Usage of EMT on outdoor applications

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michael a noakes

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Can EMT be used outside / slab as a raceway? I did look in the code book and maybe I just have an old book.....but it stated that if it is not in a conjested work area or in physical damage it can be used. Down here in the South due to the climatic conditions it would be corrosive. Would this not be physical damage? Not trying to sound as though I don't understand would just truly appreciate some help.

Thank you in advance...:-?
MAN Electric
 
if you dont paint it, it will rust like no other. every piece of EMT i seen outside that hasnt been painted looks terrible. PVC is best to use in a slab.

you could run PVC in the slab and when you poke up through the floor you could change over to EMT or RMC using your choice of female adapters, male adapters and rigid couplings. thats the way i do it and never had an issue. if you choose to use a male adapter and a rigid coupling just make sure the coupling is in the cement or the male adapter might get broken at the area where the threads meet the part where the pipe goes in
 
emt running on finshed slab

emt running on finshed slab

were in code book that allows emt to be run outside on a slab unpreteceted by weather or as a service stem for a meter:confused:
 
michael a noakes said:
were in code book that allows emt to be run outside on a slab unpreteceted by weather or as a service stem for a meter:confused:
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Read art. 358.10.

358.10 Uses Permitted.
(A) Exposed and Concealed. The use of EMT shall be permitted for both exposed and concealed work.
(B) Corrosion Protection. Ferrous or nonferrous EMT, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and judged suitable for the condition.
(C) Wet Locations. All supports, bolts, straps, screws, and so forth shall be of corrosion-resistant materials or protected against corrosion by corrosion-resistant materials.
FPN: See 300.6 for protection against corrosion.
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The code does not forbid emt as a service riser thus it is allowed. It cannot however penetrate the roof and be used as a mast since it is not approved for use as a service mast.

230.28 Service Masts as Supports.
Where a service mast is used for the support of service-drop conductors, it shall be of adequate strength or be supported by braces or guys to withstand safely the strain imposed by the service drop. Where raceway-type service masts are used, all raceway fittings shall be identified for use with service masts. Only power service-drop conductors shall be permitted to be attached to a service mast.
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stickboy1375 said:
The question is, where does it not...
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Here.

358.12 Uses Not Permitted.
(2)Where protected from corrosion solely by enamel.
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Where is it permitted?

358.10 Uses Permitted.
(B) Corrosion Protection. Ferrous or nonferrous EMT, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by corrosion protection and judged suitable for the condition.
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What is acceptable corrosion protection? Bitumastic? If you live in California that stuff will give you a wicked case of cancer!
 
358.12 Uses Not Permitted.
(2)Where protected from corrosion solely by enamel.

So I go out to the local electrical supplier and pick up a bundle of EMT. . What's the chance that the manufacturer has added a protection other than enamel ?

Does the installer have to add a coating or is it commonly already treated as needed to be used in wet apps/outside ?
 
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