Will my 1950's 240v 6-30 outlet be safe to use?

[JoJa15]

So I discovered I have what looks like a Nema 6-30 plug in my garage. The house was built in the 1950's so I am a little nervous about the wiring.Here are some pics:

So my questions are, is it safe to use a 6-30 outlet? How can I tell if my wire is the proper gauge?

The 6-30 does not have a ground wire. It just has two hots and a neutral. How hard would it be to add a ground and change the outlet to a Nema 14-30? Does having a ground wire add an extra layer of safety?

Right outside of the garage looks to be a ground wire connected to my outside faucet:

Right below the breaker box appears to be that ground wire also connected to a rod in the ground as well as a wire running from the breaker box to that ground rod:

I plan on getting an electrician to look at it but wanted to get peoples thoughts here first before potentially wasting an electricians time.

Thanks in advance for any help provided!

 

[mswlogo]

That’s a 10-30 outlet not a 6-30

10-30 has no ground, just neutral and no longer allowed for new installations.

What you want is a 6-30 or 6-30R (two hots and a ground) but oddly enough Tesla only supports 14-30 (two hots, neutral and ground). But Tesla’s don’t use the neutral !!

That wiring looks rough. Any good electrician will want to replace.

Your safest bet is NO OUTLET. Hard wire a Tesla Wall Connector. You can set it to almost any load you want. No GFCI circuit needed ( GFCI is needed for an EV outlet).

Labor wise, it’s not much different. Just the cost of the wall connector. Keep your “mobile” connector mobile, as in your car.

 

[Frank99]

The wire appears to be 10 gauge THWN ( the gauge is printed on the wires). That’s the appropriate gauge for a 30 amp circuit, so that’s good.
Using the copper water line for ground was common, but I don’t think it’s allowed anymore. As long as the connections are good, it’s probably ok.
As mswlogo noted, without a ground you’ll be out of luck using it for charging. Consult with an electrician about how to run a ground. It might be simple, it might require major modifications to the circuit. Hard to tell from here.
I’d give you a 50-50 chance of it being fairly easy to reuse the circuit.

 

[JoJa15]

That’s a 10-30 outlet not a 6-30

10-30 has no ground, just neutral and no longer allowed for new installations.

What you want is a 6-30 or 6-30R (two hots and a ground) but oddly enough Tesla only supports 14-30 (two hots, neutral and ground). But Tesla’s don’t use the neutral !!

That wiring looks rough. Any good electrician will want to replace.

Your safest bet is NO OUTLET. Hard wire a Tesla Wall Connector. You can set it to almost any load you want. No GFCI circuit needed ( GFCI is needed for an EV outlet).

Labor wise, it’s not much different. Just the cost of the wall connector. Keep your “mobile” connector mobile, as in your car.

Thank you for the quick response! Yep, my bad. I meant to say 10-30 not 6-30.
Tesla sells a 10-30 adapter why cannot I use it?

 

[Frank99]

Well, heck, if they provide one you’re Golden. Spend the $35 and you’re good to go.

 

[mswlogo]

Thank you for the quick response! Yep, my bad. I meant to say 10-30 not 6-30.
Tesla sells a 10-30 adapter why cannot I use it?
View attachment 670446

Tesla does have adapters for it.

But your setup really should be done over. Not sure if an electrician is allowed to replace with 10-30. Also you can’t put a GFCI on that which is also required for new work.

It’s just a really bad idea all around using a 10-30.

There are 3rd party 6-30 adapters.

Since it should be required, including 2 hots, neutral and ground will have modest difference in price.

But a wall connector only needs 2 hots and ground.

Again, your best bet is a wall connector. You asked for advice and I gave it.

Get it rewired and use a wall connector.

 

[cali8484]

It's probably better to replace the 10-30 with 6-30 and move the wire from neutral to ground in the main panel.

 

[JoJa15]

Tesla does have adapters for it.

But your setup really should be done over. Not sure if an electrician is allowed to replace with 10-30. Also you can’t put a GFCI on that which is also required for new work.

