Garage subpanel, 60 amp, couple questions

[Highbeam]

I just set the 100 amp siemens panel in my new barn this weekend. My setup goes like this:

1) 200 amp house panel, 60 amp breaker for barn.
2) 6/3 with ground romex to the outside wall of the house.
3) Transition to 1.5" conduit with THWN-2, same wire sizes and copper.
4) 24" cover over conduit underground to barn.
5) Conduit through slab to base of subpanel and into the 100 amp breaker of the subpanel(acts as a disconnect).

I put in two ground rods at the subpanel and tied them to the ground bar of the subpanel with #4 bare copper.

On the subpanel I removed the tie bar connecting the neutral and ground bars. I drove in the green screw which ties the ground bar to the panel.

1) Do I run the 10 gauge THWN ground wire from the house to the neutral bar or the ground bar in the subpanel? I assume ground bar but then the neutral will be bonded via the house panel.

2) Where the conduit ends at the house I used a 30 cubic inch LB. I made my splice inside the LB using wirenuts. I've never wire nutted #6 wires and I'm not real happy with how they work. Is this standard practice?

3) The LB is against the house with the back opening poking through the siding to the inside. Regular wirenuts okay or need I use those silicone filled ones? Is there a better connector for this that is more secure than a wirenut?

4) The 6/3 romex just enters the back of the LB. It is not clamped to the LB in any way. I can see into the LB and see the wirenuts through the big 1.5" opening. Is this okay? How close to the LB must my last staple be?

I will be getting a permit for this but our state inspectors don't answer questions, they just show up and approve/fail.

Thanks for your help folks. Before inspection I will be installing the lighting and outlet circuits. When you buy a permit here the single permit covers the subpanel plus five circuits so I want them installed before inspection.

 

[pattenp]

First I’d say the #6Cu romex is too small for 60A if the romex is within an insulated wall. If the romex is within insulation it needs to be sized from the 60C column which would be #4. #6Cu is good for 55A from the 60C column. If the romex is installed in air then the 75C column is used which #6 would be ok at 65A.
!. Ground runs from ground bar in sub to ground/neutral in main.
2. I’d use splice/reducer connectors and heat shrink tube. Your LB may be too small, you are suppose to leave at least 6” of wire out of the entry point for connecting/splicing.
3. see #2
4 use a threaded adapter on the LB and add a romex clamp to secure the cable where it enters the LB.

 

[njride]

you'll fail just on the romex connection to the lb, or lack there of. You need to use an approved connector at a minimum or better yet mount a little 6x6 jb on the inside wall(lb connected to the backside of the jb and the romex coming in the top or side with a standard romex connector and do your splice in that.

 

[pattenp]

If the LB is marked with its cubic inch capacity then it's okay to splice within the LB. Just be aware of the fill limits for the size. I believe you are over the max with having 6 #6 current carrying conductors plus the ground being spliced in a 30 cu inch conduit body.

 

[Highbeam]

The wire size chart says 55 amps with #6, okay, but then aren't you allowed to use the next size breaker which is 60?

You can splice in an LB if the LB is big enough. I am only splicing a total of four wires but are you saying that the code counts that as 8. Does anybody know what the minimum volume is that I need in the LB for this connection? If the LB is too small then I will have no choice but to mount another box inside the building.

NJRide: What is an approved connector? Are you talking about the wire nuts or about a way to attach the romex to the LB? If I use an additional Jbox for the splice point then I could easily use the little connector to hold the NM to the box. Otherwise the staples holding the wire to the stud within 12 inches is all I'd have.

 

[MrMark]

nm cable is always sized from the 60 degree column.

 

[pattenp]

Each wire entering a box and is terminated or spliced is counted once. Each wire that passes through will be counted once. So in your case you've got 8 but the ground is only counted once so you end up with a count of 7. For #6 you need 5 cubic inch of space for each conductor per 314.16(b) which will be 35 cubic inches.

