Dual TT-30 to 14-50 Charging

[pmbassett]

I will be visiting a campground which I may have access to two TT-30 outlets (on separate non-GFI breakers). Has anyone used or know if a basic Y splitter 2xTT-30 to 14-50 adapter would be supported by the Rivian mobile charger if I were to ensure the two legs are opposite phase?

Obviously I would limit my current to 24A or less

Example Adapter

Sponsored

 

[Dark-Fx]

Do I have to ensure that the two breakers are opposite phases?

With this adapter? Yes. If they aren't on opposite phases, you'll measure ~ 0V across hots, and it simply won't work.

If they are on opposite phases, the circuits have to NOT have ground fault protection on them, or they will fault out. If it's TT-30, odds are you won't have to worry about that. You will have to tell the truck to limit to 24A using the included portable.

If they are on the same phase, you could technically combine them and charge at 48A@120V, but you'd need a much different setup, and I would be monitoring current to make sure neither side goes much over 24A. If you don't know what you are doing, I wouldn't recommend this approach at all.

 

[stewart]

With this adapter? Yes. If they aren't on opposite phases, you'll measure ~ 0V across hots, and it simply won't work.

If they are on opposite phases, the circuits have to NOT have ground fault protection on them, or they will fault out. If it's TT-30, odds are you won't have to worry about that. You will have to tell the truck to limit to 24A using the included portable.

If they are on the same phase, you could technically combine them and charge at 48A@120V, but you'd need a much different setup, and I would be monitoring current to make sure neither side goes much over 24A. If you don't know what you are doing, I wouldn't recommend this approach at all.

I agree. This would not be a good approach even if you know what you are doing.

 

[Supratachophobia]

Personally, having used a TT-30 adapter several times and knowing what I know about the average campsite's electrical capabilities, I wouldn't attempt to press my luck. Please consider sticking with just one adapter.

 

[Cosmacelf]

If the two 30A receptacles are on different phases, then this might work. I say might because there are fault conditions, or the use of a GFCI, which would make this not work. If you are charging overnight, chances are you don’t need to do this, just get an adapter for a single TT-30 to a 14-50.

 

[SPITmadFIRE]

Is the risk really worth it here? I understand how being able to double your charge rate would be cool, but the sheer risk of getting this wrong feels like a huge deal breaker.

 

[SwampNut]

Is the risk really worth it here? I understand how being able to double your charge rate would be cool, but the sheer risk of getting this wrong feels like a huge deal breaker.

Minimal risk, and well worth it if needed. I built my own, but yeah, this adapter would work if phases are correct.

 

[Mathme]

I say get one adapter, set the truck, to charge at 24a overnight, and call it good.

While charging at home on a 40a circuit, I get about 9.3 kWh/hour on a pretty consistent basis. On a 24a circuit (60% of a 40a circuit) at a campground, you should get about 5.6 kWh/hour. At 2 miles/kWh, that gets you about 11 miles range per hour. At that rate, you can easily add 130ish miles in a 12-hour period.

 

[beatle]

If the two 30A receptacles are on different phases, then this might work. I say might because there are fault conditions, or the use of a GFCI, which would make this not work. If you are charging overnight, chances are you don’t need to do this, just get an adapter for a single TT-30 to a 14-50.

Do you know if the truck will accept an adapted TT-30 >> 14-50? I ask because I tried this with my Model S and it refused to charge - possibly because it saw 120v on what it thought was going to be a 240v connection. I charged fine on a TT-30 >> 5-15 adapter, however.

 

[Dark-Fx]

I say get one adapter, set the truck, to charge at 24a overnight, and call it good.

While charging at home on a 40a circuit, I get about 9.3 kWh/hour on a pretty consistent basis. On a 24a circuit (60% of a 40a circuit) at a campground, you should get about 5.6 kWh/hour. At 2 miles/kWh, that gets you about 11 miles range per hour. At that rate, you can easily add 130ish miles in a 12-hour period.

TT-30 is only 120V.

 

[SPITmadFIRE]

I say get one adapter, set the truck, to charge at 24a overnight, and call it good.

While charging at home on a 40a circuit, I get about 9.3 kWh/hour on a pretty consistent basis. On a 24a circuit (60% of a 40a circuit) at a campground, you should get about 5.6 kWh/hour. At 2 miles/kWh, that gets you about 11 miles range per hour. At that rate, you can easily add 130ish miles in a 12-hour period.

TT-30 is 120V so you'd only get 2.8kW assuming zero charging overhead. Realistically, there will always be significant overhead when AC charging so expect closer to 2kW

 

[kingofheaven]

Do you know if the truck will accept an adapted TT-30 >> 14-50? I ask because I tried this with my Model S and it refused to charge - possibly because it saw 120v on what it thought was going to be a 240v connection. I charged fine on a TT-30 >> 5-15 adapter, however.

I have just done this with an adapter I got from amazon, and it worked. first one that I bought didn't work, so I can post a link to the one that actually worked but Not sure if I'm allowed to place links here?

 

[beatle]

The TT-30 >> 5-15 adapter I used was actually provided by the campground, but I'd think they are all the same.

 

[SPITmadFIRE]

The TT-30 >> 5-15 adapter I used was actually provided by the campground, but I'd think they are all the same.

You shouldn't use a 5-15 adapter for TT-30. While 5-15 is a 120V plug, it maxes out at 15A. You want a TT-30 to 14-50 that's meant for EV charging specifically. If you get one designed for EV charging it'll work as expected if you limit your charging to 24A (80% of 30A).

 

[Riviot]

On a 24a circuit (60% of a 40a circuit) at a campground, you should get about 5.6 kWh/hour.

As others said, TT-30 is 125v. So half that. I'm disappointed in your math, and I think your math ancestors are too.

Do you know if the truck will accept an adapted TT-30 >> 14-50? I ask because I tried this with my Model S and it refused to charge - possibly because it saw 120v on what it thought was going to be a 240v connection. I charged fine on a TT-30 >> 5-15 adapter, however.

Not all adapters are wired the same, and for EVs, it matters. You want this one: https://a.co/d/0bw83Vup

https://www.summet.com/blog/2021/04...-from-this-weird-outlet-i-found-in-my-garage/

I have just done this with an adapter I got from amazon, and it worked. first one that I bought didn't work, so I can post a link to the one that actually worked but Not sure if I'm allowed to place links here?

See above

Sponsored