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30amp RV Charging

supratachophobia

Active Member
Sep 24, 2014
3,858
2,757
Columbus, Ohio
Hey all, I've been trying to get a good answer on this for a couple days. I'm going Tesla-camping and the campground has only the 30amp RV hookups. This is a 30amp @ 110v connector. The highest connector Tesla makes for 110v is 20amps. I'm trying to see if an adapter can be had or made to accomplish this. Here are the facts so far.

This can be purchased:
NEMA 14-50R to TT-30P RV Plug Adapter Cord
It basically plugs into a 30amp campground socket and gives you a NEMA 14-50 to plug into. Then you have to manually dial down the amps to 24 so as not to blow the fuse. My questions on this are, what will the car think when it expects to get 240v but is only getting 110v? And if you can have a NEMA 14-50, why can't you have a plug for a genuine Tesla adapter that is rated for 30amps so you don't have to tell the car to dial it down and risk forgetting? And if you can truly build the latter, how would you wire it up, which hot would you drop going to the receptacle or does it not matter?


The other option is to just build a TT-30 to NEMA 5-20 and be content at 16amps. My only issue with that is to accept defeat when there are potentially 8amps left on the table to take advantage of (if it can be done safely).

Thanks for your input.
 

StaticDischarge

Utterly Unknown....
Mar 25, 2015
56
48
Edmonds, WA
I carry and have used a similar adapter

NEMA 14-50R to TT-30P RV Plug Adapter

It works fine, about 8mph charging. No idea how to answer your actual questions...

The circuit breaker tripped once when a neighboring spot turned on a large amperage appliance. A good idea to figure out if you are sharing the 24A and find the breaker. This particular adapter needs to be propped up to prevent self-unplugging due to the weight of the Tesla gear.
 

TexasEV

Well-Known Member
Jun 5, 2013
7,650
8,911
Austin, TX
Those adapters are fine, but people should beware that many 14-50 to TT-30 adapters marketed for RVs will not work with Teslas. Only buy 14-50 to TT-30 adapters that are labeled for use with Teslas.

The car doesn't care about 240 or 120V, just amps. That's why the 6-20R to 5-20P adapter (also from EVSEadapters) will work to connect a UMC 5-20 adapter to a 240V 20A air conditioning outlet and set the amps properly.
 
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supratachophobia

Active Member
Sep 24, 2014
3,858
2,757
Columbus, Ohio
Great, now I want to make my own. So which hot do I eliminate?

And the "car doesn't care and voltage" comment makes sense as I've seen it do 202v up through 246v, why would 120v be different?

Edit: I should add that I found the difference between the Tesla tt-30 adapter and a traditional adapter. The non Tesla adapters split the available 120v hot to both of the hots in the 14-50 receptacle.
 

Canuck

Well-Known Member
Nov 30, 2013
6,125
5,777
South Surrey, BC
Those adapters are fine, but people should beware that many 14-50 to TT-30 adapters marketed for RVs will not work with Teslas. Only buy 14-50 to TT-30 adapters that are labeled for use with Teslas.

That's true for the plastic molded ones. But you could buy one like InternetDude's in the video above, open it up like he did, and move one wire (which is really easy -- the instructions are even in the video above). That way instead of paying $44 from evseadapeter in the link above, you can get one for $18:

Amazon.com: Conntek RV Adapter TT-30P 30A RV Plug to RV 50A 125/250V Female Connector: Automotive
 
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SPXMike

Member
Oct 1, 2015
110
96
La Habra Heights, CA
Every Electron Pilot should read @FlasherZ's FAQ: Home Tesla charging infrastructure Q&A. Link is in his signature. Tons of excellent info and well maintained. In the first post there is a link to @Cosmacelf's terrific write up on home-made adapters. After reading it I was practically giddy - bought a bunch of connectors from Amazon and wire from Home Depot and had a great MacGyver weekend in my garage! Thank you!
 

Rocky_H

Well-Known Member
Feb 19, 2015
6,801
8,410
Boise, ID
Because of the Tesla charging system not caring about the voltage level, it was really nice to make adapters that just matched the current level. So as @TexasEV mentioned, you could adapt a 6-20 plug to 5-20 receptacle, and then use the car’s official 5-20 adapter, which would properly set the current level when it was plugged in. That was great, safe, and reliable.


So this had things covered when there were official adapters for 5-15, 5-20, 10-30, and 14-50. Those were all of the basic current levels for all of the main outlet types you could find out in the wild. Now, there is an annoying problem. Tesla does not offer ANY official adapter at the 30A level. So there is not a good safe way to make an adapter to TT-30, L6-30, 10-30, or 14-30 outlets that matches the current properly and automatically. With all of those types, that’s quite a lot of charging points that are a little sketchy to use, since Tesla won’t sell a 30A adapter anymore.
 
