Proper transition from Romex to NMT?

[Noltz]

I'm plotting a 240v run to my attached garage from my main panel. Well, 2 runs actually; A 240 for a future lathe / mill (30A?), and a 40A line for a Generator in-feed with an interlock.

In the garage the electrical is surface mounted in NMT. I have two 1" holes drilled through the foundation for the NMT passing into the basement. My question is how do I properly switch from the 15' length of 8/3 Romex into NMT (which must be loose wires)? With the 120v run I just used a utility box and a NMT adapter in the basement. Is it the same requirements for 240 with 6 or 8 gauge?

 

[theoldwizard1]

With the 120v run I just used a utility box and a NMT adapter in the basement. Is it the same requirements for 240 with 6 or 8 gauge?

Yes, but I don't think you can use "wire nuts" and I don't think Wagos come that large either.

Old school is a split nut and two layers of "friction tape" (Scotch 1755). Cheap, it works and last a long time if done correctly.

Polaris connectors are usually for large conductors.

There are crimp **** splice connector (typically un-insulated) in that size, but the problem is finding crimpers that big.

EDIT : FOUND THEM ! They are called "splicer reducers". They come in many sizes, but this is probably what you want.



ASE-ALCUL Splicer Reducer - Home Depot $6/Quantity 2

Again 2 layer of friction tape or 2 layers of Scotch 88 or 2 layers of rubber splicing tape.

 

[Noltz]

Well, something I'd considered is since the 8-3 will probably be romex originally (lots of Hot Tubs being upgraded = good used wire for cheap), I'm now wondering if I have to break the wire at all. Just run romex into a box, secure it and strip the sheathing onward down the NMT. Do I have to have a break in the box?

 

[Terry D]

I'm plotting a 240v run to my attached garage from my main panel. Well, 2 runs actually; A 240 for a future lathe / mill (30A?), and a 40A line for a Generator in-feed with an interlock.

In the garage the electrical is surface mounted in NMT. I have two 1" holes drilled through the foundation for the NMT passing into the basement. My question is how do I properly switch from the 15' length of 8/3 Romex into NMT (which must be loose wires)? With the 120v run I just used a utility box and a NMT adapter in the basement. Is it the same requirements for 240 with 6 or 8 gauge?

You must mount a box on the conduit and transition from one method to the other. Make sure it is big enough for the splices. If you use metal, be sure to ground the box. The big blue wire nuts will be fine for splicing 2 #8's

 

[Noltz]

Okay! And do I have to make a splice in that box or can I run continuously from load center to my end points? Assume I use plastic box for this to avoid the need to ground it. Just seems silly to make a connection when continuous is available.

 

[Terry D]

Okay! And do I have to make a splice in that box or can I run continuously from load center to my end points? Assume I use plastic box for this to avoid the need to ground it. Just seems silly to make a connection when continuous is available.

You can put romex in conduit. If there are alot of bends, it can be a PITA

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[Noltz]

I'm expecting to be using the 240 for electric vehicles charging at some point, so I wanted to make sure its compliant & has maximum capacity. I've read for heat dissipation its best to have the wires free. I'm also going with 1" NMT for room / heat mitigation.

 

[sberry]

Says you got to protect cables, could use a pipe as a sleeve, could use decorative sheet metal or wood trim. You can wire nut but nothing is as good as an.uninterrupted wire. You probably need inch for an 8 cable

 

[wyliesdiesels]

Yes, but I don't think you can use "wire nuts" and I don't think Wagos come that large either.

Old school is a split nut and two layers of "friction tape" (Scotch 1755). Cheap, it works and last a long time if done correctly.

Polaris connectors are usually for large conductors......

why not?

ever seen the large blue ideal 454 wire nuts? good for 2 #8s

https://www.homedepot.com/p/Ideal-454-Blue-Wing-Nut-Wire-Connectors-25-Pack-30-454P/202894280

 

[mc4life27]

You can put romex in conduit. If there are alot of bends, it can be a PITA

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You can one run romex in the out jacket inside of Conduit if the run is 10 feet or shorter. But technically your not supposed to strip the jacket and do a longer run with it because whatever company the romex is did not pay to have the single wire certified and they are not independently labeled with all the specs like it is if you buy single wire run. Well that’s the code for ****** CA. Also they do make wire nuts for 8 Gauge wire I have some right in front of me. Now if it’s not one straight wire run and you have to splice in wire they splices need to be in a junction box so that they are protected and can not be messed with.