It’s just a really bad idea all around using a 10-30.

There are 3rd party 6-30 adapters.

Since it should be required, including 2 hots, neutral and ground will have modest difference in price.

But a wall connector only needs 2 hots and ground.

Again, your best bet is a wall connector. You asked for advice and I gave it.

Get it rewired and use a wall connector.

Would it be possible to get a wall connector and then use the existing wires but have the neutral changed to ground? So essentially the electrician would have to do the following:
(1) In the breaker box connect the current neutral wire in the existing 10-30 run to the ground in the breaker box.
(2) Remove the 10-30 outlet.
(3) Install the wall connector using the existing 10-30 wires with the now neutral changed to a ground?

 

[Frank99]

There’s no reason to redo the wiring. It appears to be wired correctly, and likely to code as the code existed when it was wired. Doesn’t meet current code, but that’s true for just about every existing house. An electrician might suggest cleaning up the ground wires, but those apply to every outlet in your house except the 10-30 under discussion here.
The code doesn’t require that you install a GFCI on an existing outlet just because you decided to plug in an EV.
Now, if you decide to make a significant change to the circuit (like removing the outlet and connecting a Wall Connector), all bets are off. It’s likely that all that needs to be done is what you’ve listed, but depending on where you live that may or may not require pulling permits and getting an inspection; your electrician will tell you what the local rules are.

Frankly, if it were me, I’d buy the 10-30 adapter and be happy.

 

[mswlogo]

Would it be possible to get a wall connector and then use the existing wires but have the neutral changed to ground? So essentially the electrician would have to do the following:
(1) In the breaker box connect the current neutral wire in the existing 10-30 run to the ground in the breaker box.
(2) Remove the 10-30 outlet.
(3) Install the wall connector using the existing 10-30 wires with the now neutral changed to a ground?

Yes, if everything was in good condition.

It will be up to your local electrician and inspector on what needs to be replaced though. I really would not use it, as is, even is it “works”.

 

[mswlogo]

There’s no reason to redo the wiring. It appears to be wired correctly, and likely to code as the code existed when it was wired. Doesn’t meet current code, but that’s true for just about every existing house. An electrician might suggest cleaning up the ground wires, but those apply to every outlet in your house except the 10-30 under discussion here.
The code doesn’t require that you install a GFCI on an existing outlet just because you decided to plug in an EV.
Now, if you decide to make a significant change to the circuit (like removing the outlet and connecting a Wall Connector), all bets are off. It’s likely that all that needs to be done is what you’ve listed, but depending on where you live that may or may not require pulling permits and getting an inspection; your electrician will tell you what the local rules are.

Frankly, if it were me, I’d buy the 10-30 adapter and be happy.

Knob and tubing was code once too.

Just because it’s not REQUIRED doesn’t mean it’s a waste of money to upgrade it to code.

That wiring is a disaster waiting to happen. It might not take that much to make it safer. Wire and conduit might be fine. It looks like water / dampness is getting in. That should be corrected. Not a place you want to skip GFCI (not required for wall connector though).

The goal is safety and reliability. Not to save a few dollars.

Why buy a Tesla when you could have bought something cheaper?

EV charging puts the maximum load on a circuit for longer stretches in time than any other appliance. It also does the bulk of its job while you sleep.

You want it 110% correct.

Don’t mess around.

 

[Frank99]

That’s fine; but your argument suggests that OP should rip out the wiring in his entire house and replace it because it doesn’t meet code. After all, AFCI outlets solve a known problem that kill people every year and I’m sure he doesn’t have those in every bedroom. GFCI outlets solve a known problem that kill people every year, and I’m sure his outdoor, bathroom, and kitchen outlets don’t have those. Do you have good reasoning for why a GFCI is more important on an EV outlet than, for example, an AFCI on a bedroom outlet?

As far as water intrusion, he appears to live in the Bay Area. I’m guessing that most or all of his j-boxes have rust on them; that comes from having a 70 year old house in a coastal environment. And the THWN wire is rated to handle damp conditions.

