Panel wiring

[TimMiller]

I'm adding a panel to the house, and before when i have hooked up panels they used to sell a plastic grommet that would snap into the top to run all of the romex through. Now i cannot find them, and when I have glanced through the books at the hardware store they show running each piece of romex through its own separate knock out and using a cable clamp for each piece. Has there been a code change where you cannot just run all of the romex through one 2" knockout? Can i just get a 2" cable clamp and run all of the romex through there and then tighten it down?

 

[DH in Carolina]

Tim look up article 312.5 exception C in the national electrical code. You can do what you are talking about but you have to run all the wires through a piece of non flexible pvc conduit at least 18 inches long. The wires have to be stapled within 12 inches of where they enter the conduit. DH

 

[TimMiller]

I thought somewhere it was against code to run romex through conduit.

 

[buickanddeere]

Running all the cables through one 2" knockout instead of each cable having it's own L16 and knockout??? Must be one awful looking mess of a wiring job.Not allowed around here.

 

[TimMiller]

used to be quite common, not so much apparently anymore. My problem is that i need to run 15 runs of 10/3, there are not 15 knock outs on the top of the panel, and i do not have any room on the sides of the panel since it is mounted in the wall. I cannot run the wire down the wall next to the panel because there is another panel there, the other wall is a fake wall, and i would have to knock out a good section of brick to feed it through. So doing some more reading you can run romex through a piece of conduit into the box. Now if i am running the wires through 2" conduit do i still have to adhear to a 40% fill, I can derate the wire, I am using 10 awg, but its only running 20 amps.

 

[DH in Carolina]

A good electrician will make any panel look good no matter how the wires enter it. A poor electrician can make any panel look like a rats nest. DH

 

[dieselpup]

Running all into one knockout would be considered bundling unless you use the conduit as mentioned earlier. I would suggest using UL listed clamps for NM Cable (Romex). They will have a rating for how many you put through each one. You will end up with a much neater job and if you have to add or change something you won't have to fight a bundle of wires. Pick up the book Code Check Electrical. ISBN 978-1-56158-738-4 It has a lot of good information and illustrations and also references the 2002 and 05 NEC for each section.

 

[bc]

Now you have me wondering? 15 runs of 10/3 with the 10/3 having 2 hots, a neutral, and then a ground means at least a 30 breaker panel which is a large one. I'd be thinking about putting one big main panel in and eliminate anything else.

10/3 sounds like over kill to me for lighting and receptacle circuits. I personally wouldn't use anything less than 12 guage wire and 20 amp breakers but 10 guage is really hard to handle when wiring up switches, receptacles, and lights. In fact you better check your switches and receptacles cause the screws may only be rated to take 12 and 14 guage wire. Then you have to check the volume of your workboxes to see if they will handle the runs of 10/3.

I've been rewiring the barn and just replacing the 14/2wg & 15 amp breakers with 12/2wg and 20 amp breakers is a pain cause the wire is just that much stiffer to deal with and takes larger boxes to stuff wires into. I usually buy the biggest boxes anyway

I'm not even sure if 15 runs of 10/3 would fit in 2" conduit anyway. Usually the 2" hole is left for main breaker wiring coming in.

I think with 3/4" or 1" clamps you can put 2 or 3 romex runs as I understand it unless that has changed. That would get you down to a managable number of clamps although you are using 10/3 so you might have to bump up to the next knockout/clamp size.

The final say goes to your inspector/AHJ. Assuming you pulled a permit and getting an inspection, call him and ask. Around here they still grandfather in jobs done under a previous code until you do an upgrade.

 

[TimMiller]

The 10/3 is going up to junction boxes, in which it is then spit up into 4 runs of 12/2. My gf's dad designed the wiring layout, and i'm just doing what he says. I agree that 10 awg is overkill. I studied commercial electrical in school so when it comes to residential its a different animal. I'm thinking about going with a 3" piece of conduit that falls just short of the 24" derating rule. I figured out with 3" conduit i can run up to 21 runs of 10/3 without going over the 40% fill capacity. They almost doubled the size of the house, so i'm installing a 30 space sub panel which should leave enough room for expansion. I could have used the existing panel and just installed all tandem breakers and it would have fit, but he didnt go for that. Also, I kind of understand his wants to take things as overkill because the electricans apprentice wired the house, the electrician never came out to look, and he made one heck of a mess. He cut the wires back way to short, and then if you go back to pull them out, when he stripped them he dug so far down into the copper you end up breaking it off. Also there are some serious voltage drop issues from his bizzare runs. He tried to run 2 pieces of 14awg to the range (6 burner stove top) when the range clearly called for 8 awg. He made him pull that. The kitchen refridgerator, microwave (built in), all the kitchen outlets, and lights are on the same circuit. Everytime you run the microwave, you hear the breaker buzz because of the over load, and the flourescent kitchen light goes on and off every time you run anything that pulls a pretty heavy load. Also he ran 16 awg to some of the light circuits, though the OCPD for the lighting/branch circuits are 20 amps.