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[wyliesdiesels]

You can one run romex in the out jacket inside of Conduit if the run is 10 feet or shorter. But technically your not supposed to strip the jacket and do a longer run with it because whatever company the romex is did not pay to have the single wire certified and they are not independently labeled with all the specs like it is if you buy single wire run. Well that’s the code for ****** CA. Also they do make wire nuts for 8 Gauge wire I have some right in front of me. Now if it’s not one straight wire run and you have to splice in wire they splices need to be in a junction box so that they are protected and can not be messed with.


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Ummm what?

There is no 10’ max for NM-b in conduit code in the NEC.

And wire isnt certified, it is LISTED...

 

[Noltz]

...

EDIT : FOUND THEM ! They are called "splicer reducers". They come in many sizes, but this is probably what you want.



ASE-ALCUL Splicer Reducer - Home Depot $6/Quantity 2

Again 2 layer of friction tape or 2 layers of Scotch 88 or 2 layers of rubber splicing tape.

This is exactly what I needed to see. Solid connectors that I'm comfortable carrying big current for a future EV. Thanks!

 

[rlitman]

Yes, but I don't think you can use "wire nuts" and I don't think Wagos come that large either.

Old school is a split nut and two layers of "friction tape" (Scotch 1755). Cheap, it works and last a long time if done correctly.

Polaris connectors are usually for large conductors.

There are crimp **** splice connector (typically un-insulated) in that size, but the problem is finding crimpers that big.

EDIT : FOUND THEM ! They are called "splicer reducers". They come in many sizes, but this is probably what you want.



ASE-ALCUL Splicer Reducer - Home Depot $6/Quantity 2

Again 2 layer of friction tape or 2 layers of Scotch 88 or 2 layers of rubber splicing tape.

Wire nuts can be used on two #8. You just need the right size. Those aluminum splicer reducers are great. Rather than tape, I suggest 600V rated heat shrink. It makes for a tighter package that's easier to manage in the box.

As for NMT, WTH is that? I don't think it means Nordic Mobile Telephone.

 

[Terry D]

Wire nuts can be used on two #8. You just need the right size. Those aluminum splicer reducers are great. Rather than tape, I suggest 600V rated heat shrink. It makes for a tighter package that's easier to manage in the box.

As for NMT, WTH is that? I don't think it means Nordic Mobile Telephone.

Im thinking he means PVC

 

[rlitman]

Im thinking he means PVC

As in non-metallic cable tray? I don't see a way to guess here. If we're talking tray, Romex CAN be put in it as-is, so long as it meets the max fill requirements (keeping in mind that the circular area of Romex is huge compared to the wire itself). But as stated above, you can't go stripping the jacket off more than a few feet of it.

 

[Terry D]

As in non-metallic cable tray? I don't see a way to guess here. If we're talking tray, Romex CAN be put in it as-is, so long as it meets the max fill requirements (keeping in mind that the circular area of Romex is huge compared to the wire itself). But as stated above, you can't go stripping the jacket off more than a few feet of it.

Im thinking just Schedule 40 PVC conduit

 

[wyliesdiesels]

Im thinking he meant ENT- electrical non-metallic tubing aka smurf tube but changed the acronym letters to NMT= non-metallic tubing???

 

[Terry D]

You can one run romex in the out jacket inside of Conduit if the run is 10 feet or shorter. But technically your not supposed to strip the jacket and do a longer run with it because whatever company the romex is did not pay to have the single wire certified and they are not independently labeled with all the specs like it is if you buy single wire run. Well that’s the code for ****** CA. Also they do make wire nuts for 8 Gauge wire I have some right in front of me. Now if it’s not one straight wire run and you have to splice in wire they splices need to be in a junction box so that they are protected and can not be messed with.


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There is nothing in the NEC saying you cannot install NM-b in conduit. Local jurisdiction can override it though, St Louis County being one of them. Their thinking is there is a good chance of damaging it trying to install it. We are only allowed to sleeve it in conduit, for a short run, for physical protection, Example a surface mounted dryer receptacle in a basement. As far as installing it conduit, even if its allowed in the area im working in, for a long run I don't do it, I will put THWN in that conduit and a J-box to transition between the 2 wiring methods. We are also aware that they make wire nuts for (2) #8's. They are the big blues. And what do you have against California.

 

[Terry D]

Im thinking he meant ENT- electrical non-metallic tubing aka smurf tube but changed the acronym letters NMT= non-metallic tubing???

