NEMA 14-50 UMC Adapter No Longer Included With New Purchases

[Moze1021]

Several thoughts:

1. You should not need the disconnect switch on a receptacle for sure, or even on a Wall Connector. (Unless you are in Canada or somewhere with different rules?) at least not st 60a or below.
2. Does the receptacle option include a GFCI breaker? That cost seems artificially low. GFCI is required by US NEC ok the receptacle, but NOT on the wall connector, so it saves most folks a about $100.
3. If you go the wall connector route it lets you keep the UMC in your car at all times which is a nice feel good safety measure.
4. If you go the wall connector route I would probably want to do a 60a circuit so you could enable a full 48a charge rate if your vehicle supports it. This can be accomplished with 6 gauge wire if it can be used at the 75c rating. So romex does not meet this (due to a code requirement for it to be treated at 60c). SE wire does, MC does, or THHN in any kind of conduit.

I am a massive wall connector fan. You won’t be disappointed.

Thanks! I'm just in PA outside of Philadelphia...so no different rules...

Interestingly, this guy was the only one of the 5 electricians I consulted who said I needed the disconnect, but he was also the cheapest. I guess I figured that the disconnect served the same purpose of the GFCI (which none of the other electricians mentioned at all)...

So I just let it go and figured he knows what he's doing...

I worry about "challenging" the guy at this point, since it's his profession... any advice on how to proceed?

I like the idea of the wall connector but I'm already pretty disappointed that the charger install is as much as it is, so trying to limit spend as much as possible.

 

[eprosenx]

Thanks! I'm just in PA outside of Philadelphia...so no different rules...

Interestingly, this guy was the only one of the 5 electricians I consulted who said I needed the disconnect, but he was also the cheapest. I guess I figured that the disconnect served the same purpose of the GFCI (which none of the other electricians mentioned at all)...

So I just let it go and figured he knows what he's doing...

I worry about "challenging" the guy at this point, since it's his profession... any advice on how to proceed?

I like the idea of the wall connector but I'm already pretty disappointed that the charger install is as much as it is, so trying to limit spend as much as possible.

Hrm, yeah, the disconnect is totally stupid since a receptacle inherently counts as a disconnect (the point of the disconnect is typically so a maintenance tech working on something can easily turn it off and know it is turned off - unplugging it serves this purpose).

To be code compliant the GFCI breaker is requried. (though I personally think it is a stupid requirement if the receptacle is in a dry location like a garage since the EVSE has a built in GFCI)

I personally would install a Wall Connector on a 60a circuit (without a disconnect or GFCI breaker since neither are required), but since you are trying to shave a few bucks, doing it with Romex and a 50a circuit would be perfectly acceptable as well (and still a little faster charge rate than the 14-50 with the UMC). If you really need to shave every buck then just do the 14-50 on the 50a circuit as you planned, but try to convince the electrician to eliminate the disconnect since that is dumb. Perhaps do the GFCI breaker (if not already included in the quote) in lieu of the disconnect since the GFCI is actually what is required by code (though most inspectors don't seem to know this and will pass you without it - also if you install a RV receptacle instead of an EV receptacle the GFCI requirement does not exist - how stupid is that?)


Note that the Wall Connector is itself a cable holder, so that eliminates that as well.

 

[AtlasTracer]

I Iike the idea of the wall connector but I'm already pretty disappointed that the charger install is as much as it is, so trying to limit spend as much as possible.

I'm in a similar situation in Canada. And the significantly faster charge rate (48a vs 32a) with the wall connector has me leaning towards that. Having to buy an adapter all of a sudden is irritating. And while the NEMA outlet is cheaper....I'm thinking the hardwire is the best long term solution. Even if it's a bit more.

Although bottom line is you'll probably still charge the car completely while you are sleeping either way. So go with what you can afford/comfortable with.

 

[tga]

To be code compliant the GFCI breaker is requried.

Only if your community has adopted NEC 2017. Plenty of communities are still on 2014 or even 2011, neither of which have the GFCI requirement.

 

[Moze1021]

Hmm..looks like PA is still on NEC 2014. So that explains why no electricians said I needed GFCI.

Not sure why the one says I need a disconnect

 

[hcdavis3]

Hmm..looks like PA is still on NEC 2014. So that explains why no electricians said I needed GFCI.

Not sure why the one says I need a disconnect

Same with me here in MA MOZE. Both my electrician and the wiring inspector said it’s not required. The inspector asked colleagues from 2 nearby towns and the answer was the same.

 

[eprosenx]

Only if your community has adopted NEC 2017. Plenty of communities are still on 2014 or even 2011, neither of which have the GFCI requirement.

Great callout, my bad for not specifying. Also, some jurisdictions could have adopted 2017 NEC but modified it to strike the requirement.

Same with me here in MA MOZE. Both my electrician and the wiring inspector said it’s not required. The inspector asked colleagues from 2 nearby towns and the answer was the same.