All I’m saying is that his wiring appears to be normal for a 70 year old house, and with the limited view we have of it I don’t see anything of concern for EV charging using a 10-30 adapter. Certainly having an electrician inspect, change the neutral to a ground, and install a $500 Wall Connector is the best approach, although it’s a bit pricey.

 

[roblab]

That’s a 10-30 outlet not a 6-30

10-30 has no ground, just neutral and no longer allowed for new installations.

What you want is a 6-30 or 6-30R (two hots and a ground) but oddly enough Tesla only supports 14-30 (two hots, neutral and ground). But Tesla’s don’t use the neutral !!

That wiring looks rough. Any good electrician will want to replace.

Your safest bet is NO OUTLET. Hard wire a Tesla Wall Connector. You can set it to almost any load you want. No GFCI circuit needed ( GFCI is needed for an EV outlet).

Labor wise, it’s not much different. Just the cost of the wall connector. Keep your “mobile” connector mobile, as in your car.

My experience: I've had a 220 outlet in my garage for a dozen years or more. I've plugged in a RAV4EV charger, then a Tesla mobile connector, then tossed the connector in the car for trips and vacations, then plugged it in again when we got home. Over and over. There is no reason to "keep your mobile connector... in your car". I generally "keep" my mobile connector plugged into my garage outlet. I mean, that's where I use it, where I charge my car.

I see absolutely no reason for wiring in a Tesla Wall Connector when an outlet will work. I disagree that your wiring is insufficient, but I do agree that any electrician would want to replace it, because they're getting paid to think that way. And the comments that there is no ground, only neutral, is silly. Ground and neutral both go to ground.

It sounds like someone wants you to pay an electrician hundreds of dollars just to rewire a new outlet, when your Tesla will charge just fine off of 10-30. Heck, it will charge off of 110 for that matter, except it just takes a lot longer. I'd say that if you have relatively new circuit breakers, properly sized (30 amp), you don't need to worry. Your wires look fine, even though looks mean nothing, rough or smooth. That's why there are circuit breakers, because you can't tell by looks if wiring is sufficient.

 

[ItsNotAboutTheMoney]

It's your money, and also your house and garage.

A key question is how good the circuit is. Given you "discovered" it, you might want it checked out anyway, and then you might want to bite the bullet and get it updated. It might be allowed for you to modify it to a 14-30.

Cheapest electrician-free route is to buy the 10-30 adapter. You could start with charging amperage turned down for a while to make sure you don't see signs of overheating. Then you can gradually increase the amperage to 24A.

If you do use your UMC, leaving it plugged in is a safer option than frequent plugging and unplugging. If you need portability as well, you could get another one, which would also act as a spare in case your home UMC fails.

Notes:
I am not an electrician.
I do not own a Tesla.
I have a Kona EV on a 30A circuit with a hard-wired 24A EVSE.
I also have a Volt PHEV on a 30A with a 14-30 plug 24A EVSE. (Even though the Volt only takes 14-15A).
I already had the 2 30A circuits and went for minimum electrical work combined with charging flexibility..

 

[SmartElectric]

It’s just a really bad idea all around using a 10-30.

On the other hand, my feedback (not advice).
I would ensure
1) the 10-30 receptacle is wired to code and
2) the receptacle pins have solid grip on the Tesla mobile charging cable 10-30 adaptor

My 1920's outbuilding garage had legacy wiring that I upgraded where prudent, including receptacles to modern code.
I implemented a 10-30 receptacle (bought new) because it was important for my garage panel to stick to 24A continuous current draw.

Been charging our 2013 Model S on 10-30 via mobile connector for 100k miles of driving. We avoid unplug/replug, ie, keep the mobile connector permanently plugged into the receptacle. Only in a few rare off-grid camping trips have I brought the mobile connector with us.

The importance of checking the connection of the adaptor pins to the receptacle is key, you should not allow this connection to overheat, the adaptor will warn you of some conditions, but you should verify yourself too.

