Flex Metal Conduit in Drywall-Gypsum Wall

[vidividi12]

Hi,

I know that flexible metal conduit can be used for connection to lighting fixtures and vibrating motors. However, I want to use flexible metal conduit for device(receptacle-switch) boxes in drywall instead of EMT. Is there any restrictive item in NEC? I found that FMC is permitted to be used in exposed and concealed locations(348.10) but I want to be sure. Can I use FMC in drywall instead of EMT?

 

[roger]

Yes, generally speaking it can be used where EMT is used. Article 517 has some restrictions though.

Roger

 

[powerpete69]

348.12 lists the places you can not use it. I think you are good to go assuming you are not pouring gasoline, oil or venting explosive gases down your wall.

Skimmed thru the rest of section 348, looks like you will be installing FMC for your receptacle-switch boxes. Looks like you can use it in your ceiling as well for light fixtures and what not. Feel free to use on your basement cinder walls as well assuming they are not wet.

 

[vidividi12]

Dear All,

Thank you very much.

 

[infinity]

A few restrictions on FMC if longer than 6' is cannot be used as an EGC. Also if longer than 6' it cannot be 3/8".

 

[vidividi12]

A few restrictions on FMC if longer than 6' is cannot be used as an EGC. Also if longer than 6' it cannot be 3/8".

I will take into consideration this subject, thank you.

 

[texie]

I will take into consideration this subject, thank you.

Look carefully at 250.118(5). Note that the 6' restriction is the total combined length-not just each section.

 

[augie47]

Note also 348.42.. no concealed angle connectors.

 

[vidividi12]

I will check again. Thank you very much.

 

[vidividi12]

Is there any restrictions for FMC using in fire-rated wall? We have 15-min fire rated wall.

 

[roger]

You will need to seal the membrane penetration with a proper assembly, 3M, Rectorseal, Hilti, and other manufacturers have online help with their products.

Roger