 

[pattenp]

nm cable is always sized from the 60 degree column.

Good catch. I keep getting the SE 60C vs 75C insulation rule backwards in my head.

 

[pattenp]

The wire size chart says 55 amps with #6, okay, but then aren't you allowed to use the next size breaker which is 60?

You are right, you can use the next size up. The next size up is a no no if the conductors being protected are part of a branch circuit supplying more than one receptacle for cord-and-plug-connected portable loads.

Forget what I said in the first part of post #2. I had my head on backwards. I was going to up my a**, but that wasn't being fair to myself.

 

[Highbeam]

Each wire entering a box and is terminated or spliced is counted once. Each wire that passes through will be counted once. So in your case you've got 8 but the ground is only counted once so you end up with a count of 7. For #6 you need 5 cubic inch of space for each conductor per 314.16(b) which will be 35 cubic inches.

7 times 5 or 6 times 5 plus whatever the #10 ground requires?

I might be looking into a Jbox in the house. Ugh.

Also been researching the various ways to connect #6 other than with wire nuts. There are a few other ways.

I won't be landing the wires on the subpanel until I get this sorted out. I might need the length pulled into the jbox!

 

[Alchymist]

I

On the subpanel I removed the tie bar connecting the neutral and ground bars. I drove in the green screw which ties the ground bar to the panel.

Regular wirenuts okay or need I use those silicone filled ones? Is there a better connector for this that is more secure than a wirenut?

The green screw normally ties the neutral bus to the panel, and should be left out. The ground bars normally screw to the panel making their own panel connection that way.

On large wire like a #6, I use split nuts, taped with a layer of rubber tape and followed with a layer of plastic electrical tape.

 

[Highbeam]

The green screw normally ties the neutral bus to the panel, and should be left out. The ground bars normally screw to the panel making their own panel connection that way.

On large wire like a #6, I use split nuts, taped with a layer of rubber tape and followed with a layer of plastic electrical tape.

On this panel, there were two full sized bars connected by a tie bar. One of them had the green screw to make it bonded to the panel. I needed one ground bar tied to the panel and one neutral bar not bonded to the panel so I made the decision to use the bar with the green screw as my ground bar and remove the tie bar so that the other bar was not bonded to the panel.

There's no convention or nametag on the bar saying that one or the other must be the neutral or the ground bar in a subpanel arrangement but I agree, if this panel was used as a main panel, the bar with the green screw would have made a fine neutral bar.

I used a meter to verify that the one bar (my neutral) is not connected to the panel by some hidden screws.

As much as I dislike the idea of the split nuts being used and then having to tape them up to insulate them, it looks to be the best solution. If they made some sort of insulated terminal block then I would rather use that.

There are some special requirements to tape up the split nuts that seem pretty loose.

 

[njride]

NJRide: What is an approved connector? Are you talking about the wire nuts or about a way to attach the romex to the LB? If I use an additional Jbox for the splice point then I could easily use the little connector to hold the NM to the box. Otherwise the staples holding the wire to the stud within 12 inches is all I'd have.

You'll need a reducer for the lb so that you can thread a nm(romex) connecter into it to secure the romex.


I'm talking about attaching the romex to the LB, you cant just stick it in the hole in the conduit body and call it good, you need to use an approved connecter on the romex where it enters the LB. If you want to splice in the lb and youve figured that you are within the allowed fill than that's fine, I like a small jb better for the splice and as the guy said above split nuts are a good idea , but its legal to splice in the lb.

Heres the reducer that you need

https://www.cooper-electric.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10151&storeId=11201&productId=81722&langId=-1

 

[Aceman]

I don't see a way(legally) to use the LB. Unless you can find a plastic Romex connector to go into your LB I don't know how you'd bond(ground) the metal Romex connector.

I'd use a metal 6x6x4 3R box myself, or you could use a pvc box and throw a bond bushing on the metal Romex connector.

For the code junkies, this is in 250.4(A) in my 05 NEC.

