I have seen this article posted a few times, but not with the question that I am presenting.
The question pertains to article 517.30, specifically “mechanical protection” for essential systems. I am currently doing an underground “beneath slab” for an OSED. The engineer has this article cited in his specs for “beneath grade”.
He is requesting for essential systems to be in schedule 80 or concrete encased schedule 40 underneath the slab.
Which having a concrete encased duct bank beneath slab for branch circuits has not been typical in my career.
The branch circuits mentioned are not feeding patient care areas and are not located outside the slab. I do not see how this article will apply to conduits underneath the slab.
The points that I am having difficulty understanding are as follows;
1.) There is no definition for “mechanically protected” in the NEC, whether it's article 100 or listed in 517, unless there was something I overlooked. And if it is not listed, a change should be made to clarify in future versions of the NEC.
2.) When looking into the definition of “mechanically protected” via google, it states, “Mechanically protected refers to equipment wiring, or components enclosed, shielded, or positioned to prevent damage from external forces like physical impact, abrasion, vibration or tampering….”
3.) How are conduits underneath the slab not “mechanically protected” from elements listed above such as “physical impact, abrasion, vibration or tampering”?
4.) How does this code apply to anything outside of above slab work or possibly outside the building.
Please help with my understanding of what the engineer is seeing and my further knowledge or if this is something that we should possibly look further to in the future. Thank you.
The question pertains to article 517.30, specifically “mechanical protection” for essential systems. I am currently doing an underground “beneath slab” for an OSED. The engineer has this article cited in his specs for “beneath grade”.
He is requesting for essential systems to be in schedule 80 or concrete encased schedule 40 underneath the slab.
Which having a concrete encased duct bank beneath slab for branch circuits has not been typical in my career.
The branch circuits mentioned are not feeding patient care areas and are not located outside the slab. I do not see how this article will apply to conduits underneath the slab.
The points that I am having difficulty understanding are as follows;
1.) There is no definition for “mechanically protected” in the NEC, whether it's article 100 or listed in 517, unless there was something I overlooked. And if it is not listed, a change should be made to clarify in future versions of the NEC.
2.) When looking into the definition of “mechanically protected” via google, it states, “Mechanically protected refers to equipment wiring, or components enclosed, shielded, or positioned to prevent damage from external forces like physical impact, abrasion, vibration or tampering….”
3.) How are conduits underneath the slab not “mechanically protected” from elements listed above such as “physical impact, abrasion, vibration or tampering”?
4.) How does this code apply to anything outside of above slab work or possibly outside the building.
Please help with my understanding of what the engineer is seeing and my further knowledge or if this is something that we should possibly look further to in the future. Thank you.
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