Junction Box?

[ddawg16]

Sorry I don't have better pictures.....but I will try to 'paint' a picture so you understand what I'm trying to do....

As some of you recall, I'm doing a 2-story addition to my house (garage related because I'm using my garage to support the construction....right?). I poured concrete last week. My foundation is a combination of slab and crawl space.....the slab is for the family room....a place my kids can jump...bounce...Wii...etc...and we don't hear the noise of the floor bouncing....the room will also have a 9' ceiling. The rest of the 1st floor is raised with a crawl space....makes plumbing easier.

To the left of this pic are a couple of gray PVC pipes coming up out of the corner (out of view) of the concrete. My meter will be in this location....one pipe caries the #6 wire to the garage....the other PVC pipe is a 2" and you can see it sticking up in the corner of the center crawlspace....that pipe is going to carry wires to the old part of the house and part of the addition. I figure it's easier to run Romex from this location than from the corner of the house.

Here is a closer look at the pipe.

In addition, my plumbing is also going to be in this area....if you look straight back....my sewer pipe will come out of the base of the footing and straight back to the wall....picking up a few drains along the way.

I want to install a junction box on the side of the slab just below the floor. My 'intent' is to run THHN wire to the junction box where I can then connect some of the Romex for the addition. Some of the THHN will just pass through and go to the front of the house via more conduit.

Questions are:

Any code issues having a junction box down there?

Do I splice wires just using wire nuts and tape? Or can I use a 'terminal strip' rated for the size wire?

 

[Aceman]

Just so we're clear, you're not pulling any Romex in the conduit? That's simply a chase to get THHN back to the panel?

Any code issues having a junction box down there?

Do I splice wires just using wire nuts and tape? Or can I use a 'terminal strip' rated for the size wire?

No problem having a j-box down there as long as it's accessible.

I did a panel change in an office once that required me to use 24x24x4 j-boxes in the attic and crawl. I ran all the existing Romex to terminal blocks in the j-box then extended them from there to the new panel location. The terminal blocks came out MUCH CLEANER than a big wad of wire nuts IMO. I'd also put a ground bar in there too. That'll save you from trying to twist a bunch of grounds together under one or two wirenuts.

 

[mrb]

id put a ground bar in the jbox and use wirenuts for the rest. (dont tape your wirenuts)

how many circuits are in here? Are you going to run into derating issues putting them all in the same conduit?

 

[ishiboo]

Just so we're clear, you're not pulling any Romex in the conduit? That's simply a chase to get THHN back to the panel?



No problem having a j-box down there as long as it's accessible.

I did a panel change in an office once that required me to use 24x24x4 j-boxes in the attic and crawl. I ran all the existing Romex to terminal blocks in the j-box then extended them from there to the new panel location. The terminal blocks came out MUCH CLEANER than a big wad of wire nuts IMO. I'd also put a ground bar in there too. That'll save you from trying to twist a bunch of grounds together under one or two wirenuts.

What terminal strip did you use, and how did you mount it? I'm getting ready to relocate/replace my main panel (rusted BH to QO), and all the circuits will need to be extended.

 

[ddawg16]

Just so we're clear, you're not pulling any Romex in the conduit? That's simply a chase to get THHN back to the panel?

Very clear....NO romex in the conduit....THHN only....most likely stranded since I have a bunch of it.....and it's a lot easier to pull.

I have 6 ckts to pull to the front of the house...5 for the kitchen alone. (I have removed all of the kitchen ckts from the original house wiring)

I'm going to have several walls that are 6" wide on the 1st floor....so it's going to be easy putting a vertical conduit run in them.

As for terminal blocks....I have a bunch of Entralec and AB DIN mounted terminal blocks that are good for up to 10 Awg wire. Much easier (and safer) to use than wire nuts.

 

[ishiboo]

Very clear....NO romex in the conduit....THHN only....most likely stranded since I have a bunch of it.....and it's a lot easier to pull.

I have 6 ckts to pull to the front of the house...5 for the kitchen alone. (I have removed all of the kitchen ckts from the original house wiring)

I'm going to have several walls that are 6" wide on the 1st floor....so it's going to be easy putting a vertical conduit run in them.

As for terminal blocks....I have a bunch of Entralec and AB DIN mounted terminal blocks that are good for up to 10 Awg wire. Much easier (and safer) to use than wire nuts.

Never thought to use DIN-mount, would that be okay with an electrical inspector? Obviously they're used heavily in industrial equipment/automation, but I've never seen one in a home junction box before

I've only seen stranded installed in them, do most accept stranded and solid?

 

[Aceman]

I used DIN-rail mount terminal blocks rated for #10 and 25-30 amps or so. They'e not very expensive, so it's worth it to me to make sure they are a little oversize and won't melt down.

