Can romex condcutors be installed in emt?

[LEO2854]

Yes, I cant run two pipes. Here is the dilemna (sort of). The ceiling is old horsehair plaster and lathe. There is a carrier beam going right to left. There is fire blocking (bricks) in between the floor joists on top of the carrier beam. The 'easiest' way would have been to run pipe and thhn. However, there are 6 dedciated circuits. 5 of them are 12/2. One is 14/2. I installed the 12/2 for a/c units to be plugged in.
If I use pipe, I will need 3 runs. Two for the 12/2 and 1 for the 14/2. Either way, it's a pain in the butt.

Yes i think that you will it will save a lott of time running the pipes

 

[hurk27]

WHAT is an MWBC? THHN has to be derated also so what is the point of using it in this situation?

because neutrals don't count as current carrying conductors when derating, also do you know that when derating you use the 90? column which with only 6 conductors will keep then at the same amperage look at Table 310.15(B)(2)(a) for 6 conductors, the adjustment is 80%

so for 14awg table 310.16 90? column is 25 amps which we derate 80% = 20 amps but because we still have to protect it at 15 it still can

and for 12 awg the table has 30 amp we can derate from.

so basically you can put all those conductors in one 1/2" conduit and still keep them supplied by the same size breakers

 

[Dennis Alwon]

If you can run pipe then it seems you could just as easily fish the wires but I am sure I am missing something.

 

[suemarkp]

Another solution -- run a feeder up that conduit and put a panel somewhere to land all those 12-2 and 14-2 circuits. The attic is not an ideal location for a panel though. But maybe once the wire is up there you can come down to a panel in some other location.

The problem with a multiwire branch circuit solution will be AFCI protection (you didn't mention if dwelling or not). If these outlets end up in bedrooms, or other rooms that require AFCI's, two pole AFCI's are not easy to find and are impossible for some panels.

If you could possibly run a new conduit, you could probably fish the NM cable up that pathway easier than pushing a stick of conduit.

 

[PaulWDent]

Many circuits in same conduit issue

Many circuits in same conduit issue

I have to do a similar thing: Run many circuits from an attic down conduit to a panel on a lower floor. I am thinking of letting the circuits share a common neutral and ground down the conduit, and putting a junction box in the attic containing a neutral bus and ground bus to split them apart again. As far as I understand, the common neutral, even if a fatter AWG, would only count as one CCC in the derating table, wouldn't it?

 

[infinity]

I have to do a similar thing: Run many circuits from an attic down conduit to a panel on a lower floor. I am thinking of letting the circuits share a common neutral and ground down the conduit, and putting a junction box in the attic containing a neutral bus and ground bus to split them apart again. As far as I understand, the common neutral, even if a fatter AWG, would only count as one CCC in the derating table, wouldn't it?

There has been much debate here about using one large neutral as you've described and still being code legal. Many feel that it isn't. This will be clarified in the 2011 NEC where the illegality of this type of installation will be spelled out in the code language.

 

[goldstar]

see next post

 

[goldstar]

Not trying to split hairs here over a small technicallity but, an RX "cable assembly" has the size and rating information imprinted on or embedded in the jacket. It will state something like "E18679 (UL) ROMEX (tm) SIMPULL AWG 14 CO 2 CDR WITH AWG 14 GROUND TYPE NM-B 600 VOLTS".

Why am I bringing this up ? Because once you strip off the jacket and install those conductors inside the conduit, those conductors have no markings on them. Now, while we all know that they are probably THWN, the fact that there are no markings will give an inspector every right to fail an inspection. I believe a better choice would be to install JB's and run stranded THHN conductors and make splices to the RX cable.

BTW, when installing RX directly into EMT you will need this type fitting :http://www.bptfittings.com/Catalog/CatalogFamily.aspx?CategoryId=33&FamilyId=381 . The EMT will also have to be grounded at some point so, I'm assuming that you'll be terminating it at the breaker panel in which case the lock-nut and set screw fittings will accomplish this. If you had planned on just using the EMT as a sleeve and not terminating it at either end then you will have to find some way to ground the EMT.

 

[cpal]

I have 5 circuits, 4 of which are 12/2, and one is 14/2. The circuits go from the attic, down a pipe chase, to the basement, which has a finished ceiling. I want to install the romex (after stripping the sheathing off) in 3/4 emt, and run it back to the panel.

312.5 (C) Cables. Where cable is used, each cable shall be secured to the cabinet, cutout box, or meter socket enclosure.

