A few DIY NEMA 14-50 install questions

[NowIsGood]

Hi all. I’m picking up my Performance Model 3 tomorrow afternoon (woohoo!) and am hoping to complete a DIY install of a NEMA 14-50 outlet today. Lots of useful info on this forum, but I have a few questions nonetheless.

A little background:

• For whatever reason, there’s a very nice empty metal outlet box already installed in my garage, just one foot below where the panel is mounted on the wall outside. So I literally just need to run one foot of wire from the panel to the outlet.
• For materials, I’ve got an Eaton 50A breaker, about 10 feet of 6/3 NM-B Romex, and one of the Tesla recommended outlets (Hubbell HBL9450A).

Here are my questions. Photos below give context.

1. Location of breaker in panel? There’s one remaining double-breaker spot in my panel, right at the top. But I’ll be running the wire through a knockout in the bottom of the panel (already knocked out, with a grommet in place, by the prior homeowner). Should I go ahead and use the spot at the top for my new breaker? Or would it make more sense to move the breaker from the bottom of the panel (for the AC), which has wire running to the top of the panel anyway, and use that bottom spot for my new breaker?

2. Orientation of outlet? I know Tesla says to install the outlet with the ground to the top. But I believe that’s so the cord will hang properly. Here, the existing outlet box is installed just above a shelf, so if I install the outlet per the Tesla recommendation, I don’t think I’ll be able to plug the adapter in. Also, I think the prior homeowner installed the outlet box sideways, based on the screw holes of the outlet box. But that seems perfect for me, as the whole adapter can sit on the shelf sideways, so there’ll be no strain on the connection between the plug and the outlet. Any problem with installing the outlet sideways in this situation?

3. Romex in conduit? As mentioned above, I have a length of 6/3 NM-B Romex. which I procured before discovering today that there’s actually metal conduit inside the wall running the one foot from the panel to the outlet box. I’ve read a lot of conflicting, confusing, and maybe confused information and opinions on this. The smartest opinions (on their face, to me), are that if it’s a situation where Romex would be okay, then it’s okay to put it in conduit. The argument against it seems to be heat build-up but as some have pointed out, it’s already sheathed in rubber and putting it inside metal conduit isn’t going to add that much more heat insulation than it already has. And in any case, I’m looking at a run of about one foot, so it really shouldn’t matter. I could also “unsheath” the Romex, but is that really necessary? (And then it would probably not be code-compliant as the individual wires aren’t labeled THHN). True, I could just go get some different wire, but I’m not sure I can procure it before I can get my car, so if there’s an acceptable installation with what I’ve got I’d like to proceed with it.

Thanks so much!

 

[Dana1]

Hi all. I’m picking up my Performance Model 3 tomorrow afternoon (woohoo!) and am hoping to complete a DIY install of a NEMA 14-50 outlet today. Lots of useful info on this forum, but I have a few questions nonetheless.

A little background:

• For whatever reason, there’s a very nice empty metal outlet box already installed in my garage, just one foot below where the panel is mounted on the wall outside. So I literally just need to run one foot of wire from the panel to the outlet.
• For materials, I’ve got an Eaton 50A breaker, about 10 feet of 6/3 NM-B Romex, and one of the Tesla recommended outlets (Hubbell HBL9450A).

Here are my questions. Photos below give context.

1. Location of breaker in panel? There’s one remaining double-breaker spot in my panel, right at the top. But I’ll be running the wire through a knockout in the bottom of the panel (already knocked out, with a grommet in place, by the prior homeowner). Should I go ahead and use the spot at the top for my new breaker? Or would it make more sense to move the breaker from the bottom of the panel (for the AC), which has wire running to the top of the panel anyway, and use that bottom spot for my new breaker?

2. Orientation of outlet? I know Tesla says to install the outlet with the ground to the top. But I believe that’s so the cord will hang properly. Here, the existing outlet box is installed just above a shelf, so if I install the outlet per the Tesla recommendation, I don’t think I’ll be able to plug the adapter in. Also, I think the prior homeowner installed the outlet box sideways, based on the screw holes of the outlet box. But that seems perfect for me, as the whole adapter can sit on the shelf sideways, so there’ll be no strain on the connection between the plug and the outlet. Any problem with installing the outlet sideways in this situation?

