" with a standard or grounding locknut. Standard construction is zinc die cast with KO gasket and insulated throat. Chrome plating is optional."

[Joe Tedesco]

Your picture shows a "Meyers Hub" and it is the same type of fitting that is used in the picture I posted above.

Ordinary locknuts are not designed to be used in wet locations.

http://www.foxelectricsupply.com/conten ... ryId=25003

http://www.foxelectricsupply.com/conten ... ryId=25005

[PAbernathy]

Hey Joe..good to see you.....( sorry about the book thing..I got side tracked )

I think what joe is saying is the locknut itself is ok...the connector itself needs to be listed for wet locations. What compounds the issue is like in the first picture joe posted they used a locknut outside and before the actual waterproof connector..so the connector screwed into it just before it is not rated for wet locations at all....compounding the problem...

The entire connector needs to be rated for a wet location....would you agree Joe?

I think what it is trying to stop is the " what ever I have in the truck" mentality.....

[ozofprev]

Joe,

I'm just trying to prevent overgeneralization.

We don't need HI's out there screaming that every locknut is bad at hubs.

The locknut you pictured is NOT allowed.

The locknut in my picture IS allowed.

I love being wrong when I learn something, but so far, I haven't learned anything. I am NOT an electrician, so I'm sure there is something I am missing, not you.

My picture came from here...

http://www.o-zgedney.com/PDF/EB1thru3.pdf

[ozofprev]

Thanks Paul. It's all good.[:-thumbu]

[Joe Tedesco]

Originally posted by PAbernathy

Hey Joe..good to see you.....( sorry about the book thing..I got side tracked )

I think what joe is saying is the locknut itself is ok...the connector itself needs to be listed for wet locations. What compounds the issue is like in the first picture joe posted they used a locknut outside and before the actual waterproof connector..so the connector screwed into it just before it is not rated for wet locations at all....compounding the problem...

The entire connector needs to be rated for a wet location....would you agree Joe?

I think what it is trying to stop is the " what ever I have in the truck" mentality.....

Yes I agree Paul:

The identification of electrical materials, and using correct terms is often what confuses people. We need to develop an extensive pictorial list showing proper and improper uses of fittings.

The "Watertight Hubs" that were called "locknut's" here are what may be the problem.

I extracted the first page and the information, although showing "HazLoc" equipment does not call this fitting a locknut.

I have some more pictures showing the use of a fitting that was not designed for use in a wet location, trouble is I have so many of them it may take me a while.

I am in the middle of building my new 2008 NEC Show using a new machine with Vista, so far so good, better be! I need programs that will work.

I will have a backup XP machine with me just in case.

What do you mean here: "sorry about the book thing..I got side tracked"

Download Attachment: fitting.pdf

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[ozofprev]

The "Watertight Hubs" that were called "locknut's" here are what may be the problem.

I extracted the first page and the information, although showing "HazLoc" equipment does not call this fitting a locknut.

I didn't throw 'locknut' in there without reason. They say it is available with a standard or grounding locknut here (4th item down):

http://www.o-zgedney.com/whatsNew.htm

[Joe Tedesco]

Gary:

My original image showed the "upside down locknut" I was identifying and your comments took the discussion toward a special type of fitting and yes the "locknut" is as you described and as you stated.

The issue is that the ordinary simple locknut we use on threaded connections is not permitted to be used at the top of the entry into an outdoor enclosure where it would not provide a weather tight or "rain tight" termination, and the inside of the enclosure would have a locknut, or a locknut and bushing.

Think of it this way, the open knockout in the top of any box out of doors is never to be used with anything other that a listed fitting designed for that use.

[ozofprev]

Joe,

Understood.

I enjoy these discussions because specialists like you bring more depth to a particular subject, and I learn stuff while I'm looking things up. For example, 'rainproof' and 'raintight' - my intuition would have placed 'rainproof' as the more stringent term, but it turns out that 'raintight' is more stringent than 'rainproof'. Love to learn!

Thanks for your info! I hope you understood that I didn't want people to assume that things were automatically bad because they saw some sort of locknut. I think we've gotten past that now.[]

And best of luck in your current work.

[Frankie Boy]

In the picture it looks like a Meyers hub with typical Nema 1 locknut between the hub and a rigid threadless connector. If the conduit entering the hub is theaded,then it is not protected from moisture hence the word {threadless},but we don't know that the conduit is threaded or not. Now we have the problem of a Nema 1 locknut, this should have been a sealing locknut, if any at all. It has been my experience that if there is a hole water will find it.

Frank

[PAbernathy]

Joe....the contact on Holt's in PM about the old books....I was goign to reply but got side tracked and simply did not go back into the PM to see it.....and once you look once it does not pop up at you anymore so I kinda dropped the ball. I probably would not have gotten any...I bought so many off some auction sites the WIFE has be on CREDIT LOCK...

[Joe Tedesco]

Originally posted by PAbernathy

Joe....the contact on Holt's in PM about the old books....I was goign to reply but got side tracked and simply did not go back into the PM to see it.....and once you look once it does not pop up at you anymore so I kinda dropped the ball. I probably would not have gotten any...I bought so many off some auction sites the WIFE has be on CREDIT LOCK...

OK, I remembered after I asked you the question, anyway they are still here in my library along with over 30 years worth of collections looking for new homes:

1.) 1953 National Electrical Code, 42nd Anniversary Under NFPA Sponsor Ship, Hardback Volume V from the National Fire Codes, includes entire NEC, and original catalog of advertisers, and electrical provisions of other NFPA Standards.

2.) Electrical Code Diagrams, Volume I, by B. Z. Segall, 1952, Library of Congress Catalog Number: 51-12643, First Edition based on the 1951 edition of the National Electrical Code.

[Joe Tedesco]

Originally posted by Frankie Boy

In the picture it looks like a Meyers hub with typical Nema 1 locknut between the hub and a rigid threadless connector. If the conduit entering the hub is theaded,then it is not protected from moisture hence the word {threadless},but we don't know that the conduit is threaded or not. Now we have the problem of a Nema 1 locknut, this should have been a sealing locknut, if any at all. It has been my experience that if there is a hole water will find it.

Frank

Here's a good source for information:

http://www.nema.org/prod/be/conduit/