MC Cable Art. 330

[Ben Trueblood]

In looking at this code I am trying to determine if installing MC cable is rated to be installed inside a structure that has not been completly "dried' in. The way I read the code it appears it is rated for at least damp locations. Can anybody comment on their experience with this?


Thanks

 

[raider1]

My opinion is that if the area is a dry location when the building is complete it is a dry location during construction even if the building is not dried in.

Here is the definition of dry location:

"Location, Dry. A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction."

I know some jurisdictions will not allow cables such as NM or MC to be installed in a building unless the building is totally dried in.

Chris

 

[charlie]

110.11 Deteriorating Agents.

(2nd paragraph)
Equipment not identified for outdoor use and equipment identified only for indoor use, such as ?dry locations,? ?indoor use only,? ?damp locations,? or enclosure Types 1, 2, 5, 12, 12K, and/or 13, shall be protected against permanent damage from the weather during building construction.

 

[haskindm]

Can anyone explain the difference between damage and permanent damage? This reminds of the section that requires a "thoroughly good" connection. Once you have a "good connection" how does one go about making it "thoroughly good"? If something is not permanently damaged, is it damaged at all?
Sometimes I wonder...

 

[charlie]

Can anyone explain the difference between damage and permanent damage?

This is open for interpretation by the AHJ. However, some discoloration could be considered damaged and could be cleaned and painted to restore the item. The same item that has become brittle would be permanently damaged. Cleaning and painting would no longer repair the item.

In the case of cable that is to be kept dry, moisture that has wicked into the cable would be permanent damage.

 

[nakulak]

330.10 A 11 C (2005)

This one really gets me irritated. It clearly says that if the conductors are rated for a wet location, that the mc is rated for a wet location ("if any of the conditions are met") (look at your conductors, most mc I use is thhn/thwn)

Yet I work in several locations where they do not allow the mc to be run when under construction. What is up with that ?

 

[charlie]

What is up with that?

What is up with that?

. . . conductors are rated for a wet location, that the mc is rated for a wet location . . . What is up with that ?

Perhaps the MC cable does not have a corrosion-resistant jacket is provided over the metallic sheath. :-?