Flexible Metalic Conduit
- Thread starter sparky88
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
Re: Flexible Metalic Conduit
Yes.
Yes.
bphgravity
Senior Member
- Location
- Florida
Re: Flexible Metalic Conduit
Review 348.12 Uses Not Permitted, just in case.
Review 348.12 Uses Not Permitted, just in case.
shocker3218
Senior Member
Re: Flexible Metalic Conduit
Not in Lincoln, Nebraska. Flex conduit is only permitted in legths of 6ft or less, where needed for flexibility, or fished in a wall. Flex is not an approved wiring method here. Which makes get creative in bending conduit is wood or metal stud walls.
by the way, MC and BX are not allowed at all.
I did a restaraunt where the kitchen equipment came pre-wired with flex and MC, and I had to redo it all, even though it came in as a UL listed assembly.
Not in Lincoln, Nebraska. Flex conduit is only permitted in legths of 6ft or less, where needed for flexibility, or fished in a wall. Flex is not an approved wiring method here. Which makes get creative in bending conduit is wood or metal stud walls.
by the way, MC and BX are not allowed at all.
I did a restaraunt where the kitchen equipment came pre-wired with flex and MC, and I had to redo it all, even though it came in as a UL listed assembly.
shocker3218
Senior Member
Re: Flexible Metalic Conduit
It dates back before my time, but what I am told is that is basically was due to a lot of bad installations and modifications. For instance, people (hopefully not electricians) would use the green wire if they needed an additonal conductor. They also feel that flex pulled apart too easily and you would loose your grounding path, assuming the ground conductor was either not installed, or used for something different.
I have found through experience that the AHJ's are very willing to work with you, if they know your work. I had 1 inspector that told us it was ok to use flex under racks at a department store, but would not allow squeeze flex connectors because no matter how hard you tightened them up, you could twist the flex out of the connector.
Have also seen out of town contractors try to use 200 ft of flex above a grid ceiling (not strapped in any way) for a 277 volt lighting homerun. It is installs such as this that makes our city (and also state) prohibit flex.
Shocker
It dates back before my time, but what I am told is that is basically was due to a lot of bad installations and modifications. For instance, people (hopefully not electricians) would use the green wire if they needed an additonal conductor. They also feel that flex pulled apart too easily and you would loose your grounding path, assuming the ground conductor was either not installed, or used for something different.
I have found through experience that the AHJ's are very willing to work with you, if they know your work. I had 1 inspector that told us it was ok to use flex under racks at a department store, but would not allow squeeze flex connectors because no matter how hard you tightened them up, you could twist the flex out of the connector.
Have also seen out of town contractors try to use 200 ft of flex above a grid ceiling (not strapped in any way) for a 277 volt lighting homerun. It is installs such as this that makes our city (and also state) prohibit flex.
Shocker
bphgravity
Senior Member
- Location
- Florida
Re: Flexible Metalic Conduit
All your examples above could be done with any wiring method. What is going to stop someone from inappropriately using conductors in NM cable or as single conductors in EMT or RNC? Any wiring method if not installed to code could present a hazard.
All your examples above could be done with any wiring method. What is going to stop someone from inappropriately using conductors in NM cable or as single conductors in EMT or RNC? Any wiring method if not installed to code could present a hazard.
A
a.wayne3@verizon.net
Guest
Re: Flexible Metalic Conduit
I have recently found a what I learned was called a chicago a way 3 conductors to a detached garage,a 3 way at each side and receptacles in the garage.As it turned out he shell base on the lampholder woud alternate from an ungrounded conductor to a grounded condutor in the base.That is swithing the neutral not allowed now but then its ok.
I have recently found a what I learned was called a chicago a way 3 conductors to a detached garage,a 3 way at each side and receptacles in the garage.As it turned out he shell base on the lampholder woud alternate from an ungrounded conductor to a grounded condutor in the base.That is swithing the neutral not allowed now but then its ok.
bphgravity
Senior Member
- Location
- Florida
Re: Flexible Metalic Conduit
I believe the system you are talking about is actually called the "Carter System". This system was in use back in the 1920's and soon became a code violation due to the switching of the white grounded conductor. I have a few vintage electrical books that describe this method in detail.
Re: Flexible Metalic Conduit
Here is an excellent graphic of a Chicago three way from Ronald Coleman. For those not familiar with Ronalds work, I suggest visiting Ronalds web site.
Bryan, you should contact Ronald for permission to use his work in your classes.
Roger
Here is an excellent graphic of a Chicago three way from Ronald Coleman. For those not familiar with Ronalds work, I suggest visiting Ronalds web site.
Bryan, you should contact Ronald for permission to use his work in your classes.
Roger
bphgravity
Senior Member
- Location
- Florida
Re: Flexible Metalic Conduit
Thanks Roger, I'll check it out!
Thanks Roger, I'll check it out!
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