Ko above the level of the bus bar

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jwjrw

jwjrw

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I saw an outside service today that had a ko cut above and to the left of the bus bar. I was told one time that you couldn't do that because water could enter the panel somehow. I looked at the places I thought it might say this but can't find it. Pass or fail and art # please.
 
Dennis Alwon said:
Was there a myers hub or weathertite locknuts?
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I saw neither. The electrician doing the job across the street told me the inspector said he couldnt do it even with a sealing loc knut. I told him I didnt see anything in the code( I did miss the sealing lock nut )that said he couldn't do it.
 
jwjrw said:
I saw neither. The electrician doing the job across the street told me the inspector said he couldnt do it even with a sealing loc knut. I told him I didnt see anything in the code( I did miss the sealing lock nut )that said he couldn't do it.
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The inspector is incorrect. Here's the relavant code section:

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 (?-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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Actually, it depends on the application. I believe it was Don, the mod, who stated the UL book does not accept the sealing locknut for anything other than RMC conduit. That was news to me.
 
This is from the UL book. The red area may be your saving grace here.

Sealing Locknuts — Sealing locknuts are intended for use with threaded rigid metal conduit and intermediate metal conduit with one sealing locknut in the outside or the inside and either an ordinary locknut or sealing locknut on the opposite side of the enclosure for wet locations or liquid-tight applications. Sealing locknuts may also be used with Listed wet location or liquid-tight fittings where so marked on the fitting carton.
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Here is something from steel city on their sealing locknuts.
3/4" Steel Sealing Locknut-Zinc Plated. For use with Rigid/IMC Conduit.
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I'm still unclear how you would treat a K.O. in a 3R enclosure not containing live parts. Do you never have to use sealing fittings, or do you always have to? Read 314.15.
 
After a little thought I think that sealing locknuts or myer hubs would be required on any 3r enclosure that is just a JB. Why? I am not sure but 312.2 seems to give some relief for cabinets, etc if you are below the buss. There does not seem to be any relief for say a PVC JB.
 
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