running 4/0 4 wire cable in 2 x4 wall

[Stevenfyeager]

If I run AL 4/0 4 wire SER horizontally in an interior 2 x 4 wall to a sub panel, the 1 1/2 inch hole just leaves 1 inch of wood on each side of the cable. With steel wire protectors on the studs, is this acceptable? Thank you.

 

[ActionDave]

300.4(D) is your reference for this.

 

[Jamesco]

If I run AL 4/0 4 wire SER horizontally in an interior 2 x 4 wall to a sub panel, the 1 1/2 inch hole just leaves 1 inch of wood on each side of the cable. With steel wire protectors on the studs, is this acceptable? Thank you.

Other factors may be at play other than 300.4(D)

Building codes. Is the 2 x 4 wall considered a load bearing wall?

Electrical safety hazard. Will the height of the horizontal feeder be such a nail(s) and or screw(s) to support shelving, or hanging a picture(s), or hanging other item(s) on the wall where the horizontal feeder may in direct contact with the backside of drywall and or outside sheathing.
If the wall is not a load bearing wall, for electrical safety, you may want to install minimum 1/16" steel plating horizontally on both sides of the 2x4 studding to protect the feeder from possible damage.



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[macmikeman]

Umm , in my state, the only time 2x4 walls are not used is for plumbing walls at the bathroom. It is done lots here. Never heard of an issue. I do however, if I have to run that stuff (I usually opt to put 2 100 main breakers at the service and run 2 separate breaker panels with 1/0 alum ser instead) I will install a pull box flush to the drywall for any 90 degree bends and splice inside , like for instance , right behind the meter/main cause you ain't gonna get no 4/0 to do a hard right turn inside a 2x4 wall space into a romex connector.

 

[JFletcher]

You can drill a hole 60% the actual width of the stud in a non load-bearing wall and 40% in a load-bearing wall. if the edge of the hole is closer than one and a quarter inch from the face of the stud, you must nail plate it.

Eta: in a load-bearing wall, the maximum hole size in a two-by-four is 1 and 3/8 inches.

you also want to nail plate both sides of the stud if possible. If you cannot get a nail plate on the outside stud, flatten the tabs and slide one in between the stud and sheathing, OSB, whatever is there to prevent siding guys from driving a nail through your Ser Cable in the future

 

[growler]

Eta: in a load-bearing wall, the maximum hole size in a two-by-four is 1 and 3/8 inches.

Can you fit 4/0 SER through a 1 3/8" hole?

Seems like you should be able to but I may be thinking of 2/0 SER. I would get a scrap piece of lumber and check it out before going any further.

 

[JFletcher]

Can you fit 4/0 SER through a 1 3/8" hole?

Seems like you should be able to but I may be thinking of 2/0 SER. I would get a scrap piece of lumber and check it out before going any further.

I think it will fit. We did an install last year we had to drill through about four exterior studs with 4/0. I do not remember the hole size we drilled.

Even though we nail plated the studs the siding guy missed a stud and ran a nail into our cable. We knew because Dominion came to install the service, they found a fault and would not hook it up.

I also remember it was a tight fit and none too fun wrestling that 4/0 in such tight quarters. I agree with you to try a scrap piece first.

 

[Jamesco]

I think it will fit. We did an install last year we had to drill through about four exterior studs with 4/0. I do not remember the hole size we drilled.

Even though we nail plated the studs the siding guy missed a stud and ran a nail into our cable. We knew because Dominion came to install the service, they found a fault and would not hook it up.

I also remember it was a tight fit and none too fun wrestling that 4/0 in such tight quarters. I agree with you to try a scrap piece first.

Even though we nail plated the studs the siding guy missed a stud and ran a nail into our cable.

Did he miss the stud or did he think he hit something solid, like maybe the head of a nail that is holding the sheathing nailed to the stud, and he just moved over and tried again? If the siding is lap siding the carpenter's options are somewhat limited where he sets the nail. Keep in mind there's a good chance the carpenter doesn't have a clue there is a feeder running through the wall studs let alone a steel plate you installed to the stud to protect the feeder.

 

[JFletcher]

Did he miss the stud or did he think he hit something solid, like maybe the head of a nail that is holding the sheathing nailed to the stud, and he just moved over and tried again? If the siding is lap siding the carpenter's options are somewhat limited where he sets the nail. Keep in mind there's a good chance the carpenter doesn't have a clue there is a feeder running through the wall studs let alone a steel plate you installed to the stud to protect the feeder.

He missed the stud by like an eighth of an inch and drove the nail through the sheathing and into the Ser cable. The nails he was using were way too long anyway they should have been 1 inch or 1 and 1/4 this one was almost 2 inches long. because the Ser cable was so stiff it didn't give when pushed against and the nail went through, and shorted the neutral to a phase.

Our cable just so happened to be against that sheathing and not dead center the wall cavity. They were installing vinyl siding and it just so happened that where they needed to nail was directly in line horizontally with our feeder.

*cue Rod Stewart's "Some Guys Have All The Luck"*

 

[ritelec]

Yes.. the siding guys...........using 2 plus +++ inch long nails........... install insulation so wires don't move much not even near a framing member........... smh..........scary stuff.

(lets not talk about kitchen cabinet installers...........)

 

[Jamesco]

He missed the stud by like an eighth of an inch and drove the nail through the sheathing and into the Ser cable. The nails he was using were way too long anyway they should have been 1 inch or 1 and 1/4 this one was almost 2 inches long. because the Ser cable was so stiff it didn't give when pushed against and the nail went through, and shorted the neutral to a phase.

Our cable just so happened to be against that sheathing and not dead center the wall cavity. They were installing vinyl siding and it just so happened that where they needed to nail was directly in line horizontally with our feeder.

*cue Rod Stewart's "Some Guys Have All The Luck"*

There is not any building code on the length of nails.

What are the odds the guy would drive the nail in the exact spot where the nail would travel through the ungrounded conductor into the neutral conductor? Had the vinyl siding nail strip been just a little higher or a lower it could have very well traveled through ungrounded conductor only. No one would have known. The nail would be Hot, energized, though.

Had a 2-1/4" or 2-1/2" wide x minimum 1/16" thick piece of steel been installed over the outside sheathing the entire length of the cable, the cable would have been protected from possible physical damage. Of course if the steel strip is where the installer needed to nail, fasten, the siding, there would be a problem for him.

It appears to me AHJs should pass a law or ordinance that does not allow a non protected Ser cable from being installed horizontally through bored holes of 2"x 4" wall studs. (Actual size of studs today are closer to 1-7/16" x 3-7/16"). I don't think it should be allowed in the vertical space between the studs space with out providing some type of physical protection from damage for the cable.