 

[brs]

By chance, do you have a photo of DIN mounted terminal blocks you used in place of junction boxes?

 

[ddawg16]

Here is an 'affordable' type.....I'm partial to Allen Bradley....but the Automation Direct version are fine for the residential user...

http://www.automationdirect.com/adc...DIN-Rail_Terminal_Blocks_(order_by_Block_Type)

Note....you will need DIN rail to mount them....but once you start using DIN stuff....it all becomes pretty easy.

 

[lakee911]

OP, unless you upsize the wire, you're going to run into derating issues if you want to pull six circuits into a single conduit all the way back to the house. As a rule of thumb, you can generally put two circuits into the same raceway without derating.

The JB will also have to be properly sized for the number of current carrying conductors. The sizing requirements are in 370.16 of the NEC. If you use a terminal box with terminals, you'll already likely be large enough if you can get the terminals in there.


You'll likely find it's cheaper to just run NMB ("Romex") cable from the new panel to the house.

Mason, your pics aren't loading for me.

 

[wyliesdiesels]

OP, unless you upsize the wire, you're going to run into derating issues if you want to pull six circuits into a single conduit all the way back to the house. As a rule of thumb, you can generally put two circuits into the same raceway without derating.

You mean he will have to upsize the wire BECAUSE of derating? Since he will have 12 current carrying conductors in a conduit, they will have to be derated by 50%. And with 90c deg. conductors, derating only has to be done when there are more than 9 current carrying conductors in a conduit.

You'll likely find it's cheaper to just run NM-B ("Romex") cable from the new panel to the house.

Mason, your pics aren't loading for me.

NM-B/Romex is not permitted to be run in conduit when in a wet location such as in the OPs situation where the conduit goes underground.

 

[brs]

Here is an 'affordable' type.....I'm partial to Allen Bradley....but the Automation Direct version are fine for the residential user...

http://www.automationdirect.com/adc...DIN-Rail_Terminal_Blocks_(order_by_Block_Type)

Note....you will need DIN rail to mount them....but once you start using DIN stuff....it all becomes pretty easy.

I guess my question was about how you bussed them.

I envision a stack of terminal blocks about 15 long.
5x Black/White/Green, repeating in that order, each color is on it's own bus.

I can't see how that would be done without extensive jumpering. I could see 5 of each color jumpered together with separators on each side, but it wouldn't fit as nicely.

 

[doctorjdog]

Very clear....NO romex in the conduit....THHN only....most likely stranded since I have a bunch of it.....and it's a lot easier to pull.

I have 6 ckts to pull to the front of the house...5 for the kitchen alone. (I have removed all of the kitchen ckts from the original house wiring)

I'm going to have several walls that are 6" wide on the 1st floor....so it's going to be easy putting a vertical conduit run in them.

As for terminal blocks....I have a bunch of Entralec and AB DIN mounted terminal blocks that are good for up to 10 Awg wire. Much easier (and safer) to use than wire nuts.

I know this was a while ago, but did you ever do this? My panel has too much stuff in it, some wires are wire nutted, and I wanted to put energy monitor clamps on wires. I thought I might run all my home's romex into a box with a din rail and then run THHN back to the panel so it looks clean. If you did go ahead with this option, can you post a pic so I can see what it looks like?

 

[ddawg16]

I know this was a while ago, but did you ever do this? My panel has too much stuff in it, some wires are wire nutted, and I wanted to put energy monitor clamps on wires. I thought I might run all my home's romex into a box with a din rail and then run THHN back to the panel so it looks clean. If you did go ahead with this option, can you post a pic so I can see what it looks like?

I actually did do this....this is an old pic....a couple more ckt's have been added..but you should get the idea

This is a pull box under the addition to the house.

 

[doctorjdog]

I actually did do this....this is an old pic....a couple more ckt's have been added..but you should get the idea

This is a pull box under the addition to the house.

Thanks for the pic. It looks like in this that whole red block connects all the hots? I was under the impression they all just fed straight through and were individual, so I could have 1 block for each circuit.

 

[nadogail]

Thanks for the pic. It looks like in this that whole red block connects all the hots? I was under the impression they all just fed straight through and were individual, so I could have 1 block for each circuit.

I like the looks of the box, it reminds me of some of the ships I worked on during my Shipyard Days.

 

[ddawg16]

I like the looks of the box, it reminds me of some of the ships I worked on during my Shipyard Days.

I can go either way...I just need to remove a jumper. That box is for outside utility stuff. It's fed from a GFCI and initially just fed the lights in the crawl space. I have plans to add an outlet on the back wall