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EVSE adapters

Yes, existing for RV trailer use. I have since purchased a motorhome that is 50amp and use a 30amp adapter to plug into 30amp. Now that I am looking around to much, could I purchase the Tesla 14-50 adapter and use my 50 to 30 to plug into the 30 amp at garage? Hope I said that right! Tesla adapter is $45 and EVSE is $75 or don’t be a cheap azz and buy the EVSE
 

swaltner

Active Member
Oct 13, 2012
1,809
2,087
Kansas, USA
In general, the response to this question is that it’s safer to use the more expensive 30 amp adapter for your outlet.

The problem with using a TT-30 plug to 14-50 receptacle adapter and then a Tesla 14-50 plug on the EVSE is that the EVSE thinks it’s plugged into a 50 amp outlet and could overload the 30 amp circuit. For continuous loads (EV charging), you are only allowed to draw 24 amps on a 30 amp outlet. Tesla’s portable EVSE with a 14-50 plug would try to charge at 32 amps, which is a fire hazard. You can turn the amperage down, which is great until your car forgets and resets the amperage to 32 amps. You can keep an eye on that yourself, but what if it resets sometime that your spouse, child, whoever plugs in and they forget to verify the lower amperage.

You also run into a problem with many of the RV “dogbones” to convert the 30 amp RV outlet into a 50 amp RV outlet. They are not wired for EV charging and yield 0 Volts across the pins that should be 240 Volts.

It’s much easier to spend the extra $40 on one of the $75 adapters you reference and never have to worry about it working safely.

Be aware that a TT-30 outlet is only 120 Volts, so your charging rate will be half what it would be on a 240 Volt 30 Amp outlet.
 

Rocky_H

Well-Known Member
Feb 19, 2015
8,607
11,183
Boise, ID
OP:
Knowing that you have a '30 Amp' circuit is good, but not enough to be safe. You also have to know
1. 120 or 240 volts
2. How many wires
3. Wiring of ground and/or neutral
Jeez, don't be like that. That's all known and specified already:
I have 2 30amp RV receptacles
That is TT-30
1. It's 120V
2. It's three wires
3. It's hot, neutral, and ground

Anyway, @Hoffbrew yes, I have several of the adapters from the EVSEAdapters company, and they are fantastic and very well made. And @swaltner covered the issues in a lot of detail there. Using any kind of plug adapter things that are made for camping or RV use won't work for adapting the TT-30 to 14-50 for electric car charging because they aren't wired in the way the car needs. The EVSEAdapter ones are great and made to do exactly what is needed.

And that's interesting to see that AC Works is finally making real-ish Tesla-style adapter plugs like that, which connect into the UMC and signal the amp limit I presume. They used to just sell those TT-30 to 14-50 outlet converter types, where you would have to use your Tesla 14-50 plug and remember to dial down the amps from the car--not a very good way to go.
 
Has anyone used their adapters? Looking at the TT-30 adapter. I have 2 30amp RV receptacles at home and 1 is mounted on side of garage, next to where the Y will park. I have tried to contact EVSE with no luck to confirm correct adapter. Is there another company that provides same product?

TT-30 Adapter for Tesla Model S/X/3/Y Gen 2 – EVSE Adapters

They also sell the adapter on Amazon.

Another thought, if you don't use the circuit for an RV, if you have the panel space, you could convert to a 240V circuit and get a 6-30 adapter from that same company. Even the 6-20 adapter from Tesla would get you faster charging, if you wanted to stay OEM. Check with an Electrician for local regulations.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
8,607
11,183
Boise, ID
I wasn't taking '30 Amp RV' as well defined, but you could easily know better than me.
That's leaning more toward the terminology of campground employee kind of people. If you try to ask something using NEMA outlet names or say 14-50 or TT-30, you will just get blank stares, and they will have no clue what you are talking about. But their simplified names are consistent and specific.
If a camping site says:
"30A", it means a TT-30
"50A", it means a 14-50
So it is a known thing, but it's different wording than we're used to seeing here.
 
I have all the Tesla adapters, which includes a 14-30, so I just got a TT-30 to 14-30 adapter which I assume the Tesla mobile connector will recognize properly (since it'll be using the 14-30 plug) as a 30A max connection automatically. Unfortunately, I haven't had a chance to test it yet.
 

miimura

Well-Known Member
Aug 21, 2013
7,399
7,404
Los Altos, CA
I have all the Tesla adapters, which includes a 14-30, so I just got a TT-30 to 14-30 adapter which I assume the Tesla mobile connector will recognize properly (since it'll be using the 14-30 plug) as a 30A max connection automatically. Unfortunately, I haven't had a chance to test it yet.
As long as the Neutral from the TT-30 goes to the other hot blade and not the Neutral blade on the 14-30, it will work. This is very specific to Tesla usage of a TT-30 and is nonsensical for RVs and other uses. An RV adapter for 14-30 or 14-50 would distribute the hot line L1 from the TT-30 to both hot lines on the 14-series plug. The Neutral on a Tesla 14-series plug adapter is not connected to anything.
 