3. Romex in conduit? As mentioned above, I have a length of 6/3 NM-B Romex. which I procured before discovering today that there’s actually metal conduit inside the wall running the one foot from the panel to the outlet box. I’ve read a lot of conflicting, confusing, and maybe confused information and opinions on this. The smartest opinions (on their face, to me), are that if it’s a situation where Romex would be okay, then it’s okay to put it in conduit. The argument against it seems to be heat build-up but as some have pointed out, it’s already sheathed in rubber and putting it inside metal conduit isn’t going to add that much more heat insulation than it already has. And in any case, I’m looking at a run of about one foot, so it really shouldn’t matter. I could also “unsheath” the Romex, but is that really necessary? (And then it would probably not be code-compliant as the individual wires aren’t labeled THHN). True, I could just go get some different wire, but I’m not sure I can procure it before I can get my car, so if there’s an acceptable installation with what I’ve got I’d like to proceed with it.

Thanks so much!

Wouldn’t strip Cord of it’s protective cover and I think it’s always a good idea for a cord to not have weight hanging from it. I wouldn’t mess with existing breakers, especially if they’re older.

 

[Sophias_dad]

Stripping the wire isn't allowed, because the conductors aren't rated for use without their romex sheath.

The good news is you can run down to home depot and get a couple feet of THHN or other similar individual conductors, and you can send those through the conduit easily. Even on the east coast, Lowes and HD are open another two hours.

Installing the outlet sideways is fine, especially if you can put the UMC on the shelf next to the outlet.

Position of the breaker doesn't matter.

Be VERY careful to torque the conductor screws properly, preferably with a torque wrench, both on the outlet and the breaker(s) you touch.

 

[ksb467]

1) use the top one
2) laying on side will be good
3) others already answered

 

[ewoodrick]

In many instances, the orientation of a plug is debated, whether ground on top or bottom. But sideways isn't the right answer. The issue is what happens if something metallic falls between the plug and wall. With ground up, it is protected. With ground down, the circuit will probably trip. With sideways, the metal will become dangerous.
I do hope that the view is from the top of the bench, not the garage floor. I would not like to see that on the floor, too much chance for water to get near the plug.
If it is the floor, I'd seriously think about moving it to somewhere will it will meet code.

 

[NowIsGood]

Thanks, all! Exactly the advice I needed! I did have time to pick up separate wires (got separate insulated #6 by the foot in red, white and black from Platt Electric, and #10 bare solid by the foot from Home Depot). I'll install it in the morning, with the new breaker on the top, not moving any other ones. The outlet is above a shelf that is a good 18" above the floor, and under another shelf that's flush to the wall, so it's safe from water and pretty well protected from the top also, so sideways seems pretty safe in this instance, but I'll consider cutting into the shelf so that I can install it with the ground up, though I think that might require spinning the box 90 degrees and that won't be easy.

 

[eprosenx]

Hi all. I’m picking up my Performance Model 3 tomorrow afternoon (woohoo!) and am hoping to complete a DIY install of a NEMA 14-50 outlet today. Lots of useful info on this forum, but I have a few questions nonetheless.

A little background:

• For whatever reason, there’s a very nice empty metal outlet box already installed in my garage, just one foot below where the panel is mounted on the wall outside. So I literally just need to run one foot of wire from the panel to the outlet.
• For materials, I’ve got an Eaton 50A breaker, about 10 feet of 6/3 NM-B Romex, and one of the Tesla recommended outlets (Hubbell HBL9450A).

Here are my questions. Photos below give context.

1. Location of breaker in panel? There’s one remaining double-breaker spot in my panel, right at the top. But I’ll be running the wire through a knockout in the bottom of the panel (already knocked out, with a grommet in place, by the prior homeowner). Should I go ahead and use the spot at the top for my new breaker? Or would it make more sense to move the breaker from the bottom of the panel (for the AC), which has wire running to the top of the panel anyway, and use that bottom spot for my new breaker?

