MC Cable

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Mike115

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I have a question about installing some mc cable ,12 gauge,in a very wet location in a papermill at the wet end. We have been having a discussion as whether we should bring 5 cables up from the basement through the floor in a very wet location or bring those same cables from another route from above and to the motors they are going to. The voltage is 575. My concern is of course over time will it become a safety and liabilty concern if we go through the floor. The engineer in charge wants to save some money. Is there code saying one way or the other and if not would someone offer advice? :)
 

pismo

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Pismo Beach
Mike115 said:
I have a question about installing some mc cable ,12 gauge,in a very wet location in a papermill at the wet end. We have been having a discussion as whether we should bring 5 cables up from the basement through the floor in a very wet location or bring those same cables from another route from above and to the motors they are going to. The voltage is 575. My concern is of course over time will it become a safety and liabilty concern if we go through the floor. The engineer in charge wants to save some money. Is there code saying one way or the other and if not would someone offer advice? :)
Does the floor have more than a 2 hour fire rating? I believe MC cable is listed for 2 hour through penetrations. If it's subject to physical then I would consider providing physical protection.
 

discostu

Banned
pismo said:
Does the floor have more than a 2 hour fire rating? I believe MC cable is listed for 2 hour through penetrations. If it's subject to physical then I would consider providing physical protection.
Provide a sleeve for the protection?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I think the main issue is whether this is an appropriate use for MC? I don't think what is being suggested is specifically forbidden, but it seems to me that by the time you core the floor for 5 chunks of MC you are going to spend some money. Might as well put in EMT, especially in such a small size.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Might as well put in EMT
I wouldn't expect EMT to last very long in this application..."a very wet location in a papermill at the wet end". Maybe PVC coated rigid, but not EMT.
Don
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
don_resqcapt19 said:
I wouldn't expect EMT to last very long in this application..."a very wet location in a papermill at the wet end". Maybe PVC coated rigid, but not EMT.
Don

I completely missed the paper mill part.

Don is right. Use PVC or PVC coated. Nothing else will hold up to the corrosive environment.
 

Rockyd

Senior Member
Location
Nevada
Occupation
Retired after 40 years as an electrician.
Mike,

Assuming these cables to be coming out of a cable tray onto strut? I'm thinking that you want to have a drip loop to prevent water from entering the terminal housing(s) at the motors. In routing, consider 330.24 & 330.30(B) rule. You may want to bump up to #10. Also assuming your using Okonite (http://www.okonite.com/engineering/index.html) cable and Appleton fittings (see http://www.appletonelec.com/pdf/I 26thru27[2].pdf) for a 1/2" or 3/4" fitting.

Have had good luck in oilfield with the above set-ups in Alaska, with regard to pull-out and endurance to environment.

That is my $.02 for the problem at hand.
 
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