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Discussion Starter · #1 ·
Conduit is running from meter base, under concrete garage floor (4") to basement resi panel.
What depth does the conduit have to be?
Thanks
 

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Discussion Starter · #3 ·
Sorry, forgot to mention its in Ontario so I need to confirm that NEC is the same.
Thanks for quick reply
 

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Discussion Starter · #5 ·
I dont have my code book handy.
I looked up table 53 online and it says 600mm. Subrule 2 allows 150mm less for mech protection.
450mm or 300mm?
 

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Garage attached? If not go deep cause you will be crossing the yard with un-fused conductors.
 

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450 mm. if it is not being driven on. Under the cement slab it requires at least 50 mm. of concrete above it,these depths are to the top of the conduit so dig the trench at least 2 inches deeper for the thickness of the conduit.
 

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Rule 12-012(8)
Raceways shall be permitted to be installed directly beneath a concrete slab at grade level, provided that the concrete slab is not less than a nominal 100 mm in thickness, the location is adequately marked, and the raceway will not be subject to damage during or after installations.​
If you don't like that one then Table 53 states 450mm. The concrete slab (floor) is not considered mechanical protection because it is part of the installation; that is why para (8) is there. You could go 300mm if you add mechanical protection, then the concrete.​
Cheers​
John​
 

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Discussion Starter · #15 · (Edited)
Thanks Navyguy.I like para 8 below the concrete. With the frozen ground it will be hard enough to get it down just a few inches.
I was sceptical because an inspector recently told a contractor friend that 12" (300mm) was required under the concrete garage floor.
 

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Read carefully. I did error earlier.

1. I cannot fid where the concrete slab would not count as mechanical protection. If you can point it out I will concede to that.

2. Table 53 says 600mm under grade with vehicular traffic. This is the part I missed before.

3. 12-012(3)(c) says I can reduce by 150mm if covered by slab with minimum thickness of 50mm. This brings it down to 450mm from top of conduit to top surface of slab (floor).

If you choose to go with 12-012(8), how are you planning to mark it?
 

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If directly under slab, must be marked on top of slab. Idea of caution tape is to give room to locate tape well before damage to conduit. Can't do that if conduit is directly below slab.
 

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Discussion Starter · #19 ·
I agree with your rational but where does it state that? How is it to be marked if on the top? Paint? It should be stated somewhere.
 
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