2. Orientation of outlet? I know Tesla says to install the outlet with the ground to the top. But I believe that’s so the cord will hang properly. Here, the existing outlet box is installed just above a shelf, so if I install the outlet per the Tesla recommendation, I don’t think I’ll be able to plug the adapter in. Also, I think the prior homeowner installed the outlet box sideways, based on the screw holes of the outlet box. But that seems perfect for me, as the whole adapter can sit on the shelf sideways, so there’ll be no strain on the connection between the plug and the outlet. Any problem with installing the outlet sideways in this situation?

3. Romex in conduit? As mentioned above, I have a length of 6/3 NM-B Romex. which I procured before discovering today that there’s actually metal conduit inside the wall running the one foot from the panel to the outlet box. I’ve read a lot of conflicting, confusing, and maybe confused information and opinions on this. The smartest opinions (on their face, to me), are that if it’s a situation where Romex would be okay, then it’s okay to put it in conduit. The argument against it seems to be heat build-up but as some have pointed out, it’s already sheathed in rubber and putting it inside metal conduit isn’t going to add that much more heat insulation than it already has. And in any case, I’m looking at a run of about one foot, so it really shouldn’t matter. I could also “unsheath” the Romex, but is that really necessary? (And then it would probably not be code-compliant as the individual wires aren’t labeled THHN). True, I could just go get some different wire, but I’m not sure I can procure it before I can get my car, so if there’s an acceptable installation with what I’ve got I’d like to proceed with it.

Thanks so much!

Agreed I would probably do the top breaker spot just to not have to mess with anything. There is also some logic to putting the high draw breakers closest to the inlet feeds (though I would not worry about this too much and the advantage to the bottom would be less wire fill in the breaker panel). It looks like that top breaker position is able to accept tandem breakers in the event that you ever need to add more circuits. Eaton makes quad tandems in up to 50a just FYI.

I wanted to call out that the plastic strain relief in the bottom does not look like what I would expect for a conduit. It looks like plastic strain relief for a romex wire. It also looks like only a 1/2 inch knockout which is not large enough for three #6awg wires and a #10 awg ground wire.

Can you confirm there is a conduit coming into the electrical box you want to put the receptacle in? I am curious what it looks like on that side. If it is really conduit but say only 1/2 in then you can't fit the #6 wire in it, but you may be able to do two #8 AWG copper wires and one #10 for ground. Then do a 6-50 receptacle instead of a 14-50 (no neutral needed to avoid wire fill issues). Tesla makes a UMC adapter for this.

#8 is allowed for a 50a circuit when in conduit. I would do #6 AWG if possible, but if only a 1/2 in conduit I would be ok with #8 for such a short run. But if you end up using the Romex not in conduit then you must use #6.

 

[GMan324]

OK, did everyone miss that you can’t use a 50A breaker on a 14-50 outlet. You need a 60A breaker, because you are only allowed to draw 80% load off the breaker. Even if you don’t plan on drawing the full 50A the outlet is rated for it and would have to have the proper size breaker.

 

[eprosenx]

OK, did everyone miss that you can’t use a 50A breaker on a 14-50 outlet. You need a 60A breaker, because you are only allowed to draw 80% load off the breaker. Even if you don’t plan on drawing the full 50A the outlet is rated for it and would have to have the proper size breaker.

This is incorrect.

You absolutely may not put more than a 50a breaker on a 50a receptacle.

You may not put more than 40a of continuous load on a 50a receptacle or 50a breaker (which is 80% of 50a).

EV’s by definition are continuous loads and so that is why any EVSE is limited to 40a on a 14-50 receptacle. The UMC Gen 1 is capable of up to 40a. The Gen 2 which ships with all current Tesla’s is only capable of 32a (so it actually only needs a 40a circuit, though in nearly all cases I would recommend a 50a circuit be installed when installing new).

 

[GMan324]

This is incorrect.

You are right. That’s what I get for posting at 1 AM. I wasn’t thinking about the 80% rule correctly. Thanks for the correction.