According to this, Massachusetts you should be on 2017 code. You can register for free access on the NFPA site to go look it up. I think it is 625.56. Many inspectors still don't know that section of the code.

Massachusetts Electrical Code

 

[tga]

Great callout, my bad for not specifying. Also, some jurisdictions could have adopted 2017 NEC but modified it to strike the requirement.

I'm only aware of it because my city is still on 2011, so I looked through chapter 625 in 2011, 2014, and 2017

 

[wws]

Indeed, all those NEMA 14-50 adapters are dangerous, as you need to manually limit the current. If you forget to do so, you depend on the breaker tripping as your only defense against overloading the circuit that might cause a fire. Some people use these adapters for plugs that have native adapters from Tesla because they already have the NEMA 14-50 adapter. That may be another factor in the decision not to include it with the UMC anymore.

The evseadapters TT-30 adapter for the v2 UMC, which is the one I have, is built as a proper 30 amp adapter. That is, it tells the UMC to restrict current to 24 amps without requiring any involvement from the user of it. Their other v2 UMC adapters set their respective current limits the same way.

If one has a v1 UMC (and I have one of those too), it is certainly better to adapt to one of the UMC adapters with the correct amperage level than to just generically use a 14-50. Fortunately I have both 30 amp adapters for it. Still need to get a 5-20 for it, but not in a hurry since I have both 5-20 and 6-20 adapters for my v2 UMC.

 

[Moze1021]

Still wavering...

Mentioned to my wife that the Tesla Wall Connector might have safety advantages over the NEMA 14-50/mobile connector option and she was intrigued... But im not completely sure if my statement was even true...so..was it??

To me, pros of Wall Connector:

Faster charging rate
Get to keep UMC in car
Safer?
More reliable?


Pros of 14-50 outlet option:

Cheaper
More versatile if buy a non-Tesla EV in future


Can anyone expand on safety/reliability?

 

[eprosenx]

Still wavering...

Mentioned to my wife that the Tesla Wall Connector might have safety advantages over the NEMA 14-50/mobile connector option and she was intrigued... But im not completely sure if my statement was even true...so..was it??

To me, pros of Wall Connector:

Faster charging rate
Get to keep UMC in car
Safer?
More reliable?


Pros of 14-50 outlet option:

Cheaper
More versatile if buy a non-Tesla EV in future


Can anyone expand on safety/reliability?

So the safety is somewhat comparable since both the wall connector and the UMC have built in GFCI features and they don’t power up the cord to the car until the car is confirmed to be connected. That is the most critical feature set from a safety standpoint.

Now the difference between the UMC and the Wall Connector is that the UMC relies on a plug which is a possible point of failure. We have seen a number of melted receptacles on the forums here.

The other potential concern point is safety when connecting the UMC to the receptacle. It would not be hard to get a finger in and touch a live wire. This is especially concerning if you are plugging it in while in the rain. The latest NEC 2017 code requires all EV receptacles to be GFCI protected. While this enhances safety, there are conflicting opinions as to whether those advantages outweigh the downsides.

These topics are discussed at length on the forums here and so I wrote some of my thoughts down here. It might be good background reading for you:

https://www.article625.com/2019/05/01/how-should-i-charge-my-tesla/

 

[TexasEV]

“Get to keep UMC in the car” isn’t a reason to install a Wall Connector. There is no reason you would need to keep the UMC in the car. Keep it plugged in and hanging on a hook in the garage, and only take it with you when you’re going on a trip. Even then you’re unlikely to use it unless you’re spending the night at someone’s house. The “mobile” in UMC is a capability, not a requirement.

 

[solodogg]

Pros of 14-50 outlet option:

Cheaper
More versatile if buy a non-Tesla EV in future


Can anyone expand on safety/reliability?

Why not do the wall connector now, and if you need something for a non-Tesla EV in the future, you can swap the wall connector with whatever receptacle you need? Once the wires are in place, you can always perform a breaker swap and install a box with a plug in it.

As far as safety/reliability goes, not having a receptacle to wear out with repeated plugging/unplugging is a plus, as well as less chance of electric shock with all wires being fully contained within the wall connector. The wall connector also has the GFCI built in, and i'm quite sure it's more robust than what most breakers include.

 

[TexasEV]

As far as safety/reliability goes, not having a receptacle to wear out with repeated plugging/unplugging is a plus, as well as less chance of electric shock with all wires being fully contained within the wall connector. The wall connector also has the GFCI built in, and i'm quite sure it's more robust than what most breakers include.

As explained above, there is no repeated plugging/unplugging. Maybe a few times per year when going on vacation. The UMC has a GFCI also built in also, no difference from Wall Connector there. There’s no chance of electric shock because it’s a EVSE, just as the Wall Connector is, meaning no current flows unless there’s a proper connection to the car.

 

[solodogg]

As explained above, there is no repeated plugging/unplugging. Maybe a few times per year when going on vacation. The UMC has a GFCI also built in also, no difference from Wall Connector there. There’s no chance of electric shock because it’s a EVSE, just as the Wall Connector is, meaning no current flows unless there’s a proper connection to the car.