Gotcha

 

[rlitman]

Im thinking he meant ENT- electrical non-metallic tubing aka smurf tube but changed the acronym letters NMT= non-metallic tubing???

Surface mounted? I sure hope not.

In a garage, I've seen plastic Wiremold trays used for surface mounting. I'm not a fan of the stuff, but it is what it is.

 

[mcbane]

For a few extra $$ you can get insulated connectors that take anything from #14 to 2/0. https://www.hubbell.com/burndy/en/P...inals/Bolted/Vinyl-Insulated/1PL202/p/2021417

 

[Terry D]

Surface mounted? I sure hope not.

In a garage, I've seen plastic Wiremold trays used for surface mounting. I'm not a fan of the stuff, but it is what it is.

Yeah i agree, surface mounted smurf tube, that would look like ****.

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[nadogail]

Thanks for sharing.

 

[rlitman]

For a few extra $$ you can get insulated connectors that take anything from #14 to 2/0. https://www.hubbell.com/burndy/en/P...inals/Bolted/Vinyl-Insulated/1PL202/p/2021417

There was a comment above about Polaris connectors. These are the same idea, just a different brand.

 

[alfredeneuman]

In the USA, ENT has to be protected against physical damage, same as romex, and can't just be run on the surface without protection.
I'd be surprised if it wasn't the case in Canada as well

 

[Noltz]

Thanks for everyones feedback! As some of you noted, I've mistakenly been calling ENT as NMT (non-metalic tube). I've been calling NMT that for ages and I've never been corrected. It's only when I started reading here & finding products called ENT, like smurf tube, that I realized my mistake. So thank you to those who caught that and pointed it out. Something new every day, right?

In the USA, ENT has to be protected against physical damage, same as romex, and can't just be run on the surface without protection.
I'd be surprised if it wasn't the case in Canada as well

Really? I've seen several surface mount ENT installs in commercial buildings. I often wonder why they're not better supported because the ENT sags. An electrician (at the shop I work at) has ENT run for a 30A 240v outlet for our backup compressor. For myself it wouldn't be hard to build a guard to protect the ENT if it's an issue. Either box it in or a barrier on stand-offs to protect against impact. Is this better practice rules or actual code?

The garage today; https://www.dropbox.com/s/xa3516x84nwghn9/20200502_190723.jpg

The surface mount ENT I've run has worked out quite well in my opinion. It's straight, clean and well supported. All connections are glued. The circuit is protected by a GFI plug behind my toolbox, which I did because these plugs are quite low and in a perfect storm might get splashed by snow sliding off a parked car. Compared to a lot of commercial shops I've been in I feel like this is actually overkill.

 

[Terry D]

Thanks for everyones feedback! As some of you noted, I've mistakenly been calling ENT as NMT (non-metalic tube). I've been calling NMT that for ages and I've never been corrected. It's only when I started reading here & finding products called ENT, like smurf tube, that I realized my mistake. So thank you to those who caught that and pointed it out. Something new every day, right?



Really? I've seen several surface mount ENT installs in commercial buildings. I often wonder why they're not better supported because the ENT sags. An electrician (at the shop I work at) has ENT run for a 30A 240v outlet for our backup compressor. For myself it wouldn't be hard to build a guard to protect the ENT if it's an issue. Either box it in or a barrier on stand-offs to protect against impact. Is this better practice rules or actual code?

The garage today; https://www.dropbox.com/s/xa3516x84nwghn9/20200502_190723.jpg

The surface mount ENT I've run has worked out quite well in my opinion. It's straight, clean and well supported. All connections are glued. The circuit is protected by a GFI plug behind my toolbox, which I did because these plugs are quite low and in a perfect storm might get splashed by snow sliding off a parked car. Compared to a lot of commercial shops I've been in I feel like this is actually overkill.

That looks like PVC conduit. Is it flexible or solid

 

[Noltz]

It is schedule 40 PVC. Its mildly flexible but you can't crush it or bend it easily. It's outdoor rated (above ground) and I have individual conductors within.

 

[Terry D]

It is schedule 40 PVC. Its mildly flexible but you can't crush it or bend it easily. It's outdoor rated (above ground) and I have individual conductors within.

Thats not ENT. It is fine to have it exposed on walls. ENT or smurf tube is a blue semi flexible tubing for inside of walls

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[rlitman]

It is schedule 40 PVC. Its mildly flexible but you can't crush it or bend it easily. It's outdoor rated (above ground) and I have individual conductors within.

