Confusing outlet vs breaker

[Newtothis]

Can anyone think of any reason why my house would be wired with a 50amp breaker to a nema 10-30 outlet? I’m not sure why they didn’t do a 14-50 outlet.

I’m having a few electricians come out for a quote but it’s going to be a few days. My goal is to swap out the outlet and hardwire a Tesla hpwc. Hopefully the wiring is the correct kind otherwise I give up

 

[LoudMusic]

Sounds like they used what they could find and never fixed it. Are you sure it's NEMA 10-30 ? Looks like that was depreciated in 1996(ish) ?

NEMA connector - Wikipedia

en.wikipedia.org

The wire is the important part, especially if you're ditching the outlet anyway. The electrician should be able to tell you what the maximum current is for the existing wire, and you can set your wall connector to that. They will also need to ensure the breaker is correct for that wire.

Don't give up! You're so close!

 

[Newtothis]

Sounds like they used what they could find and never fixed it. Are you sure it's NEMA 10-30 ? Looks like that was depreciated in 1996(ish) ?

NEMA connector - Wikipedia

en.wikipedia.org

The wire is the important part, especially if you're ditching the outlet anyway. The electrician should be able to tell you what the maximum current is for the existing wire, and you can set your wall connector to that. They will also need to ensure the breaker is correct for that wire.

Don't give up! You're so close!

Yeah I had my doubts as well about the outlet because the house was built in 2018ish. But I looked it up and bought the 10-30 adapter from Tesla and it works.

 

[LoudMusic]

Yeah I had my doubts as well about the outlet because the house was built in 2018ish. But I looked it up and bought the 10-30 adapter from Tesla and it works.

Yep, definitely says 10-30 on it.

Keep us updated on what the electrician says.

 

[ucmndd]

Whoever did this either had no clue or no care what they were doing, probably both.

 

[Newtothis]

More things to think about. The NEMA 10-30 is hot/hot/neutral while the HPWC needs hot/hot/ground. In my receptacle I only have 2 hots and a neutral, no ground wire. So…how do I make this work? I cant even swap out for a NEMA 14-50, presuming the wire gauge is correct. Gotten a few quotes, now just waiting for someone to come out and see what’s going on…

Also makes me wonder how the mobile connector does it, because I thought it always needed the ground connector which clearly is not the case here?

Talked to the owner, he said they had it installed around 2018, and their EVSE used a 10-30 which is why they have that.

 

[jcanoe]

The simplest solution: replace the incorrect 50A circuit breaker with a 30A; confirm that the wiring is correct, tight. Purchase the Tesla NEMA 10-30 power plug adapter and use the Tesla Gen2 Mobile Connector when charging your Tesla Model Y.

The best solution: pull new wire, install a 50A or 60A circuit breaker and hard wire the Tesla Gen2 Wall Connector.

By code the ground connection wiring and the neutral connection wiring are connected at only one location; at the service panel.

 

[Newtothis]

The simplest solution: replace the incorrect 50A circuit breaker with a 30A; confirm that the wiring is correct, tight. Purchase the Tesla NEMA 10-30 power plug adapter and use the Tesla Gen2 Mobile Connector when charging your Tesla Model Y.

The best solution: pull new wire, install a 50A or 60A circuit breaker and hard wire the Tesla Gen2 Wall Connector.

By code the ground connection wiring and the neutral connection wiring are connected at only one location; at the service panel.

In theory could someone use a “white neutral wire”, wire it to the ground bar of the service panel making it now a ground wire in a white sheath and labeling it ground?

 

[Rocky_H]

Yeah, this is an interesting topic.

The NEMA 10-30 is hot/hot/neutral

Yes--correct.

while the HPWC needs hot/hot/ground.

Right, but you shouldn't be using a wall connector plugged into an outlet anyway.

In my receptacle I only have 2 hots and a neutral, no ground wire. So…how do I make this work?

You want to take the 10-30 outlet off and just hardwire the wall connector onto that? That's easily done, and is just a wire marking procedure. That white neutral wire just needs to be marked differently (green or black? I forget which.) at both ends to designate that it is now a ground instead of neutral.

I cant even swap out for a NEMA 14-50, presuming the wire gauge is correct.

Right, the 14-XX type of outlets require four wires, but you only have three. If you want to switch to a different outlet type that is still to code, you could remark that white to ground like I mentioned above, and make this a 6-30 outlet, which is hot, hot, and ground.

Also makes me wonder how the mobile connector does it, because I thought it always needed the ground connector which clearly is not the case here?