You start out by saying no repeated plugging/unplugging, but then describe plugging/unplugging when going on vacation (1 > 0). 14-50 outlets are not designed to have devices added and removed more than a couple of times, they are meant to basically be permanent fixtures. Any plugging/unplugging on these outlets relaxes the jaws that clamp down on the plug, and will eventually cause issues.

Yes, the UMC has a GFCI as well, but if your jurisdiction follows the latest electrical code, your breaker will require it as well. If you use the wall connector, since there is no receptacle involved, no GFCI breaker is required. Longevity and durability aside on the breaker GFCI, Home Depot carries the SquareD QO 50a breaker for $21, but the GFCI breaker is $125. Now, if local requirements do not call for that added breaker protection, that's great!

With ANY electrical circuit, there is always a chance for shock. Don't let downstream handshakes fool you, electricity always takes the path of least resistance. The only thing keeping that EVSE from being energized is a computer circuit waiting for a handshake to be completed, a computer circuit that can fail at any time. Also, adding the receptacle means there is always a chance of the plug being slightly pulled from the wall, which would be susceptible to something falling between the plug and receptacle.

Even with the wall connector, there is always a chance of electric shock, but with everything being fully contained inside the unit, and isolated by a plastic housing, the chances are much less likely than using a metal receptacle with a plug disconnect.

 

[Moze1021]

Why not do the wall connector now, and if you need something for a non-Tesla EV in the future, you can swap the wall connector with whatever receptacle you need? Once the wires are in place, you can always perform a breaker swap and install a box with a plug in it.

As far as safety/reliability goes, not having a receptacle to wear out with repeated plugging/unplugging is a plus, as well as less chance of electric shock with all wires being fully contained within the wall connector. The wall connector also has the GFCI built in, and i'm quite sure it's more robust than what most breakers include.

I mean biggest reason for not doing now is the extra cost..already getting lot of leeway from my wife being cool with me getting a Tesla..

Also I don't have to have a GFCI in my area.. so that's not a cost savings for me..

 

[solodogg]

I mean biggest reason for not doing now is the extra cost..already getting lot of leeway from my wife being cool with me getting a Tesla..

Also I don't have to have a GFCI in my area.. so that's not a cost savings for me..

If cost is the main factor, then definitely go 14-50. But if you ever plan on getting a second UMC to keep in the car in the future, a wall connector becomes the better option at that point.

 

[TexasEV]

You start out by saying no repeated plugging/unplugging, but then describe plugging/unplugging when going on vacation (1 > 0). 14-50 outlets are not designed to have devices added and removed more than a couple of times, they are meant to basically be permanent fixtures.

So RV parks shouldn’t have 14-50 outlets? RVs plug and unplug an order of magnitude more often than a Tesla owner does when doing it a few times/ year.

By repeated I mean taking the UMC with you most every time you drive. That’s not how a UMC needs to be used for home charging. Tens of thousands of Tesla owners have used the UMC for home charging since 2013 as I’ve described, just taking it on vacations, and it’s worked just fine. Even if the outlet needs to be replaced after many years, it’s still less expensive than buying a Wall Connector.

 

[solodogg]

So RV parks shouldn’t have 14-50 outlets? RVs plug and unplug an order of magnitude more often than a Tesla owner does when doing it a few times/ year.

By repeated I mean taking the UMC with you most every time you drive. That’s not how a UMC needs to be used for home charging. Tens of thousands of Tesla owners have used the UMC for home charging since 2013 as I’ve described, just taking it on vacations, and it’s worked just fine. Even if the outlet needs to be replaced after many years, it’s still less expensive than buying a Wall Connector.

Never argued that it's not a good solution, just arguing that the wall connector is a better and more reliable solution. Just because something can be done doesn't mean it's the best way.

Also, while likely not used in most RV parks, there are commercial grade 14-50 receptacles that can be used to minimize issues with the constant plugging/unplugging. Most homeowners aren't going to spend the money on commercial grade parts, and most electricians aren't going to quote high quality parts because they know their pricing has to be competitive.

For me, it's better to have the wall connector at home, and keep the UMC with me for charging at work, so it has advantages. Just trying to give a different point of view for others to consider.

 

[TexasEV]

Also, while likely not used in most RV parks, there are commercial grade 14-50 receptacles that can be used to minimize issues with the constant plugging/unplugging. Most homeowners aren't going to spend the money on commercial grade parts, and most electricians aren't going to quote high quality parts because they know their pricing has to be competitive.

Actually Tesla's installation instructions do recommend using a "high quality, industrial grade outlet", and until this year the previous versions listed two examples by brand and part number. That was useful-- I don't know why Tesla stopped doing that. Specifying commercial grade outlets for the installations has been discussed countless times here over the years. I would hope that most electricians recommended by Tesla, and others with experience in installing outlets for EV charging, would quote those.

https://www.tesla.com/sites/default/files/pdfs/installation-guides/nema-14-50-installation-guide.pdf