wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
Surely for 690.31(D) you need to transition on the outside face of the exterior wall, not the inside face? Unless the exception for PVHCS applies?
Cheers, Wayne
PVC to EMT
- Thread starter solarken
- Start date
Cheers, Wayne
solarken
NABCEP PVIP
- Location
- Hudson, OH, USA
- Occupation
- Solar Design and Installation Professional
I am not sure that is clear. If the intent is to protect emergency personnel during a fire from contacting energized DC, then transitioning right where it penetrates the fire barrier, i.e. the drywall would achieve that.
wwhitney
Senior Member
- Location
- Berkeley, CA
- Occupation
- Retired
But a corollary of that would be that you could run PVC inside the wall as far as you like, which I would think is clearly "inside the building".
Cheers, Wayne
- Location
- Illinois
- Occupation
- retired electrician
I thought we were talking about the threads on the connector...no idea nuts and bolts had entered the conversation
All wiring methods require the use of listed wiring methods and associated fittings.
.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
We are talking about female NPS threads and male NPT threads making a mechanical connection.
I am not saying the OP is compliant, I am addressing the "not evaluated" statement. For example could the OP be used as a chase for cables not as a complete raceway?
- Location
- Illinois
- Occupation
- retired electrician
First, very few connectors have NPT threads as the product standard does not require that. The product standard does not require that the connector be tested for uses other than with a locknut. Will it be suitable? Very likely. Will the AHJ accept it? Only your AHJ can answer that.
For the record, well over 95% of the LFMC connectors that were installed by me or my guys, were threaded into fittings having female threads, and I expect that is the case for most all industrial installations.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
IMO yes. Some inspectors will still try to make you change it claiming it isn't listed for the use. I sometimes get one telling me I can't use something against it's listing when the item isn't required to be listed to begin with.
Eddie702
Licensed Electrician
- Location
- Western Massachusetts
- Occupation
- Electrician
Although I see nothing wrong with using a threaded coupling to go from 1 wiring method to another, I guess it is a no-no and IMHO is one of the dumbest code rules I can think of. This has been done for years before the "listed transition" fittings were a thing. You can find examples of it everywhere especially on older jobs. I doubt there has ever been a single failure of any type because of it.
But my opinion is nothing.
You could use a box or probably a "C" or "L" fitting as well.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Transition fittings been around for a long time, at least certain ones have. I occasionally have found some transition fittings in older work that were very likely part of the original install.
One such recollection was a mid 1960's constructed building and encountering some RMC to EMT compression couplings on lines that should been part of original construction. RMC emerged from on grade slab and was adapted to EMT that was run above grade.
going_commando
Member
- Location
- NH
We keep a box of 3/4 RMC to EMT fittings. They are EMT compression on one side and female threaded on the other. Very handy things, but not really any better than a 3/4" compression connector screwed into a rigid coupling. It's all very silly, and I rarely use listed transition fittings, as in most cases they don't exist or aren't easily available. If manufacturers just made connectors with NPT threads, all of this would be solved, but since that would cost more money since they would have to add an extra 1/2 oz of metal to have enough thickness to install a tapered thread than I guess I'll just keep violating listing and labelling instructions. It's very silly that PVC fittings have the most expansive listing, considering they are the most fragile fittings. Due to the nature of the work that we do, I don't run a whole lot of PVC, but everywhere I see broken pvc pipe or fittings, or pvc wobbling its way down a wall.
I also don't know what's changed, but it seems to me that PVC conduit is substantially harder to pull wire through than it used to be. I'm using way more pulling lube that I ever used to. Same with carflex. I hate the mess that pulling lube adds, but its basically a necessity when I wire a carwash in PVC and carflex, even though I am not maxing out conduit fill.
I also don't know what's changed, but it seems to me that PVC conduit is substantially harder to pull wire through than it used to be. I'm using way more pulling lube that I ever used to. Same with carflex. I hate the mess that pulling lube adds, but its basically a necessity when I wire a carwash in PVC and carflex, even though I am not maxing out conduit fill.
- Location
- Illinois
- Occupation
- retired electrician
You won't find that as a rule in the NEC. The closest would be 110.3(B), but the NEC itself has nothing to say about this. It is an issue with connectors not having been evaluated for use with female threads. However that is changing...there is at least one LFMC connector manufacturer that uses NPT threads and those can be used with female threaded fittings. I don't think there are any EMT connectors with NPT threads.
readydave8
re member
- Location
- Clarkesville, Georgia
- Occupation
- electrician
Lotsa things harder for me than they used to be
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
