[Washington1]

Can Standard MC cable be ran in a Plenum? IF so, please back it up with code, and creditable references. If not, also back it up. Please note NEC 300.22(B) as a starting place.

[Scleros]

Curious, what's wrong with what's stated in 300.22?

[Washington1]

Curious, what's wrong with what's stated in 300.22?

You tell me?

[Scleros]

I don't know for certain. I'm not an electrician, but after reading 300.22, MC without a nonmetallic outer covering (standard?) appears to be allowed in environmental plenums.

This a test question?

[stanfortyman]

All I have ever seen is typical MC cable and direct burial MC cable, so I don't know what "smooth or corrugated impervious" MC cable is.
I can only assume typical MC cable is not "impervious".

[donf]

Just to make sure we are on the same page here, It is a violation of the Fire Code to just run cable through a return air plenum. Any cable used in a return air plenum, must meet the standards released by the Fire code.

The cable being used has to meet the demands of the Fire code because if a fire were to occur and the cable starts melting, it can release some very toxic fumes into the air, which would then be carried by the plenum to other rooms or plenum openings.

And NO, I don't know the fire code reference.

[Washington1]

Just to make sure we are on the same page here, It is a violation of the Fire Code to just run cable through a return air plenum. Any cable used in a return air plenum, must meet the standards released by the Fire code.

The cable being used has to meet the demands of the Fire code because if a fire were to occur and the cable starts melting, it can release some very toxic fumes into the air, which would then be carried by the plenum to other rooms or plenum openings.

And NO, I don't know the fire code reference.

Ok, knowing this, would you say a standard MC cable can be ran in a plenum.


By the way, this is not a test question, but a question to get you thinking about MC cable. They make different types of MC cable<----knowing this should give you an insight on where I'm going with this.

[tkrussell]

What should be considered is referring to the manufacturer's datasheet to learn if the product you plan to use is listed for the application.

I attached what I believe to be one of the most popular MC cable pulled. Note is is listed for "Environmental Air-Handling Space installation".

The various types of cable made by AFC can be seen at :

AFC AC/MC Product Catalog

I also attached the datasheet for Parking Deck cable, which is coated with a PVC outer sheathing. Note that this one is not allowed in a plenum.

Note it can be installed in many other locations, such as embedded in concrete, and even certain hazardous Classified locations. This one cannot be direct buried, thou I know there are some that are allowed.

It may be helpful to know that the "Fire code" that states what raceway is allowed in plenum spaces falls under the jurisdiction of the NFPA 70 National Electric Code, Section 300.22, and NFPA being the National Fire Protection Association, and is part of the "fire code".

Not sure where you are going with this W1, but good design practice should be to first refer to the NEC to learn the allowed method, and since the NEC will be fairly generalized regarding a specific product, then refer to the manufacturer's datasheet to learn if it is listed for that application.

[Washington1]

What should be considered is referring to the manufacturer's datasheet to learn if the product you plan to use is listed for the application.

I attached what I believe to be one of the most popular MC cable pulled. Note is is listed for "Environmental Air-Handling Space installation".

The various types of cable made by AFC can be seen at :

AFC AC/MC Product Catalog

I also attached the datasheet for Parking Deck cable, which is coated with a PVC outer sheathing. Note that this one is not allowed in a plenum.

Note it can be installed in many other locations, such as embedded in concrete, and even certain hazardous Classified locations. This one cannot be direct buried, thou I know there are some that are allowed.

It may be helpful to know that the "Fire code" that states what raceway is allowed in plenum spaces falls under the jurisdiction of the NFPA 70 National Electric Code, Section 300.22, and NFPA being the National Fire Protection Association, and is part of the "fire code".

Not sure where you are going with this W1, but good design practice should be to first refer to the NEC to learn the allowed method, and since the NEC will be fairly generalized regarding a specific product, then refer to the manufacturer's datasheet to learn if it is listed for that application.

Heeeeeeeeeeey TK! Great input!
Where I'm going with this: Not all MC cable is rated for being ran in plenums. So, to just read the NEC is not enough---seeking the manufactures specifications would be a more reliable means for this install.

Thanks TK!