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Rocky_H

Well-Known Member
Feb 19, 2015
8,607
11,183
Boise, ID
I have all the Tesla adapters, which includes a 14-30, so I just got a TT-30 to 14-30 adapter which I assume the Tesla mobile connector will recognize properly
1. If you bought it from a camping/RV supply kind of place, it definitely will not work.
2. If you bought a special one that says it is made specifically for electric vehicle charging, it will work.

As @miimura explained, they are wired differently. If you get one of those standard camping supply ones, it won't damage anything, but the car will just see 0V and do nothing.
 
As long as the Neutral from the TT-30 goes to the other hot blade and not the Neutral blade on the 14-30, it will work. This is very specific to Tesla usage of a TT-30 and is nonsensical for RVs and other uses. An RV adapter for 14-30 or 14-50 would distribute the hot line L1 from the TT-30 to both hot lines on the 14-series plug. The Neutral on a Tesla 14-series plug adapter is not connected to anything.

1. If you bought it from a camping/RV supply kind of place, it definitely will not work.
2. If you bought a special one that says it is made specifically for electric vehicle charging, it will work.

As @miimura explained, they are wired differently. If you get one of those standard camping supply ones, it won't damage anything, but the car will just see 0V and do nothing.

Yes, I looked up an adapter that specifically mentioned Tesla compatibility: https://www.amazon.com/gp/product/B07XNPHXV2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8

Mine is the same brand, but has a small cord and isn't just a single, double-sided plug. It seems they switched to this version after my order.

EDIT: Actually, that's not the same product at all. Maybe mine is discontinued. Amazon is interesting like that. My product was, "ONETAK NEMA TT-30P to 14-30R 120V 30 Amp 3 Prong Male Plug to 4 Prong Female Receptacle EV Charger Compatible Tesla Power Cord Adapter Connector"
 
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Yes, I looked up an adapter that specifically mentioned Tesla compatibility: Amazon.com

Mine is the same brand, but has a small cord and isn't just a single, double-sided plug. It seems they switched to this version after my order.

EDIT: Actually, that's not the same product at all. Maybe mine is discontinued. Amazon is interesting like that. My product was, "ONETAK NEMA TT-30P to 14-30R 120V 30 Amp 3 Prong Male Plug to 4 Prong Female Receptacle EV Charger Compatible Tesla Power Cord Adapter Connector"
What you have listed is 120v thus it will be ~ 1/2 speed in terms of charging.

To get full speed out of a 240v 30 amp 14-30 or L14-30 (depending on what you have take a look at the following links):
Tesla will sell you a 14-30r adapter: Gen 2 NEMA Adapters
You can also get a L14-30 to 14-30 adapter:
If you want to skip the adapter ou can get a L14-30 cable that fits the Telsa evse directly: L14-30 Twist-lock Adapter for Tesla Model S/X/3/Y Gen 2 – EVSE Adapters
 
What you have listed is 120v thus it will be ~ 1/2 speed in terms of charging.

To get full speed out of a 240v 30 amp 14-30 or L14-30 (depending on what you have take a look at the following links):
Tesla will sell you a 14-30r adapter: Gen 2 NEMA Adapters
You can also get a L14-30 to 14-30 adapter:
If you want to skip the adapter ou can get a L14-30 cable that fits the Telsa evse directly: L14-30 Twist-lock Adapter for Tesla Model S/X/3/Y Gen 2 – EVSE Adapters

The Amazon listing changed, so the product you're looking at there is not what I have. What I got is a TT-30 to 14-30 adapter. I already have the Tesla 14-30 adapter. I just wanted to be able to plug into TT-30.
 

SageBrush

REJECT Fascism
May 7, 2015
13,758
18,996
New Mexico
Lower voltage should not be a problem. The mobile connector handles 120v just fine. I'm not sure since I haven't used it yet, but I don't see why it would be dangerous to put less than the rated power through the 14-30 adapter.
I don't understand the wiring of the adapter you bought to say one way or another but your reasoning is not inspiring confidence. '120v' is is one hot wire referenced to neutral. '240v' is two hot wires, each 120v to a common neutral, 180 degrees out phase with each other. The Tesla EVSE is flexible in part because the adapter signals the EVSE what to expect. In your config, the EVSE is expecting two hot, out of phase, inputs while the TT-30 receptacle is providing something different.
 

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