Oh, yeah. That's just a bit of hand waving. Neutral is also at 0V, like ground is. The Tesla mobile connector just uses that as if it's the ground, and it doesn't make any difference.

Talked to the owner, he said they had it installed around 2018, and their EVSE used a 10-30 which is why they have that.

Ugh. 10-XX outlets have been forbidden from new installations since 1996, so they shouldn't have done that. There are EVSEs that use 10-30 plugs to be able to plug into existing outlets like that, which people may have, but no one should be installing new 10-30 outlets anymore.

 

[jcanoe]

In theory could someone use a “white neutral wire”, wire it to the ground bar of the service panel making it now a ground wire in a white sheath and labeling it ground?

The color doesn't matter if properly labeled, i.e. as ground. If this is for a dedicated circuit you could repurpose the neutral wire as ground when installing the Tesla Wall Connector. This would require the repurposed neutral wire to be connected to the ground connection at the service panel. If the circuit terminates at a 240V receptacle then the receptacle type would have to be one that does not support the neutral connection since the neutral wire will now be used for the ground connection.

 

[Newtothis]

Thanks for you input! Matched what I’m “researching”. I’m liking the idea of repurposing the neutral for ground, and opens the door to a 6-50 down the line if I move out. I’m really annoyed that this house came with a 10-30.

Just had an electrician come out who unfortunately wasn’t versed in gen 3 hpwc and kept saying to just use the neutral and don’t worry about making it a ground…he said he’s done it a million times but I’m wondering if that was older generation hpwc?

He did mention I have an 8 gauge wire, so I think I’m set for a 50amp breaker, 40amp usage? Ideally would have wanted 6 right?

 

[gfunkdave]

Thanks for you input! Matched what I’m “researching”. I’m liking the idea of repurposing the neutral for ground, and opens the door to a 6-50 down the line if I move out. I’m really annoyed that this house came with a 10-30.

Just had an electrician come out who unfortunately wasn’t versed in gen 3 hpwc and kept saying to just use the neutral and don’t worry about making it a ground…he said he’s done it a million times but I’m wondering if that was older generation hpwc?

He did mention I have an 8 gauge wire, so I think I’m set for a 50amp breaker, 40amp usage? Ideally would have wanted 6 right?

If the breaker for this circuit is in the main panel (i.e., the first panel immediately after your meter) then the neutral bus and ground bus are connected together at that panel and the neutral is effectively a ground. Well, it should always effectively be a ground - that's why pre-1996 code allowed the NEMA 10 series of outlets. The issue is that if there's something wrong with the neutral wiring in your house then neutral can be at an appreciable voltage with respect to ground and present a safety hazard. That's why NEMA 10 is no longer allowed and new construction requires 4-wire outlets. But I digress. If the breaker for this circuit is in a subpanel you will need to open that panel and move the wire from the neutral bus to the ground bus.

Depending on your locale, your local town/county electric code may require you use only bare copper or green wire for ground, and may not allow you to wrap a white neutral in green tape. But electrically they are the same thing.

If you have 8 gauge Romex then you are limited to a max 40A circuit breaker on that circuit. It is permissible to put a 6-50 or 10-50 on that circuit since there are no 40A-rated outlets. If you have separate 8-gauge wires in conduit then you can put a 50A breaker on the circuit.

Your electrician is saying to use the neutral as a ground, which is what you're thinking of doing, except it seems he's saying you don't need to put the green tape on it. I say it's good form to put the tape on (at the panel too, if you're comfortable with it).

 

[Newtothis]

Since I dont see a ground wire, it’s likely they didnt use Romex? It is likely they just individually wired it?

 

[gfunkdave]

Yup, that's loose wire in conduit so you can use a 50A breaker. But the fact that there isn't a ground wire doesn't matter since the NEMA 10 outlet that was there already does not have a ground connection, and they didn't run a ground wire. You can see it's conduit because you can see the threaded conduit connector sticking into the junction box. Also if it were Romex you'd see some of the Romex sheath inside the junction box.

Your locale may also allow you to use the metal conduit as a ground path. Chicago does, for example. If that's the case you can install either a 6-50 or 14-50. A quick way to see if it will work is to use a multimeter to see if there's continuity between the white neutral wire and the metal junction box. But if it were me I might call an electrician to verify, or call your local building inspector to ask if conduit can be a legal grounding means where you are, since it could have safety implications.

If it is, you can usually just install the outlet and it will ground itself through the screws holding it to the box. Or you could get a short length of 10 gauge green or bare wire, screw one end to one of the screw holes in the back of the box, and the other to the ground connector on the outlet.