Planning Resource for Adding Wiring to Panel

[raynman1972]

Hi All,

I am getting ready to add 8-10 circuits to the established 100a subpanel that is in my 20x30 shop ahead of insulating and drywalling. Additionally, the shop has two 20a lines for a handful of outlets and a single 15a for a pair of naked bulbs all set up by the electrician when the shop and house were built.

What I am having trouble finding is a clear resource that lists what rules/considerations should be factored in when running new lines.

1. I have an 18" header directly above my panel where the three existing lines exit the panel- is there a safe number of holes that can be drilled in the header or is it just 1.25" from all edges including the same in between holes.

2. How many cables can I run through a single hole- what will comfortably fit (2-3) or is there some other kind of limit?

3. Given how many wires I will have coming out, what should I be looking at for placement, can the wires run parallel or cross at 90deg, etc.?

4. Are there good examples of numerous lines coming out of a panel and everything being routed correctly (with pictures)?

Whenever I do online searches or look through my books, all the examples I can find are always for how to add a single line while I want to coordinate more like 10 all into the same panel in what is starting to feel more and more like a tight space.

Has anybody seen a really good resource or maybe a write-up post on this site that I can study?

Thanks,
Ray

 

[AntonLargiader]

A pic or three would be tremendously helpful, as all of this depends on your actual situation. Wires per hole - you mean in an NM clamp exiting the box, or a hole in the header? Through a joist hole at least I believe officially there is no restriction but I think some inspectors bring bundling rules into play which create a problem. Both of my panels have 15 or 20 circuits coming out the top and they mostly go out the top and then fan out to each side along a joist or header, stapled in place.

When you say header I imagine a joist that's sitting on a wall, so there's no actual bending load on it. Maybe I'm imagining it wrong. Again, a pic would be great.

 

[ard]

Agree, pictures.

One clarificaton: will this be inspected? Or you just want to do it right, no inspection- just a reasonable interpretation of the code?

 

[raynman1972]

I hope the links below work right, I've never tried this before.

Regarding inspection, I can't afford 5k to have an electrician do this and my understanding is that it is really hard for an average joe to get something inspected and approved in this area. That being said, I would like this work to be done right and as compliant to code as is reasonably possible.

If the images do work, please disregard the heavy gauge cable that got roughed in a few years ago..

https://www.amazon.com/clouddrive/s...rh7c925sh0n4NURvnG?ref_=cd_ph_share_link_copy

https://www.amazon.com/clouddrive/s...TmLEakkix3dBECXlRu?ref_=cd_ph_share_link_copy

EDIT: Sorry, I can't get the pics to embed, but the links will take you to the pictures I uploaded to Amazon.

 

[ard]

Edit: images OK now.

No image

You need to edit you post, then go to 'go advanced'
Then manage attachment
Upload the pictures
You can then embed the picture in your post..or just leave as attached

If the pictures are already somewhere online, alternatively just embed the link to them using ]img[ picture location ]/img[. ( Note I've reverse the square brackets in this example).

When you see the image somewhere online, right click on it, then 'copy image link'...then paste that link in between the img tags.

 

[ard]

That is NOT an "18 inch header"

It is a double 2x4 top plate. Drill right through, 3/4" hole three wires in each. Add nail plates just in case.

What is your 'location'?

 

[raynman1972]

 

[raynman1972]

That is NOT an "18 inch header"

It is a double 2x4 top plate. Drill right through, 3/4" hole three wires in each. Add nail plates just in case.

What is your 'location'?

I am in Benton County, WA. I know the 3/4" holes should be 1.25" from the edges, does that also apply to the spacing in between each hole?

 

[matt_i]

I see what you are saying with the truss bearing right in the center of that stud cavity.

I think you are wise to not make that header a piece of swiss cheese.

What I would do is drill sideways/horizontally into the stud bay to the right, make a right turn with the wiring, and then go up into the bay where there's no truss. So essentially you put an offset in the NM wiring, a couple of feet extra per wire, minimal extra cost, problem solved.

Also will make for more comfortable working.

(could also go left if the circuits eventually route that way as well)

 

[DirtyJersey]

No, you can have the holes next to each other, it is to prevent anyone from nicking the wire when putting up drywall.
Drill in center of studs, as precaution you could hammer in nail plates to ensure wires are protected.
Only wires of the same gauge should be stapled together. So if your running 14-2 and 12-2, you cannot have both stapled together. You can run them together above or below each other and through the same holes in the joists/studs but not stapled together.

Sent from my LG-K550 using Tapatalk

 

[raynman1972]

Excellent tips, especially the right-hand-turn idea. Just so I am clear, I can run 15a and 20a wires next to, across, under, over, etc. one another as long as it is organized *and* I only staple the same gauge wires together, right? The original electrician took considerable pains with routing the cables parallel to one another and I wasn't sure if this level of organization was necessary.

Additional, question, does all of the above apply for some 220 lines? I need a 220v 20a for a mini-split HVAC, probably a 30a for an air compressor and then something for a welder and possibly even a lift. I obviously haven't planned these out yet, but just thinking ahead.

 

[DirtyJersey]

Its not necessary but is astheticly pleasing. Ideally you want to run them together along the same path and then branch off to where they go.
Staple 2 wires of same gauge ontop ea other along the path. Directly above/below staple 2 more....
I believe routing the wire is more about asthetics than code, the stapling of same gauge wire is code.

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[ard]

If you are concerned about weakening the top plate (I would not be if it was only 3,4 more holes...) you could fit a 2x6 up under the top plate, against the out sheating. It will then transfer the load down to the two 2x4s. (In the picture, imagine that 2x4 that the wires are stapled to, just slid up to the top...

This is a energy efficiency no-no (assuming that is an exterior wall) but whatever.

 

[AntonLargiader]

Only wires of the same gauge should be stapled together. So if your running 14-2 and 12-2, you cannot have both stapled together. You can run them together above or below each other and through the same holes in the joists/studs but not stapled together.

I've never read that as a requirement. What's the applicable code?

 

[DirtyJersey]

I've never read that as a requirement. What's the applicable code?

TBH, I'm not sure, it's what I've been told.
Maybe its asthetics or maybe it's the AHJ here in NJ.

Sorry for any misinformation. When we rough in, we only staple 2 wires of same gauge together.

Sent from my LG-K550 using Tapatalk

 

[AntonLargiader]

Just asking because I'll have an inspection coming up and I don't want to fail it for something like this. There is a lot of angst online about stapling and bundling, but it seems the actual requirements are pretty terse: fastened at specified intervals with non-damaging fasteners, not stapled on edge. Beyond that I think you get into staple size and corresponding manufacturer-approved cable size, but the staple-and-zip-tie method seems to circumvent all of that. And then there are all sorts of staple alternatives like straps and stackers.

I'm fastening NM-b to 85 year old oak beams, which is a challenge for staples. I'm using one-hole straps in some places which are advertised as being for 12-2 and 14-2, but fit two such cables very nicely.

334.30 Securing and Supporting. Nonmetallic-sheathed cable shall be supported and secured by staples, cable ties, straps, hangers, or similar fittings designed and installed so as not to damage the cable, at intervals not exceeding 1.4 m (41/2 ft) and within 300 mm (12 in.) of every outlet box, junction box, cabinet, or fitting. Flat cables shall not be stapled on edge...

 

[teamextreme]

The stapling of cables requirements boils down to the requirement to follow the manufacturer's listing for use. If the box says you can staple a 14-2 and a 12-2, then you can do it. There's nothing in the NEC that says you can't, you just have to follow the manufacturer's instructions.