 

[Highbeam]

That's pretty slick. If I end up being able to use the LB for my splice then that looks like a great way to restrain the romex and to plug the hole up a bit better. I'm a little hesitant to use metal parts though since the rest of the assembly is plastic and not grounded.

 

[Highbeam]

I don't see a way(legally) to use the LB. Unless you can find a plastic Romex connector to go into your LB I don't know how you'd bond(ground) the metal Romex connector.

I'd use a metal 6x6x4 3R box myself, or you could use a pvc box and throw a bond bushing on the metal Romex connector.

For the code junkies, this is in 250.4(A) in my 05 NEC.

I'm starting to think that this is a better idea for a few reasons. The 6x6x4 box that is. I can ground the box and then use a normal romex clamp where the romex enters the box. Splice inside the box using whatever means possible and hopefully not wire nuts.

Are those boxes available at home depot type stores? Do they have 1.5" knockouts?

 

[Charles (in GA)]

Make the splices with Polaris Connectors available at any good electrical supply house. Best way to splice heavy wires since sliced bread.

If you used a 1-1/2" LB then simply remove it, and use a bushing to upsize to a 2" or more LB and you gain the needed cu inches that way. Bush back down going thru the wall. I assume this is PVC conduit. Bush down going thru the wall and inside, as already mentioned, glue on a slip to female threaded bushing, and then a standard metal romex connector that is the correct size for your NM cable.

Charles

 

[Aceman]

I'm starting to think that this is a better idea for a few reasons. The 6x6x4 box that is. I can ground the box and then use a normal romex clamp where the romex enters the box. Splice inside the box using whatever means possible and hopefully not wire nuts.

Are those boxes available at home depot type stores? Do they have 1.5" knockouts?

No, the ones I use typically have concentric knockouts with 1/2, 3/4, and 1" holes. You'll have to open up one of the holes if you need to go larger.

Or you can buy j-boxes with no holes and just make your own with a holesaw. This would probably be your best bet.

 

[Highbeam]

I'm getting lots of great help here guys, thanks.

So does anybody know the volume required for this LB? Looks like 30 CI plus whatever the single #10 ground requires.

 

[Highbeam]

Make the splices with Polaris Connectors available at any good electrical supply house. Best way to splice heavy wires since sliced bread.

If you used a 1-1/2" LB then simply remove it, and use a bushing to upsize to a 2" or more LB and you gain the needed cu inches that way. Bush back down going thru the wall. I assume this is PVC conduit. Bush down going thru the wall and inside, as already mentioned, glue on a slip to female threaded bushing, and then a standard metal romex connector that is the correct size for your NM cable.

Charles

Those polaris blocks look perfect.

I did use PVC conduit so I suppose moving up to 2" is possible.

Is it okay to use a metal romex connector here that isn't grounded? Seems that it could cut into the romex and become energized.

 

[Charles (in GA)]

In doing some Googling looking for a PVC connector for Romex, I ran across this and this becomes an issue with the splices in the LB at all since it is outside.

300.9 Raceways in Wet Locations Above Grade.
Where raceways are installed in wet locations abovegrade, the interior of these raceways shall be considered to be a wet location. Insulated conductors and cables installed in raceways in wet locations abovegrade shall comply with 310.8(C).

This would mean that the NM is entering the LB which is outside and thus in a wet location. Sounds like the splice may need to be inside in a box, inside the wall or inside the house.

Is it okay to use a metal romex connector here that isn't grounded? Seems that it could cut into the romex and become energized.

See Aceman's post above. I had not given it any thought, but yes, that can happen. Did this when installing a new panel in my parents house after they passed away. Was done and threw the main and "boom" and a flash. Took me a while to locate it. I had over tightened a romex clamp on a NM and pinched it enough to either short the hot/neutral/ground, or to the clamp, not sure which.

Polaris connectors are still the best way to make the splice on cable this size.