 

[BogStandard]

Based on the level of corrosion in the box, I'd at least pull off the wire nuts to see if the wire has any significant tarnish. Strip it back a bit to see how shiny the copper is. I'd then replace the receptacle with a new one at least just in case, they're pretty cheap. Intermittent usage from a dryer or welder may not be a problem there, but a continuous 24 amp draw for potentially several hours may cause some issues.
If it were me, you have the benefit of conduit, it would be super easy and cheap (pandemic wire prices are bit high at the moment though) to just fish new wire with a ground and slap in a 6-30 receptacle with 10ga THHN wire or upgrade to a 6-50 with 8ga wire if you didn't want to hardwire an EVSE.
Be sure to use a torque wrench on all terminals, it's much tighter than you think it is. The 50amp breaker lugs were tighter at specified torque than I could get by using a hand screwdriver.

I ran new conduit and 8ga wire to a disconnect switch, then to a 6-50 receptacle in my garage. I only had to run ~25ft, but it all cost me $130, including the 50A GFCI breaker. I was updating some other circuits in the garage so I guess you could add part of the $60 permit fee too. I put a disconnect out there in case I want to change the receptacle into a hardwired EVSE, in which case I can remove the GFCI breaker if it ever gives me issues.

Note: I'm not an electrician, but it is a hobby of mine that I take seriously and I do keep up on codes as best I can (we're on the 2020 NEC in MN) and have done several major electrical projects on my home and for friends/family with very little, if any, corrective action items from the AHJ. One of them even asked me if I was an electrician one day...

 

[MN-MS100D]

The rust and corrosion is a problem, probably indicates water intrusion. The bigger problem I see in the pictures is the electricians tape wrapped around the hot conductor. Clearly, the insulation was compromised. Replace the surface box, pull new wires, and charge with confidence.

Edit: the grounded conductor is taped, not a phase conductor. It still indicates an insulation issue, though.

 

[Earl]

Clearly, to be on the safe side, you should check the connections.
The wiring part in the pix don't look too bad. I probably wouldn't worry about it - but sometimes folks are better off doing what I say, not what I do
The idea of starting at maybe 16 amps, and looking for signs of heating before bringing it up might be prudent.

 

[RayK]

So I discovered I have what looks like a Nema 6-30 plug in my garage. The house was built in the 1950's so I am a little nervous about the wiring.Here are some pics: View attachment 670438

Thank you for the quick response! Yep, my bad. I meant to say 10-30 not 6-30.
Tesla sells a 10-30 adapter why cannot I use it?
View attachment 670446

@JoJa15 Just in case you decide to use the existing outlet and obtain a 10-30 NEMA Tesla UMC adapter, you'll notice that when you plug in, the outlet is currently install upside-down (in relation to how the Tesla adapter is designed). I'm also assuming that your photo of the outlet is right-side up. While you are at it, you should probably install a new 10-30 commercial/industrial grade outlet (as opposed to residential). Those are of better/higher quality and should stand up to many insert-removal cycles.

 

[JoJa15]

@JoJa15 Just in case you decide to use the existing outlet and obtain a 10-30 NEMA Tesla UMC adapter, you'll notice that when you plug in, the outlet is currently install upside-down (in relation to how the Tesla adapter is designed). I'm also assuming that your photo of the outlet is right-side up. While you are at it, you should probably install a new 10-30 commercial/industrial grade outlet (as opposed to residential). Those are of better/higher quality and should stand up to many insert-removal cycles.

Yep I had already bought a Hubble Industrial grade nema 10-30 to be safe.

I talked with an electrician friend and his main concern was the age of the wire. The house had been built in the 1950's. We don't know (I still need to check) if the wire runs through conduit, in the walls or under the house. I have only been in the house for 5 years but apparently there was a problem with rats before so a rat could have chewed on the wires. He suggested running new cable. If we do that I am going to just run cable/ground for the wall charger, and change the breaker to a 60 amp (if the box is able to handle a 60 amp breaker). That way everything should be perfectly safe and can charge at the fastest rate.