Type uF wire

[kbsparky]

I have encountered a situation where there appears to be some concern expressed by a homeowner.

A circuit originates from the main distribution panel (actually a sub-panel) with type NM cable, then goes underneath the house in a crawl space. In this crawl space, it terminates in a junction box, and then emerges with uf cable. This wire is laid on the ground until it disappears under the foundation where it remains buried for 20 feet or so feeding an outside shed. From the outside, you can't see the wire at all.

The owner had some surround-sound folks over to install some remote speakers for their new entertainment system. While under the house installing their speaker wires, they encountered this piece of uf, and then told the owner that there was some "high voltage" lines just lying there, and that was a hazard.

I had a look at it, but do not think that is any unusual hazard per se, since type uf wire is rated for outdoor use, and lying on the ground should not pose any. Now if it were type NM cable I might have been concerned, but not uf.

Now those owners are paranoid about these "high voltage" lines being under their house.

Do you think that I should offer to fasten the lines to the underside of the house, instead of leaving them on the ground? Would that make the presence of them any less hazardous? Should I tell the homeowner that their walls are full of "high voltage" lines, and anyone cutting holes in the walls would be at risk for shorting them out, or starting a fire? :-?

How would you handle this?

 

[M. D.]

If I had to crawl into that space I would not want to have to lay on them ,.. and aren't they supposed to be supported ,.. unless it was fished in ,..I suppose

 

[kbsparky]

Lying on the ground isn't supported? It's supported the entire length ...! Yes, it appeared that it was originally fished across that crawl space, since it was kind of tight down there (less than 2 feet clearance).

 

[Dennis Alwon]

Uf cable when used as nm cable must be installed the same as NM (art. 340.10(4)

 

[Dennis Alwon]

Lying on the ground isn't supported?

Nope it isn't. Can you run nm in the attic by laying it on the floor joists without a staple? I don't think so.

 

[LarryFine]

Nope it isn't. Can you run nm in the attic by laying it on the floor joists without a staple? I don't think so.

Supported, yes; secured, no.

 

[cpal]

340.10 Uses Permitted.
Type UF cable shall be permitted as follows:
(4) Installed as nonmetallic-sheathed cable. Where so installed, the installation and conductor requirements shall comply with Parts II and III of Article 334 and shall be of the multiconductor type.

340.12 Uses Not Permitted.
Type UF cable shall not be used as follows:

(10) Where subject to physical damage

If it must be installed per 340.10(4) and if it is restricted per 340.12(10) then it needs to be elevated, and protected.

 

[Twoskinsoneman]

Uf cable when used as nm cable must be installed the same as NM (art. 340.10(4)

What exactly does this mean? How do you know when you are using UF as a substitue for NM? If you are using it ANYWHERE you are also allowed to use NM does this mean you are autoatically using it as a substitute for NM?

 

[Twoskinsoneman]

Lying on the ground isn't supported? It's supported the entire length ...! Yes, it appeared that it was originally fished across that crawl space, since it was kind of tight down there (less than 2 feet clearance).

I believe yes it is supported. Just like run through holes in wood framing members....supported.

 

[vinster888]

typical data guys think 50v is high voltage. what a bunch of maroons. i run across them all the time.

 

[SAC]

Nope it isn't. Can you run nm in the attic by laying it on the floor joists without a staple? I don't think so.

Apparently those that wired my house think so - its a mess up there!

 

[kbsparky]

Uf cable when used as nm cable must be installed the same as NM (art. 340.10(4)

The point here is the UF was used instead of NM, since the person who originally installed it knew that NM would not be suitable lying on the ground. It stands to reason that is why the junction box was used to change the wiring method, since it ultimately ended up being buried in a trench to the shed.

 

[Dennis Alwon]

What exactly does this mean? How do you know when you are using UF as a substitue for NM? If you are using it ANYWHERE you are also allowed to use NM does this mean you are autoatically using it as a substitute for NM?

I believe you have answered your own question. IMO, uf must be installed as nm cable would be installed in any location NM would be allowed to be used. Basically it is nm cable with an added feature of being used underground or as an aerial cable, etc. In situations other than those it must be secured and supported

334.30 Securing and Supporting.
Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (4? ft) and within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting. Flat cables shall not be stapled on edge.
Sections of cable protected from physical damage by raceway shall not be required to be secured within the raceway.

 

[Dennis Alwon]

The point here is the UF was used instead of NM, since the person who originally installed it knew that NM would not be suitable lying on the ground. It stands to reason that is why the junction box was used to change the wiring method, since it ultimately ended up being buried in a trench to the shed.

Rationalize it as much as you want to but IMO, you are dead wrong. UF is not allowed to lay on the ground either inside or outside.

 

[PetrosA]

Rationalize it as much as you want to but IMO, you are dead wrong. UF is not allowed to lay on the ground either inside or outside.

So a wire that is rated for direct burial can't be in contact with earth? IMHO, a dirt crawlspace with 2' clearance between bottom of joist and dirt is not an environment where I would consider a UF subject to damage since there would have to be an extreme need to even venture into it. A 6" flex duct would make it completely impassable to any adult. Aside from the danger of encountering something nasty like a Fiddleback, poisonous snake or rabid rodent, stapling the UF or drilling the joists is going to be next to impossible in that space, and I would say that UF is just the thing for those conditions.

 

[Twoskinsoneman]

Rationalize it as much as you want to but IMO, you are dead wrong. UF is not allowed to lay on the ground either inside or outside.

Just for funzees would it be okay to staple the cable to the ground?
BTW the whole you are dead wrong thing is a little strong for a very debateable issue....

 

[Twoskinsoneman]

So a wire that is rated for direct burial can't be in contact with earth? IMHO, a dirt crawlspace with 2' clearance between bottom of joist and dirt is not an environment where I would consider a UF subject to damage since there would have to be an extreme need to even venture into it. A 6" flex duct would make it completely impassable to any adult. Aside from the danger of encountering something nasty like a Fiddleback, poisonous snake or rabid rodent, stapling the UF or drilling the joists is going to be next to impossible in that space, and I would say that UF is just the thing for those conditions.

Well you would be (giggle) dead wrong! Get your sorry butt under there and staple that UF!!

 

[PetrosA]

Well you would be (giggle) dead wrong! Get your sorry butt under there and staple that UF!!

Ok, but I'll have a rope tied to my feet and you WILL be there to pull me out

Seriously, two-foot clearance aside - If there were no sufficient access to the space without knocking out brick or stone foundation (this happens in some 19th century buildings) would you bust out an entrance just so you could get in there to staple?

 

[Pierre C Belarge]

So a wire that is rated for direct burial can't be in contact with earth? IMHO, a dirt crawlspace with 2' clearance between bottom of joist and dirt is not an environment where I would consider a UF subject to damage since there would have to be an extreme need to even venture into it. A 6" flex duct would make it completely impassable to any adult. Aside from the danger of encountering something nasty like a Fiddleback, poisonous snake or rabid rodent, stapling the UF or drilling the joists is going to be next to impossible in that space, and I would say that UF is just the thing for those conditions.

I agree with the premise that the cable installed in a 2 foot crawl space is most likely not subject to physical damage.
Here is what I see as another example of people saying it is not good based on there personal preference.
I am too tired at the moment to look in the NEC, but maybe tomorrow I will look to see if there is a section that would really restrict this type of installation.

 

[M. D.]

I guess those speaker guys were skinny and never head of fishing ???