NM or MC to EMT change over
- Thread starter tkb
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jeff43222
Senior Member
- Location
- Minneapolis, Minnesota
Re: NM or MC to EMT change over
I don't see how you could go from NM or MC to EMT without splicing, and spicing has to be accessible.
NM can be sleeved in EMT under certain circumstances, but I'm not sure if the point of entry can be hidden inside a wall.
[ November 17, 2005, 07:51 PM: Message edited by: jeff43222 ]
I don't see how you could go from NM or MC to EMT without splicing, and spicing has to be accessible.
NM can be sleeved in EMT under certain circumstances, but I'm not sure if the point of entry can be hidden inside a wall.
[ November 17, 2005, 07:51 PM: Message edited by: jeff43222 ]
mdshunk
Senior Member
- Location
- Right here.
Re: NM or MC to EMT change over
You can go from Greenfield to EMT and bury that if you want to. The jury is still out on whether you can actually compliantly switch from MC to EMT without a splice, since you'd be installing conductors harvested from the MC cable inside the EMT.
You can go from Greenfield to EMT and bury that if you want to. The jury is still out on whether you can actually compliantly switch from MC to EMT without a splice, since you'd be installing conductors harvested from the MC cable inside the EMT.
Re: NM or MC to EMT change over
Here is the application.
Loft apartments in an old mill building. Some walls are metal studs and drywall and some are the original brick.
Wiring within the apartment is NM with plactic boxes. The wiring on the brick is EMT with 4" square steel boxes.
The NM is sleeved from the drywalled walls to the first box on the brick, then THHN conductors are used to continue to the other boxes on the brick.
The AHJ wants the fitting that is used to change over from NM to EMT to be exposed and not conceled in the wall. The fitting is a combo fitting, EMT setscrew and 2 screw clamp for the cable.
I have looked in the 05 code, but cannot find why he is asking for this. It's a small thing that makes him happy, but not the best looking thing. It would look much better if only the EMT came out of the wall.
I just threw in the MC. Can't you change from MC to EMT for a short distance by using a MC connector a rigid coupling and an EMT connector for the same application?
Here is the application.
Loft apartments in an old mill building. Some walls are metal studs and drywall and some are the original brick.
Wiring within the apartment is NM with plactic boxes. The wiring on the brick is EMT with 4" square steel boxes.
The NM is sleeved from the drywalled walls to the first box on the brick, then THHN conductors are used to continue to the other boxes on the brick.
The AHJ wants the fitting that is used to change over from NM to EMT to be exposed and not conceled in the wall. The fitting is a combo fitting, EMT setscrew and 2 screw clamp for the cable.
I have looked in the 05 code, but cannot find why he is asking for this. It's a small thing that makes him happy, but not the best looking thing. It would look much better if only the EMT came out of the wall.
I just threw in the MC. Can't you change from MC to EMT for a short distance by using a MC connector a rigid coupling and an EMT connector for the same application?
marinesgt0411
Senior Member
- Location
- Naples,FL 34110-9285
Re: NM or MC to EMT change over
NM to EMT has a fitting so can be buried
FLEX (greenfield) to EMT has a fitting so can be buried
MC to EMT does not have a fitting so can NOT be buried
that is my opinion so now can I get my 2 dollars so I can get my cup of coffee at 7-11
NM to EMT has a fitting so can be buried
FLEX (greenfield) to EMT has a fitting so can be buried
MC to EMT does not have a fitting so can NOT be buried
that is my opinion so now can I get my 2 dollars so I can get my cup of coffee at 7-11
marc deschenes
Senior Member
Re: NM or MC to EMT change over
Article 330
330.10 Uses Permitted (7) " in any raceway"
Article 330
330.10 Uses Permitted (7) " in any raceway"
pierre
Senior Member
- Location
- Westchester County, New York
Re: NM or MC to EMT change over
300.15(F)
300.15(F)
marc deschenes
Senior Member
Re: NM or MC to EMT change over
I'm not sure they can be buried.
Check out 300.15 (F)
I'm not sure they can be buried.
marc deschenes
Senior Member
Re: NM or MC to EMT change over
Pierre, do you see where a fitting is required when MC is used in a raceway ?
Pierre, do you see where a fitting is required when MC is used in a raceway ?
marc deschenes
Senior Member
Re: NM or MC to EMT change over
I'm confused, as some may have guessed, by the requirements of 300.15(c) and (F).
330.10 (7) allows MC to be used " in any raceway".
310.15(c) requires a fitting on the end(s) of the conduit or tubing to protect the cable from abrasion. When the raceway is used to provide physical protection
310.15(f) calls for a fitting identified for the use shall be permitted in lieu of a box or conduit body where conductors are not spliced or terminated within the fitting. The fitting shall be accessible after installation.
Does an EMT box connector with a pvc bushing meet the requirement of 310.15 (c) ?
And if exposed would it then meet the requirement of 310.15(F)
It seems to me it would.
Now if the other end of the EMT is connected to a box using a listed fitting (box conn) with a pvc bushing , I should think it would be compliant to then strip off the outer sheath of metal and make the connection required at the outlet.
Am I reading this right ??
I'm confused, as some may have guessed, by the requirements of 300.15(c) and (F).
330.10 (7) allows MC to be used " in any raceway".