 

[NowIsGood]

I just wanted to report back that I successfully completed the installation on Saturday morning, got my car in the afternoon, and gave it a full (90%) charge that night, at 32A/32A. Satisfying! Photos of the completed installation below. Note that I left some slack in the wires in case I change the orientation of the outlet down the road, although I think it looks pretty good as is, with no strain on the outlet or other obvious shock risk, so I’ll likely leave it as is. I haven’t added a faceplate yet, as I discovered the Hubbell requires an extra large opening (2.4688" hole for 2.375" diameter – I ordered a Legrand 302 Stainless Steel Power Outlet Wall Plate from Menards.com). Also, for other DIYer's, the one tool I didn't already have in my arsenal but that I acquired and was very helpful was a high-leverage cable cutter -- I got the Klein tool, in the photos.

Thanks everyone for your help, and specifically:

@Dana1, thank you for your quick initial reply, with succinct answers to each of my questions, which helped me to make good progress. BTW, like you, I’m also now driving a very pretty multi-coat red Model 3.

@Sophias_dad, thanks for pushing me to get the separate wires. I think it was actually a lot easier to run them through the conduit than it would have been to try jam the Romex through. And thanks for your other points of advice, especially the tip to make sure I properly torqued down the wires. I can definitely see how it would be easy to undertighten them and have them pull loose as you muscle things around in the various boxes.

@ksb467, thanks for the reassuring confirmations about using the top panel spot and moving forward with the sideways orientation.

@ewoodrick, thanks for the explanation of the reasoning for the orientation, which actually made me fairly comfortable doing it the “wrong” way (sideways) due to the specific characteristics of my site.

@eprosenx, thanks for the detailed info, including the comment about the quad tandems. I don’t anticipate needing that at my current location, but I have another location where that could be very handy! Regarding the conduit, yes I confirmed at each end that there was metal conduit (flex). The plastic strain relief at top is probably inappropriate for the metal conduit, but didn’t cause any problems I don’t think. I guess the conduit must be 3/4 inch, since I was able to fairly easily fit three 6 gauge wires plus the 10 gauge bare ground. Sorry, I forgot to take a picture from inside the outlet box where the conduit meets before I put everything together.

@GMan324, thanks for chiming in, even if slightly off the mark regarding the application of the 80% rule for the breaker. BTW, in case anyone hasn't seen it, here’s the Tesla specs page for a NEMA 14-50, which includes specification to use a 50A breaker: http://tinyurl.com/y9e3akav

Cheers, all!

 

[eprosenx]

I just wanted to report back that I successfully completed the installation on Saturday morning, got my car in the afternoon, and gave it a full (90%) charge that night, at 32A/32A. Satisfying! Photos of the completed installation below. Note that I left some slack in the wires in case I change the orientation of the outlet down the road, although I think it looks pretty good as is, with no strain on the outlet or other obvious shock risk, so I’ll likely leave it as is. I haven’t added a faceplate yet, as I discovered the Hubbell requires an extra large opening (2.4688" hole for 2.375" diameter – I ordered a Legrand 302 Stainless Steel Power Outlet Wall Plate from Menards.com). Also, for other DIYer's, the one tool I didn't already have in my arsenal but that I acquired and was very helpful was a high-leverage cable cutter -- I got the Klein tool, in the photos.

Thanks everyone for your help, and specifically:

@Dana1, thank you for your quick initial reply, with succinct answers to each of my questions, which helped me to make good progress. BTW, like you, I’m also now driving a very pretty multi-coat red Model 3.

@Sophias_dad, thanks for pushing me to get the separate wires. I think it was actually a lot easier to run them through the conduit than it would have been to try jam the Romex through. And thanks for your other points of advice, especially the tip to make sure I properly torqued down the wires. I can definitely see how it would be easy to undertighten them and have them pull loose as you muscle things around in the various boxes.

@ksb467, thanks for the reassuring confirmations about using the top panel spot and moving forward with the sideways orientation.

@ewoodrick, thanks for the explanation of the reasoning for the orientation, which actually made me fairly comfortable doing it the “wrong” way (sideways) due to the specific characteristics of my site.