Exception: Cables with entirely nonmetallic sheaths shall be permitted to enter the top of a surface-mounted enclosure through one or more nonflexible raceways not less than 450 mm (18 in.) and not more than 3.0 m (10 ft) in length, provided all of the following conditions are met:
(a) Each cable is fastened within 300 mm (12 in.), measured along the sheath, of the outer end of the raceway.
(b) The raceway extends directly above the enclosure and does not penetrate a structural ceiling.
(c) A fitting is provided on each end of the raceway to protect the cable(s) from abrasion and the fittings remain accessible after installation.
(d) The raceway is sealed or plugged at the outer end using approved means so as to prevent access to the enclosure through the raceway.
(e) The cable sheath is continuous through the raceway and extends into the enclosure beyond the fitting not less than 6 mm (1/4 in.).
(f) The raceway is fastened at its outer end and at other points in accordance with the applicable article.
(g) Where installed as conduit or tubing, the allowable cable fill does not exceed that permitted for complete conduit or tubing systems by Table 1 of Chapter 9 of this Code and all applicable notes thereto.

There was also a discussion regarding removing the sheathing and routing NM in a raceway. The opinion was that no one was sure what the conductors were listed for. The individual conductors in NM are 90 degrees but are they thhn or thw?? the cable is listed as an assembly and there fore the installation the OP is considering may be a violation of 110.3 (B).

Just a thought!!

 

[mtfallsmikey]

Good discussion, dumb question coming...

Good discussion, dumb question coming...

Another solution -- run a feeder up that conduit and put a panel somewhere to land all those 12-2 and 14-2 circuits. The attic is not an ideal location for a panel though. But maybe once the wire is up there you can come down to a panel in some other location.

The problem with a multiwire branch circuit solution will be AFCI protection (you didn't mention if dwelling or not). If these outlets end up in bedrooms, or other rooms that require AFCI's, two pole AFCI's are not easy to find and are impossible for some panels.

If you could possibly run a new conduit, you could probably fish the NM cable up that pathway easier than pushing a stick of conduit.

As far as mounting a panel in the attic is concerned....if it would have to be done, should an outdoor rated panel be used? This is a dilemna I may be facing when I rewire the second floor of The Wife's house, and remove the K & T....

 

[roger]

Not trying to split hairs here over a small technicallity but, an RX "cable assembly" has the size and rating information imprinted on or embedded in the jacket. It will state something like "E18679 (UL) ROMEX (tm) SIMPULL AWG 14 CO 2 CDR WITH AWG 14 GROUND TYPE NM-B 600 VOLTS".

Why am I bringing this up ? Because once you strip off the jacket and install those conductors inside the conduit, those conductors have no markings on them. Now, while we all know that they are probably THWN, the fact that there are no markings will give an inspector every right to fail an inspection.

This is true and is covered in 310.11, see post #15

 

[roger]

As far as mounting a panel in the attic is concerned....if it would have to be done, should an outdoor rated panel be used?

No, unless there are some serious roofing problems (leaks)

Roger

 

[LarryFine]

This is a dilemna I may be facing when I rewire the second floor of The Wife's house, and remove the K & T....

Sounds like an interesting divorce settlement.

 

[goldstar]

This is true and is covered in 310.11, see post #15

Thanks Roger. Missed that somehow. Getting old I guess

 

[roger]

Getting old I guess

That makes both of us.

Roger

 

[petersonra]

I have occassionally wondered why some enterprising NM manufacturer does not put THWN conductors labeled as such inside the sheath so that the sheath could be removed and the conductors used for finishing runs going outside.

 

[cpal]

As far as mounting a panel in the attic is concerned....if it would have to be done, should an outdoor rated panel be used? This is a dilemna I may be facing when I rewire the second floor of The Wife's house, and remove the K & T....

How hot does the attic get??

 

[Dennis Alwon]

How hot does the attic get??

We have gone thru this scenario before and it seems that the ambient temp for the breaker is not an issue.

 

[Twoskinsoneman]

I have occassionally wondered why some enterprising NM manufacturer does not put THWN conductors labeled as such inside the sheath so that the sheath could be removed and the conductors used for finishing runs going outside.

Competition is rough. If you want to sell 250' of 14/3 for $70 ur gonna do it cheap! which means no printing on individual wires. It isn't required...

 

[earlejohnson]

Not trying to split hairs here over a small technicallity but, an RX "cable assembly" has the size and rating information imprinted on or embedded in the jacket. It will state something like "E18679 (UL) ROMEX (tm) SIMPULL AWG 14 CO 2 CDR WITH AWG 14 GROUND TYPE NM-B 600 VOLTS".

Why am I bringing this up ? Because once you strip off the jacket and install those conductors inside the conduit, those conductors have no markings on them. Now, while we all know that they are probably THWN, the fact that there are no markings will give an inspector every right to fail an inspection. I believe a better choice would be to install JB's and run stranded THHN conductors and make splices to the RX cable.

BTW, when installing RX directly into EMT you will need this type fitting :http://www.bptfittings.com/Catalog/CatalogFamily.aspx?CategoryId=33&FamilyId=381 . The EMT will also have to be grounded at some point so, I'm assuming that you'll be terminating it at the breaker panel in which case the lock-nut and set screw fittings will accomplish this. If you had planned on just using the EMT as a sleeve and not terminating it at either end then you will have to find some way to ground the EMT.

just use pvc for the sleeve then dont worry about grounding the emt