330 type mc

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electricalist

electricalist

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dallas tx
Just need some guidance.
330.10 uses permitted (11) wet locations.-b.a jacket resistant to moisture is provided under the metal covering.
Is this the plastic sheath between the wire and outer jacket? And realistically what is a wet location you would use it in.
330.30 ( d) 2 type mc cable fittings shall be permitted as a means of cable support.
Does this mean if its accessible ,no more than 6' with a type mc fitting at both ends, its considered secured and supported?
 
electricalist said:
Just need some guidance.
330.10 uses permitted (11) wet locations.-b.a jacket resistant to moisture is provided under the metal covering.
Is this the plastic sheath between the wire and outer jacket? And realistically what is a wet location you would use it in

330.30 ( d) 2 type mc cable fittings shall be permitted as a means of cable support.
Does this mean if its accessible ,no more than 6' with a type mc fitting at both ends, its considered secured and supported?
Click to expand...

>>Yes in an accessible ceiling, no other support or securing is required
 
electricalist said:
Ty sir. What about the plastic between the outside of the mc and the wire, does that make it suitable for wet locations?
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Isn't Texas under the 2014 NEC?

(11) In wet locations where a corrosion-resistant jacket is
provided over the metallic covering and any of the
following conditions are met:

a. The metallic covering is impervious to moisture.

b. A jacket resistant to moisture is provided
under the metal covering.

c. The insulated conductors under the metallic cover-
ing are listed for use in wet locations.
Click to expand...

Compliance with highlighted is typically PVC jacketed MC.
 
electricalist said:
Thats what i thought as well. Many cities here are 2008 or 11
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The requirement wording has changed in each edition because of the ensuing confusion.

2011 330.10(A)(11)(b) says, "A moisture-impervious jacket is provided under the metal covering."

2008 says, "A lead sheath or moisture-impervious jacket is provided under the metal covering."

...but neither say anything about a corrosion-resistant outer jacket in the general requirement. That said, "standard" MC does not have a moisture-impervious jacket between armor and conductors.
 
Mr.Smart$,
When it says cable ties as means of support, they are "zip ties?"
I had an inspector says they are approved for bundling but not securing or support.
 
electricalist said:
Mr.Smart$,
When it says cable ties as means of support, they are "zip ties?"
I had an inspector says they are approved for bundling but not securing or support.
Click to expand...
There are several aliases for cable ties. Zip ties is one of them.

Using cable ties is a compliant method for both securing and supporting. Approved can only come from the AHJ [Article 100 definition and 110.2].
 
electricalist said:
Just need some guidance.
330.10 uses permitted (11) wet locations.-b.a jacket resistant to moisture is provided under the metal covering.
Is this the plastic sheath between the wire and outer jacket? And realistically what is a wet location you would use it in.
330.30 ( d) 2 type mc cable fittings shall be permitted as a means of cable support.
Does this mean if its accessible ,no more than 6' with a type mc fitting at both ends, its considered secured and supported?
Click to expand...
@electricalist - The plastic material you usually see between the conductors and the metal sheathing is part of the construction and is not making it acceptable for a wet location. The wrap is a biaxially oriented polyethylene terephthalate polyester film material that is a separator from the conductors and the sheathing and does not add any wet location properties.

Now the Type MC can be made as mentioned here (with a PVC Jacket ) or it can have that PVC jacket over the wrap as stated earlier, just under the metal sheathing. However, more than not it is applied over the metal sheathing itself in order to be used in wet locations.

And for your supporting and securing question...Yes, if it's an accessible ceiling.
 
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