310.15(c) requires a fitting on the end(s) of the conduit or tubing to protect the cable from abrasion. When the raceway is used to provide physical protection
310.15(f) calls for a fitting identified for the use shall be permitted in lieu of a box or conduit body where conductors are not spliced or terminated within the fitting. The fitting shall be accessible after installation.
Does an EMT box connector with a pvc bushing meet the requirement of 310.15 (c) ?
And if exposed would it then meet the requirement of 310.15(F)
It seems to me it would.
Now if the other end of the EMT is connected to a box using a listed fitting (box conn) with a pvc bushing , I should think it would be compliant to then strip off the outer sheath of metal and make the connection required at the outlet.
Am I reading this right ??
Re: NM or MC to EMT change over
I personally don?t see a reason this fitting needs to be accessible but here?s what the NFPA commentary states as printed in the 2005 NEC handbook.
300.15 (c)
NEC Handbook commentary:
Section 300.15(c) permits conduit or tubing to be used as support and protection against physical damage without terminating in a box. It also permits conduit or tubing to be used as physical protection for underground cables that exit from buildings or that are located outdoors on poles, without a box being required on the end of the conduit. A fitting to protect the wires or cables against physical damage is required on the ends of the conduit or tubing.
300.15(f) Fittings blah blah blah????????..The fitting shall be accessible after installation
NEC Handbook commentary:
Where a cable system makes a transition to a raceway to provide mechanical protection against damage, 300.15(f) permits the use of a fitting instead of a box. For example, where nonmetallic-sheathed cable that runs overhead on floor joists and drops down on a masonry wall to supply a receptacle needs to be protected from physical damage, a short length of raceway is installed to the outlet box. The sheath is removed for the length of the raceway. The cable is then inserted in the raceway and secured by a combination fitting that is fastened to the end of the raceway.
Seems to me that if you can transition a piece of UF to conduit for physical protection when it emerges from underground, and this fitting is buried underground you should be able to bury a NM transition in a wall or ceiling.
Bare in mind this fitting can be an EMT connector it doesn?t have to be a specialty connector.
I personally don?t see a reason this fitting needs to be accessible but here?s what the NFPA commentary states as printed in the 2005 NEC handbook.
300.15 (c)
NEC Handbook commentary:
Section 300.15(c) permits conduit or tubing to be used as support and protection against physical damage without terminating in a box. It also permits conduit or tubing to be used as physical protection for underground cables that exit from buildings or that are located outdoors on poles, without a box being required on the end of the conduit. A fitting to protect the wires or cables against physical damage is required on the ends of the conduit or tubing.
300.15(f) Fittings blah blah blah????????..The fitting shall be accessible after installation
NEC Handbook commentary:
Where a cable system makes a transition to a raceway to provide mechanical protection against damage, 300.15(f) permits the use of a fitting instead of a box. For example, where nonmetallic-sheathed cable that runs overhead on floor joists and drops down on a masonry wall to supply a receptacle needs to be protected from physical damage, a short length of raceway is installed to the outlet box. The sheath is removed for the length of the raceway. The cable is then inserted in the raceway and secured by a combination fitting that is fastened to the end of the raceway.
Seems to me that if you can transition a piece of UF to conduit for physical protection when it emerges from underground, and this fitting is buried underground you should be able to bury a NM transition in a wall or ceiling.
Bare in mind this fitting can be an EMT connector it doesn?t have to be a specialty connector.
pierre
Senior Member
- Location
- Westchester County, New York
Re: NM or MC to EMT change over
Delta
Take a look at:
300.5(H)
"(H) Bushing. A bushing, or terminal fitting, with an integral bushed opening shall be used at the end of a conduit or other raceway that terminates underground where the con-ductors or cables emerge as a direct burial wiring method.
A seal incorporating the physical protection characteristics of a bushing shall be permitted to be used in lieu of a bushing.
Basically, when making a transition from one wiring method to another without using a box, a fitting of some type will be required and it will be required to be exposed. Of course the underground method is permitted to not be exposed
Delta
Take a look at:
300.5(H)
"(H) Bushing. A bushing, or terminal fitting, with an integral bushed opening shall be used at the end of a conduit or other raceway that terminates underground where the con-ductors or cables emerge as a direct burial wiring method.
A seal incorporating the physical protection characteristics of a bushing shall be permitted to be used in lieu of a bushing.
Basically, when making a transition from one wiring method to another without using a box, a fitting of some type will be required and it will be required to be exposed. Of course the underground method is permitted to not be exposed
dana1028
Senior Member
- Location
- San Francisco Bay area
Re: NM or MC to EMT change over
This is just slightly off base.
Does a flex 90 (FMC) also need to remain accessible?
[e.g. flex 90 into the back of a box]
[ November 26, 2005, 12:15 PM: Message edited by: dana1028 ]
This is just slightly off base.
Does a flex 90 (FMC) also need to remain accessible?
[e.g. flex 90 into the back of a box]
[ November 26, 2005, 12:15 PM: Message edited by: dana1028 ]
- Location
- Massachusetts
Re: NM or MC to EMT change over
marinesgt0411
Senior Member
- Location
- Naples,FL 34110-9285
Re: NM or MC to EMT change over
OK been proved wrong again but that is why I read this forum to learn
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