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supratachophobia

Active Member
Sep 24, 2014
3,858
2,757
Columbus, Ohio
Because of the Tesla charging system not caring about the voltage level, it was really nice to make adapters that just matched the current level. So as @TexasEV mentioned, you could adapt a 6-20 plug to 5-20 receptacle, and then use the car’s official 5-20 adapter, which would properly set the current level when it was plugged in. That was great, safe, and reliable.


So this had things covered when there were official adapters for 5-15, 5-20, 10-30, and 14-50. Those were all of the basic current levels for all of the main outlet types you could find out in the wild. Now, there is an annoying problem. Tesla does not offer ANY official adapter at the 30A level. So there is not a good safe way to make an adapter to TT-30, L6-30, 10-30, or 14-30 outlets that matches the current properly and automatically. With all of those types, that’s quite a lot of charging points that are a little sketchy to use, since Tesla won’t sell a 30A adapter anymore.

I'm going to do a tt-30 to 14-30 adapter. That way it will auto set the amperage safely.
 

MorrisonHiker

Well-Known Member
Mar 8, 2015
10,246
9,980
Colorado
I'm going to do a tt-30 to 14-30 adapter. That way it will auto set the amperage safely.
Didn't Tesla offer a TT-30 UMC adapter years ago or am I remembering things incorrectly? It they did, it would be nice if those were still available at the Service Centers...

Edit:
I must've been remembering incorrectly. I checked the internet archives and found 10-30, 14-30, 6-50, etc. but no TT-30 UMC adapters.
 
Last edited:

supratachophobia

Active Member
Sep 24, 2014
3,858
2,757
Columbus, Ohio
Finished. If someone could check my work.....

Looking at the TT-30 prong/pin side from the front, the angled right prong has the black wire and the angled left plug has the white wire. The rounded prong has the grey/green? wire.

If you are looking at the 14-30 socket side from the front (the one with the holes), the rounded prong hole has the grey/green wire, the straight prong hole on the right has the black wire, and the straight prong hole on the left has the white wire. There is no wire going to the L shaped prong.

All connections have injected silicon, electrical tape, and heat-shrink wrap on them. The TT-30 plug is not strictly water-proof, but where we are, the TT-30 RV connections have the boxes with the flip-up covers that prevent water from landing directly on the outlet/plug when in use. The 14-30 has a place to hook it onto the electrical box, hopefully under the same flip-up cover that protects the outlet.
 

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Cosmacelf

Well-Known Member
Mar 6, 2013
8,777
22,250
San Diego
Finished. If someone could check my work.....

Looking at the TT-30 prong/pin side from the front, the angled right prong has the black wire and the angled left plug has the white wire. The rounded prong has the grey/green? wire.

If you are looking at the 14-30 socket side from the front (the one with the holes), the rounded prong hole has the grey/green wire, the straight prong hole on the right has the black wire, and the straight prong hole on the left has the white wire. There is no wire going to the L shaped prong.

All connections have injected silicon, electrical tape, and heat-shrink wrap on them. The TT-30 plug is not strictly water-proof, but where we are, the TT-30 RV connections have the boxes with the flip-up covers that prevent water from landing directly on the outlet/plug when in use. The 14-30 has a place to hook it onto the electrical box, hopefully under the same flip-up cover that protects the outlet.

No one can tell if this adapter is wired correctly based on your description since you don't tell us where the ground pin is, up or down. Without that knowledge, saying left or right is meaningless since you can turn the plug 180 degrees and now left is right and right is left. So, try again, but this time specify whether the ground pin is on top or bottom when saying what is connected to the left and right pins.

The adapter certainly looks nice...
 

supratachophobia

Active Member
Sep 24, 2014
3,858
2,757
Columbus, Ohio
No one can tell if this adapter is wired correctly based on your description since you don't tell us where the ground pin is, up or down. Without that knowledge, saying left or right is meaningless since you can turn the plug 180 degrees and now left is right and right is left. So, try again, but this time specify whether the ground pin is on top or bottom when saying what is connected to the left and right pins.

The adapter certainly looks nice...

Whoops, makes sense when it's in front of me!

On the plug/pin connector, ground (round pin) is on top. And on the socket side, round ground pin is on top and L shaped connector is in the bottom.
 

supratachophobia

Active Member
Sep 24, 2014
3,858
2,757
Columbus, Ohio
Just curious - why did you go with the box + lid for the 14-50r instead of the Camco 55353?

Three reasons:
1. $14.72 vs. $5.67
2. The Camco 55353 looks to be a 14-50 and I wanted a 14-30 so I would not forget to turn the amperage down.
3. I wanted a cover that could be closed when not in use. You know, for that "it looks like it belongs here" look.
 
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Cosmacelf

Well-Known Member
Mar 6, 2013
8,777
22,250
San Diego
I'm not somewhere where I can write down a diagram, but based on your wiring description, I think you wired it correctly. The TT-30 is tricky since Tesla wants to see the hot and neutral on specific pins for 120v supplies, you can't reverse them.
 

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