@eprosenx, thanks for the detailed info, including the comment about the quad tandems. I don’t anticipate needing that at my current location, but I have another location where that could be very handy! Regarding the conduit, yes I confirmed at each end that there was metal conduit (flex). The plastic strain relief at top is probably inappropriate for the metal conduit, but didn’t cause any problems I don’t think. I guess the conduit must be 3/4 inch, since I was able to fairly easily fit three 6 gauge wires plus the 10 gauge bare ground. Sorry, I forgot to take a picture from inside the outlet box where the conduit meets before I put everything together.

@GMan324, thanks for chiming in, even if slightly off the mark regarding the application of the 80% rule for the breaker. BTW, in case anyone hasn't seen it, here’s the Tesla specs page for a NEMA 14-50, which includes specification to use a 50A breaker: http://tinyurl.com/y9e3akav

Cheers, all!
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I *love* it! Thanks for the detailed report back!

Very nicely done!

For your particular setup I would not worry too much about the receptacle being horizontal. Just be careful! (I am not sure what code actually might say about it)

It feels great to have high speed charging doesn’t it? Nice to have the flexibility!

P.S. Where did you get the 10awg solid conductor wire? I don’t think my Home Depot stocks it...

 

[NowIsGood]

Yes, it's great to start each day with a full tank...er, charge! And sweet to be driving maybe the best car ever made.

I did get the 10awg solid copper bare wire from Home Depot. They sell it by the foot, in Elk Grove, CA anyway.

 

[ksb467]

I just wanted to report back that I successfully completed the installation on Saturday morning, got my car in the afternoon, and gave it a full (90%) charge that night, at 32A/32A. Satisfying! Photos of the completed installation below. Note that I left some slack in the wires in case I change the orientation of the outlet down the road, although I think it looks pretty good as is, with no strain on the outlet or other obvious shock risk, so I’ll likely leave it as is. I haven’t added a faceplate yet, as I discovered the Hubbell requires an extra large opening (2.4688" hole for 2.375" diameter – I ordered a Legrand 302 Stainless Steel Power Outlet Wall Plate from Menards.com). Also, for other DIYer's, the one tool I didn't already have in my arsenal but that I acquired and was very helpful was a high-leverage cable cutter -- I got the Klein tool, in the photos.

Thanks everyone for your help, and specifically:

@Dana1, thank you for your quick initial reply, with succinct answers to each of my questions, which helped me to make good progress. BTW, like you, I’m also now driving a very pretty multi-coat red Model 3.

@Sophias_dad, thanks for pushing me to get the separate wires. I think it was actually a lot easier to run them through the conduit than it would have been to try jam the Romex through. And thanks for your other points of advice, especially the tip to make sure I properly torqued down the wires. I can definitely see how it would be easy to undertighten them and have them pull loose as you muscle things around in the various boxes.

@ksb467, thanks for the reassuring confirmations about using the top panel spot and moving forward with the sideways orientation.

@ewoodrick, thanks for the explanation of the reasoning for the orientation, which actually made me fairly comfortable doing it the “wrong” way (sideways) due to the specific characteristics of my site.

@eprosenx, thanks for the detailed info, including the comment about the quad tandems. I don’t anticipate needing that at my current location, but I have another location where that could be very handy! Regarding the conduit, yes I confirmed at each end that there was metal conduit (flex). The plastic strain relief at top is probably inappropriate for the metal conduit, but didn’t cause any problems I don’t think. I guess the conduit must be 3/4 inch, since I was able to fairly easily fit three 6 gauge wires plus the 10 gauge bare ground. Sorry, I forgot to take a picture from inside the outlet box where the conduit meets before I put everything together.

@GMan324, thanks for chiming in, even if slightly off the mark regarding the application of the 80% rule for the breaker. BTW, in case anyone hasn't seen it, here’s the Tesla specs page for a NEMA 14-50, which includes specification to use a 50A breaker: http://tinyurl.com/y9e3akav

Cheers, all!
View attachment 365333 View attachment 365334 View attachment 365335 View attachment 365336 View attachment 365337 View attachment 365338

Personally, I like the sideways option. It’s always bugged me a bit with it hanging vertically the plug might separate from the charger someday if someone pulls on it the wrong way or gravity wears down the tension between the two over time.