Flooring guys... (and an electrician) ...a question

[Ron]

To explain the romex and conduit question,
When running conduit you have to figure the fill factor of the conduit, It all depends on cable size and amps. The cables must have area in order to keep from over heating. Romex doesn't allow you to figure it due the caseing, The figuring is done by single conductors. Running open ended conduit over romex is ok, Just don't have it in a closed raceway. IE box to box conduit.

Mike,
You know I know my fill calculations, etc.
There is a different temp rise calc for multi conductor cables, but I still can not findd a no-no...even had lunch with a county inspector today and asked him and he said so long as the fill rates are observed there is no issue....So I dunno.

Passed my EC test in 01 and have done CEs sinc eso maybe I am rusty, but....

 

[RatLabGuy]

Crazy is Box Fill Figuring.

Here ya go

So, I understand that you only want to fill the conduit to a certain extent, that makes perfect sense.
But saying "B/c it's in Romex, we can't figure out the fill - and therefore since we can't figure it out, you just shouldn't do it." - that's crazy.
What if you put that Romex into a 6" conduit?
It's not like it's impossible to calculate the area inside a Romex sleeve, it's just not a circle.

 

[burrellsjeep]

Just what I have been told,

Rat Lab I agree with you. I am just not aware of an adjustment for the jacketing on the romex. Not saying that there isn't one.

Passed my EC test in 05.

 

[burrellsjeep]

Found this

National Electrical Code disallows the running of Romex or similar, multiconductor wire through any type of conduit or wire chase in most cases. Although there are a few exceptions, there is a very good reason for only allowing individual wires in conduit, raceways, wiretrays, etc. That reason is heat. The biggest reason for the Code is fire prevention, although protection against shock or electrocution is also extremely important, of course. Wires crowded together heat up more than separate wires under the same circumstances. Romex usually contains wires with insulation individually rated for up to 75 degrees Celsius, but when in Romex, the wires are de-rated to only 60 degrees Celsius because the outer sheath holds them together so closely. If Romex were allowed in conduit, etc., then the wire would have to be rated at an even lower temperature, but 60 degrees is the minimum allowed. Higher temperatures also increase wire resistance, making it less efficient. This all basically means that you should plan on running individual wires in your vertical wire chase(s) instead of Romex or any other multiconductor cable.

 

[Ron]

How many homes have we seen violate this one.....4" conduit ran to the crawl and the attic from the panel...

 

[burrellsjeep]

Oh my house is one that comes to mind.

One piece of 3'' PVC that stubs above the ceiling in the garage from the main breaker panel, With all the Romex home runs in the house running through it. It was built in 2005, passed code.

 

[GotWood]

Cutting a rectangle out of the laminate and screwing the cabinet to the subfloor is probably the best and fastest way. If there's a possibility that you might move or remove the island later, hang on to enough attic stock of the laminate to repair the hole.

Have you ever tried to repair a laminate floor? Didn't think so.



This may be my favorite thread of all time. You guys can weld up a transfer case in the woods with 2 car batteries, a couple sets of jumper cables and a clothes hanger but know nothing about floors.



Ok, I know I'm making a big deal, but I finally feel like the resident expert

 

[doc]

The local inspector also teaches the code classes & he was the one discussing moisture saturation, etc......who knows. I passed in '98 & have seen many romex/conduit runs.....the rule included to use less than 2-3' of conduit - but I'm very rusty on residential.

 

[burrellsjeep]

The local inspector also teaches the code classes & he was the one discussing moisture saturation, etc......who knows. I passed in '98 & have seen many romex/conduit runs.....the rule included to use less than 2-3' of conduit - but I'm very rusty on residential.

I do recall that the length of the conduit can be less than a set number and be allowed, for stub ups. I believe the use of conduit to add protection to the romex is allowed, but not as the means of running the romex.

So all in all the stub down for the island should be allowed by code as long as it is less than 2 foot or so.

 

[shawn]

To explain the romex and conduit question,
When running conduit you have to figure the fill factor of the conduit, It all depends on cable size and amps. The cables must have area in order to keep from over heating. Romex doesn't allow you to figure it due the caseing, The figuring is done by single conductors. Running open ended conduit over romex is ok, Just don't have it in a closed raceway. IE box to box conduit.

Right. Romex isn't listed for use in "conduit systems", but you can use conduit to protect a romex wire from damage. The rule I've been told is that if you have a junction, switch, receptacle, etc attached to the conduit, that's crossing the line into a conduit system. The problem is that the NEC isn't very specific about the grey area in the middle, so it's up to the inspector's interpretation. That's why you have some jurisdictions that ban it outright, some that don't care, and others where the interpretation varies from inspector to inspector.