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10/3 Romex through studs

460Rustang

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Joined
Oct 9, 2013
Messages
208
Location
Nawlins
10/3 Romex through studs,.....

Is there a code / safety limit of how many strands of 10/3 Romex can go through one drilled hole through a stud.

Is three strands run through one hole drilled through a stud OK?
 
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Labradorian

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Joined
Nov 5, 2013
Messages
315
Location
Pembroke, ON
10/3 Romex through studs,.....

Is there a code / safety limit of how many strands of 10/3 Romex can go through one drilled hole through a stud.

Is three strands run through one hole drilled through a stud OK?

According to the Canadian Electrical Code, which is almost identical to the NEC, Rule 4-004(12) The rule says that where cables are in contact with each other for distances exceeding 60cm(24") ampacity of the conductors must be corrected by applying the factors of table 5C
1-3 conductors may carry 100% load
4-6 conductors may carry 80% load

The fact that cables carrying general lighting and plug outlets have always been derated to 80% by Rule 12-004 ande table 5C permits 6 conductors bundled together with this 20% ruduction in current carrying capacity.

THEREFORE cables supplying these outlets maybe bundled as follows:

Three 2 conductor cables may be run in contact without further derate OR
Two 3-conductor cables may be run in contact without further derate.

All other cables should be run in separate holes to ensure separation.
The bare bonding wire is not counted in this application.

I know the above might be a waste of time telling you but this only applies if the cables are bundled together for more than 24"

this means that you could have many cables running through a hole in a stud without derating provided that the cables fan out in different directions so that are not in physical contact for more than 24" at any one point.
 
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nehog

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Joined
Jan 2, 2010
Messages
7,935
Location
Jaffrey, NH
I think the issue is the maximum size hole you drill in the stud. The hole should not exceed 40% of the stud's depth (so a 2x4, which is 3.5" deep, is 1.4" diameter.) I typically drill a 7/8" hole for wires, and when I have more wires than will fit, I drill another hole up a few inches.
 
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