Yep. Plain old PVC conduit.

Thats not ENT. It is fine to have it exposed on walls. ENT or smurf tube is a blue semi flexible tubing for inside of walls

Exactly. PVC is fine exposed. Smurf tube, no.

THIS is ENT:

 

[mcbane]

There was a comment above about Polaris connectors. These are the same idea, just a different brand.

Are you referring to the comment that said Polaris is a large gauge solution? Didn’t know that Polaris now offers connectors for light gauge conductors and trusted that earlier comment. So I tried to help. A thousand pardons.


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[Noltz]

AH! Learning more every day here. Thank you all.

 

[Norcal]

Thats not ENT. It is fine to have it exposed on walls. ENT or smurf tube is a blue semi flexible tubing for inside of walls

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It is only blue if it’s made by Carlon, gray if made by others, just like pink fiberglass insulation is only made by Owens-Corning as the color is a trademark.

 

[alfredeneuman]

It is schedule 40 PVC. Its mildly flexible but you can't crush it or bend it easily. It's outdoor rated (above ground) and I have individual conductors within.

Is there really (as it appears to be) just 1 strap in the approx center?
By the the location shown in the photo, it would have been required to be Sch80 by the NEC

 

[Noltz]

Is there really (as it appears to be) just 1 strap in the approx center?
By the the location shown in the photo, it would have been required to be Sch80 by the NEC

I used https://www.commercial-industrial-supply.com/resource-center/pvc-pipe-support-spacing-guide/ this guide and found every 4 feet for ½" Sch. 40 up 100°F. I am 8' between plugs. Would you recommend tighter spacing anyway? I'm always open to doing it better. If you're concerned about temperature, it stays quite cool in the garage. 3 sides, including above, are climate controlled. The exterior wall is extremely well shaded by tall maples & pines, and an evergreen hedge is 4' from my wall. My garage door is north facing & insulated, with the slab directly on grade.

 

[alfredeneuman]

I used https://www.commercial-industrial-supply.com/resource-center/pvc-pipe-support-spacing-guide/

The temperature issue doesn't effect such a short piece.
The question as to supports could be better answered from someone who is familiar with the CEC, but the maximum distance between supports is 3' by the NEC

 

[Noltz]

The temperature issue doesn't effect such a short piece.
The question as to supports could be better answered from someone who is familiar with the CEC, but the maximum distance between supports is 3' by the NEC

How interesting! So when I did my initial search for spacing the charts said 4' for ½". I included the chart in my post. But you said 3, so I searched that up and it *does* say within 3' of a box, etc. So I'll have to add a couple supports there, and elsewhere. Thanks for the tip.

 

[Noltz]

UPDATE!

Finally got a few hours to work on the project. I had a licensed electrician come in to quote the job. He took a good look at what I was doing and said I could continue to run the electrical as I was but I had to add a lot more clamps. According to CEC it's 750mm, or 29.5", between conduit straps on a horizontal for anything up to 1". So I'm installing them every 24" for easy spacing.

I've tried for 20 minutes to get my photos to load here but they're not. I'm sorry. I'm guessing I don't have enough posts? Anyway, simple links;

https://ibb.co/dWwzZZV
https://ibb.co/CbkRBPC
https://ibb.co/Njs9G2R
https://ibb.co/VTzXTYw
https://ibb.co/CKcXY3W

So I've made a mistake and I'm trying to minimize it here; I drilled the ½" hole in the middle of the two 1" holes instead of to the right of them. This is causing an ugly cross-over. What is the best method of bumping the ½" conduit over the 1"? I have not yet glued the ½" straight section here. (although the 90° on the JB is). Thoughts?

 

[grounded-b]

How interesting! So when I did my initial search for spacing the charts said 4' for ½". I included the chart in my post. But you said 3, so I searched that up and it *does* say within 3' of a box, etc. So I'll have to add a couple supports there, and elsewhere. Thanks for the tip.

The chart you referred to, is for plumbing pipes. It doesn't apply to electrical conduits.

Steve

 

[Noltz]

The chart you referred to, is for plumbing pipes. It doesn't apply to electrical conduits.

Steve

The electrician was good enough to just give me the exact code and it's every 750mm, or 29.5". He asked for straps every 2', so that's what I'm doing. I ran out last night. I did get the generator wire run from the inlet box to the laundry room, so I'll move the breakers this weekend when nobody is home so I cam shut off the power.