Subpanel and wiring questions

[Slickdonkey]

I have two quick questions I hope someone can answer:

1) I'm adding a subpanel that is rated at 125A. I'm only going to install 90A worth of breakers for the time being. Can I use a 125A breaker in the main panel for the subpanel feed, or should I only use a breaker rated for the current amount of circuits in the subpanel (90A or 100A breaker in this case)

2) I am adding a few new circuits to said subpanel. I ran all the wire (14/2, about 75 feet), but my spool ran out and I came up about 15 feet short. Can I just solder some more 14/2 wire onto the end of it and cover it up with electrical tape? Or do I need to enclose the wire in a junction box and use wire nuts? This is in the crawlspace, if it matters.

Thank you!

[Slickdonkey]

Two other questions:

3) What gauge wire should I use to run between the main panel and the subpanel? I'm thinking either 1/3 or 2/3 copper. The panels will be right next to eachother with one stud in between.

4) Do I need to run this cable in conduit?

[HayZee518]

A 125a panel is just the mains rating you can use any value breaker to feed it up to 125 amp.
A sub panel is a sub panel is a sub panel. Whether it be a foot away or a hundred feet away it is still a sub panel and needs that aux ground bar.
You feed it with 1-4 romex copper for 90 amp or 100 amp. 2/4 aluminum can also be used.
You don't have to use conduit if you want. Romex can be used if you staple it along a surface or snake it in a wall.
You're gonna have to purchase more 14/2 to finish your run so why not buy enough to make the run without a splice. Use the short piece for something else.
Besides any splice or junction box needs to be exposed or accessible with a blank cover.

[Slickdonkey]

If I were to wire the subpanel for 125A from the start, what size Romex should I use? This would avoid having to rewire later if I add another circuit to bring the subpanel over 90A.

As for the cable run, the reason I wanted to splice is that the cable is already snaked through walls and stapled. It will be a real pain in the butt to tear it all up and do it over again. I think I'll use a junction box like you suggested.

Thanks for your help!

[mrcaptainbob]

Hayzee, you mentioned that a splice needs to be in a junction box that's exposed or accessible. While doing some work in this ol' house I found a couple junction boxes inside the wall as well as one in the ceiling. THese would be 'accessible' if a hole were cut in the drywall to get to them...should the need arise. Would that have been an incorrect installation? I haven't approached the re/wiring portion of this project yet.

[Snoonyb]

1) I'm adding a subpanel that is rated at 125A. I'm only going to install 90A worth of breakers for the time being. Can I use a 125A breaker in the main panel for the subpanel feed, or should I only use a breaker rated for the current amount of circuits in the subpanel (90A or 100A breaker in this case)

A) What is the rating of the main panel?
B) DO NOT exceed this rating, less 20%.
C) Also, do a load test to determine the max. breaker size that you can
SAFELY install.

2) I am adding a few new circuits to said subpanel. I ran all the wire (14/2, about 75 feet), but my spool ran out and I came up about 15 feet short. Can I just solder some more 14/2 wire onto the end of it and cover it up with electrical tape? Or do I need to enclose the wire in a junction box and use wire nuts? This is in the crawlspace, if it matters.

A) Use the "J" box, bond the ground to the box.
B) "J" boxes, whether under the floor or in the attic, are to be located within
20' of the access opening.

mrcaptainbob :

THese would be 'accessible' if a hole were cut in the drywall to get to them...should the need arise. Would that have been an incorrect installation?

If the one in the attic is within 20' of the access and the comtents available from the attic, its acceptable. Those buried in the wall can have an extension box, and/or plaster ring added to bring them to the wall surface and accessable.

[mrcaptainbob]

Don't mean to hi-jack this thread, but......
I take it then that the ones that are in the ceiling of the 1'st floor would be an incorrect install. I planned on eliminating most of these anyway, but felt some of the harder to reach ones would be best left alone.

[kactuskid]

I take it then that the ones that are in the ceiling of the 1'st floor would be an incorrect install

If you have j-boxs that are in the ceiling between the first and second floors or in a wall cavity, and there is drywall installed over the tops of these so they are not accessible, then yes, this is definatly an incorrect installation. You should get rid of all these boxs or you need to extend the box face flush with the finished wall or ceiling and install a removable cover on them. You can paint the cover to blend in with the wall, but you can't drywall over the tops of them.

[mrcaptainbob]

WIll go that route then. It seemed foolish to have used those boxes rather than thread the wire from the outlets to the main panel. I wondered exactly how much they saved by useing them and splicing the wire. Not to mention the added expense of the wire nuts!! Well, that pales in comparison to the rats nests I've found inside of some of the wall cavities. The insulation was scraped back, new wire for an added outlet wrapped around the copper, it was then all black taped up. One of them was 2 inches from a wall outlet. Pitiful! Would've been safer to have it in a hidden junction box, I would think! Dissappointed on the one hand to find this stuff, but glad on the other to be finding it! Thanks for the help. (We can now return to the original thread!)

[Slickdonkey]

I just wanted to thank everyone for their advice in installing my subpanel. I did the work over the weekend and it went well, everything appears to be working.

One thing I wondered about is that the subpanel is only attached to the stud on one side. It seems like it would be a good idea to secure it a little better.

Thanks again for all your help.