Charles

 

[Highbeam]

Gotta admit I wasn't looking forward to cutting off the 1.5" LB but I will say that there are some "wet area" approved connection methods.

Metal box inside, and grounded, then use a metal romex clamp. Still need to cut the 1.5" hole.

I need to try and find those polaris connectors.

 

[Alchymist]

Make the splices with Polaris Connectors available at any good electrical supply house. Best way to splice heavy wires since sliced bread.

Around here the Polaris connectors are about 4 times the cost of the split bolts. Agreed they are nice, but expensive. Last time i saw them, they were in the neighborhood of $20-25 each. Perhaps they're cheaper where you are?

 

[pattenp]

How is this any different than SE exiting the building into the back of a meterbase that is on the outside of the wall. SE is not rated for wet location. Would not the meterbase be considered a wet location?

In doing some Googling looking for a PVC connector for Romex, I ran across this and this becomes an issue with the splices in the LB at all since it is outside.



This would mean that the NM is entering the LB which is outside and thus in a wet location. Sounds like the splice may need to be inside in a box, inside the wall or inside the house.



See Aceman's post above. I had not given it any thought, but yes, that can happen. Did this when installing a new panel in my parents house after they passed away. Was done and threw the main and "boom" and a flash. Took me a while to locate it. I had over tightened a romex clamp on a NM and pinched it enough to either short the hot/neutral/ground, or to the clamp, not sure which.

Polaris connectors are still the best way to make the splice on cable this size.

Charles

 

[Highbeam]

Picked up the metal 8x8x4 J-box and fittings to put the box on the dry side of the wall. It's going to be ugly since the wall thickness is only like 3/4" and the distance between the LB and the back of the J-box will be almost 2". This means that either the LB or the jbox will have to be pulled away from the wall and look stupid. Not sure which way I'll go but the large box means some demolition work inside the building. I do think that the job will be safer and better in the end, lots of room for a nice connection in that box.

The choices for connectors do not include polaris connectors at my local supply house. I could get the split bolts, compression sleeves, and wire nuts, but the apparent winner is these terminal lugs that are about the size of a tootsie roll and you shove a wire into each end, then tighten down a screw (like a terminal lug screw on the side) to squeeze the wires into the tootsie toll. So you would then slide shrink wrap over the whole tootsie toll and that's it. Not sure what they're called but it sure looks easier than trying to insulate those split bolts with tape and cost was about the same as split bolts. Any experiences with these things?

 

[pattenp]

Splice kit or splicer-reducer. This is what I was referring to in my first post.
Example: http://www.lowes.com/pd_34311-12704...urrentURL=/pl__0__s?Ntt=splice+kit&facetInfo= or http://www.homedepot.com/h_d1/N-5yc...splay?langId=-1&storeId=10051&catalogId=10053

 

[Highbeam]

That's the fitting. Reasonably cheap and removable, effective, no special tools. Much better than wire nuts.

Thanks for sticking with me folks.

 

[pattenp]

How is this any different than SE exiting the building into the back of a meterbase that is on the outside of the wall. SE is not rated for wet location. Would not the meterbase be considered a wet location?

I'm back to correct myself. SE is rated for wet locations. I looked at some that I have laying around and it's XHHW-2. Man, I have got to stop stating stuff before I check.

 

[Highbeam]

Okay so the junction box is in and the splices made. I used a pretty big 8x8x4" metal box and then the tootsie roll looking splice blocks from home depot for the splice covered by a thick piece of shrink wrap on each one. I used a long lighter to shrink the shrink wrap and it worked but I sure wish I would have used a small torch. I then landed all the wires on the subpanel and set my first 20 amp circuit breaker in place. Not sure what it will power but I just had to put one in before adding the cover panel.

Everything outside was covered in ice/frost since it was about 26 degrees outside in our wet environment and of course I'm doing everything by headlamp light since it gets dark here by 5pm.

Hope to throw in a few circuits and get my inspection next week.

Thanks for your help.