Corysix7
Member
- Location
- Lakeland florida USA
Is it allowable to use a running threaded nipple with a bonding bushing that contains service conductors installed at a meter can enclosure?
Running threads
- Thread starter Corysix7
- Start date
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hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
Yes, or are you saying no locknuts between the cans?
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
The only prohibition of running thread is at couplings, in art 342 and 344. When I was working I used to keep some on hand as it was handy for some jobs, but very expensive.
For your application, you can't use PVC and TAs?
For your application, you can't use PVC and TAs?
Corysix7
Member
- Location
- Lakeland florida USA
The application this was used in was for a 120/208 wye 400 amp service change out and the company popped out the bottom of meter enclosure with running thread nipple into a conduit body for the service raceway and I knew of not using the running threads for IMC and RMC at couplings and knew of it no where else in code but I know the theory behind not using the running threads at couplings under a fault condition so didn't know if that would have the same theory behind this application.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
They're permitted just not at a coupling as Tom stated. Back in the day we used to make these for deck work which took place of an Erickson type 3-piece coupling which the boss refused to buy because the were expensive. These are much cheaper and faster although technically not permitted. No one seems to care since it was getting buried in concrete.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Are ericksons even permitted below grade? Not concrete but in the earth. I didn't think they were
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Why shouldn't they be? Like the conduit or the regular coupling they have threads and they have galvanizing they shouldn't really have much different effects from environment than use of a regular coupling.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I know what I was thinking. I was thinking of the threadless fitting. I believe they are not rated for wet location.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I think that we've discussed that before but since a standard coupling isn't water-tight either should it really matter?
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
It shouldn't but apparently it is important that EMT fittings are the newer rain tight type.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Good point, I wonder what the substantiation for that was, did it start as a UL listing thing?
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
IIRC someone decided the original compression fittings we commonly used were not actually rain tight, so they modified the design and included the nylon ferrule that is pretty typical and added a rubber washer to be used at the shoulder of connector fittings and got it listed, making it a violation of listing if you don't use this type of fitting for the application.
I stopped using the rubber washers after first year or so of those type being required. Come back to jobs I had done and find the washer deteriorated in the sunlight cracked, missing pieces, or even completely missing and finding a connection to the box that leaks more water than if I had used a set screw fitting, let alone it has no effective bonding to the box at all. I gone back to putting them into myers hubs to solve the sealing washer issue. They I do a lot of outdoor installations and can assure you there is more moisture inside from condensation than there is from leakage. Maybe in desert southwest not so much but definitely is here.
hbiss
EC, Westchester, New York NEC: 2014
- Location
- Hawthorne, New York NEC: 2014
- Occupation
- EC
I saw a recommendation to use silicon RTV as a thread compound and have been doing that instead of that useless washer. Shouldn't effect the bonding since you can sock it down. Haven't had the opportunity to go back anywhere to see if there was any leakage.
-Hal
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I'm sure it works, at least for longer time than the rubber washers. I'd bet not many inspectors would approve it though. I wouldn't think they can say too much if you install the rubber washer then put silicone over them.
- Status