Combining 2 TT-30 outlets to a 14-50R?

[VinceGlorioso]

Has anyone made up an article to combine two TT-30 outlets (assuming the two 120 volt hots) into a single 14-50R receptacle?

I am looking to charge at 240V, 24 amps at a place that has these pedestals with TT-30 outlets ... and I am trying to keep my research low profile. I bought 2 TT-30 plugs from the local campground supply store and I will wire one each hot onto opposing hot wire sides (X and Y) of a 14-50 receptacle and either combine or ignore the neutrals. I am pretty sure this place has just split-phase power, but I'll get what I can get, 208 is better than 120 at 12 amps.

I'll be using the newer portable EVSE with my 2018 Leaf S, does anyone know if it will limit current to 24A?

I want to hear from anyone with experience in doing this.

 

[Learjet]

have you checked to make sure the 30 amp outlets are not on the same phase?

 

[VinceGlorioso]

Mr. Learjet,

No, I haven't ... the place where I want to charge is far away, it's all day to go up and back. I am trying to be low profile about this and I haven't checked that, yet. The less questions I ask of the staff there, the better.

Vince

 

[Oilpan4]

Might want to test to see if those 120v hots are on opposing phases before spending more money.
"208v" will show around 220v and as much as much as 234 volts on a meter.
Actual single phase 240v will show between 240 to 250v.

 

[smkettner]

The pre-made adapter is $22 on Amazon. Add a 30a extension if needed and away you go.

https://www.amazon.com/ABN-Adapter-...onverter/dp/B0756QF5WL/ref=asc_df_B0756QF5WL/

User adjustable EVSE:

https://www.evseadapters.com/produc...120-240v-charger-evse/?variant=14295581458530

 

[wwhitney]

The pre-made adapter is $22 on Amazon. Add a 30a extension if needed and away you go.

https://www.amazon.com/ABN-Adapter-...onverter/dp/B0756QF5WL/ref=asc_df_B0756QF5WL/

That product presents an unsafe risk of shock and is illegal.

Cheers, Wayne

 

[smkettner]

Because of a potentially exposed neutral and ground wire?

 

[91040]

Because one TT-30 could be plugged in while the other one wasn’t. The exposed plug would be live.

 

[wwhitney]

Because one TT-30 could be plugged in while the other one wasn’t. The exposed plug would be live.

When the load is also connected to the receptacle end. The unplugged plug is then energized through the load from the plugged-in plug.

Cheers, Wayne

 

[VinceGlorioso]

Thank you for clueing me in to the adapter on Amazon. I put in an order and hopefully it will be here in 2 weeks.

As far as the electrocution hazard:
a. Thanks for letting me know.
b. I suspect that the EVSE would go into fault and shutdown the load (i.e. the charger in the car) if I lost voltage on one of the hots.
c. If it's wired the way I think, the hot on one wire should not be connected to the other hot wire.
d. is for Darwin

And I did take back the $34 worth of RR-30 replacement plugs to Outdoor World.
I'll post an update next month.
Vince

 

[jjeff]

Has anyone made up an article to combine two TT-30 outlets (assuming the two 120 volt hots) into a single 14-50R receptacle?

I am looking to charge at 240V, 24 amps at a place that has these pedestals with TT-30 outlets ... and I am trying to keep my research low profile. I bought 2 TT-30 plugs from the local campground supply store and I will wire one each hot onto opposing hot wire sides (X and Y) of a 14-50 receptacle and either combine or ignore the neutrals. I am pretty sure this place has just split-phase power, but I'll get what I can get, 208 is better than 120 at 12 amps.

I'll be using the newer portable EVSE with my 2018 Leaf S, does anyone know if it will limit current to 24A?

I want to hear from anyone with experience in doing this.

If you mean the 240v L2 EVSE that comes with some Leafs, no. It will draw around 27.5a and probably overheat a TT-30 circuit which is 30 but only 24a continuous and as many circuits at campgrounds are older and of dubious quality, I personally would be a little leary at pulling even 24a continuous, let alone the 27.5a the OEM Leaf EVSE can pull. I kind of think that the adapter is a nice idea, albeit potentially dangerous but I'd really look for an EVSE you could set the maximum current to 20a or 24a max if you monitor things for overheating.
It looks like the linked adjustable EVSE lacks a 20a setting so if setting to 24a I'd really monitor things and as you won't have access to the breaker panel you won't really have a way to monitor the actual breaker which could get rather warm at 24a continuous. Many Juicebox EVSEs allows you to adjust the amperage in 1a increments but require a cell phone and internet service and are several hundred dollars more than the EVSE linked.

 

[smkettner]

Most 30 amp RV parks are wired on a 200 or 400 amp loop with 30 amp breaker at the pedestal. 24 amps continuous should present no issue. Although many connectors are old, worn, pitted and corroded so do check the plug for heat at 30 minutes.

 

[jjeff]

Most 30 amp RV parks are wired on a 200 or 400 amp loop with 30 amp breaker at the pedestal. 24 amps continuous should present no issue. Although many connectors are old, worn, pitted and corroded so do check the plug for heat at 30 minutes.

Interesting, in that case after 30 minutes feeling the pedestal breaker(with the back of your finger) and after unplugging both TT-30 plugs and feeling those, should give the OP a good feel of things. I have to admit, your loop statement makes much more sense than my homerun idea where each pedestal/breaker would have a corresponding 30a breaker in a main panel.

 

[GerryAZ]

Vince,

If your 2018 S came with the Nissan dual-voltage portable EVSE like my 2019 SL Plus (with 14-50P plug and 5-15P adapter), then it will not work if the voltage on the 240-volt circuit drops too much. It will not work on the nominal 208-volt circuit at my workshop/garage which normally runs about 212 when charging my car at 30 amperes using my Clipper Creek EVSE. I tried the portable Nissan EVSE at my workshop--it powered up and appeared ready to charge, but shutdown with lights indicating errors as soon as the car ramped up charging current. Therefore, I suspect that it will shutdown if the voltage drops about 10% (240-24=216) below nominal of 240. The Nissan portable unit is not adjustable and the car will draw a full 30 amperes if the voltage drops below 240 (about 27.5 A at 240 V and current increases as voltage decreases). To use two TT-30 receptacles with your adapter, you will need an EVSE that limits the current to no more than 24 A.

 

[webeleafowners]

I’m trying to envision a scenario where only one of the 30 amp breakers opens. How would that affect the EVSE.

We ocassionaly use a TT30 adapter on our Tesla UMC. But that is just 120 volt at 24 amp. 3 KW charge rate. Meh. Kinda like 12 amp 240 volt. Haven’t popped a breaker yet.

Be careful.

 

[Nubo]

I’m trying to envision a scenario where only one of the 30 amp breakers opens. How would that affect the EVSE.

Like any power cut, I would think. With 240V split-phase, the current flows back and forth between the two hot leads. If a breaker pops on one side the remaining hot wire will still be energized, but there will be no path for current to flow.

 

[webeleafowners]

I’m trying to envision a scenario where only one of the 30 amp breakers opens. How would that affect the EVSE.

Like any power cut, I would think. With 240V split-phase, the current flows back and forth between the two hot leads. If a breaker pops on one side the remaining hot wire will still be energized, but there will be no path for current to flow.

Yah I suppose so. An electrician I ain’t. .

 

[goldbrick]

Hopefully the current will have no place to go but often times it finds a path to ground, just not the one you want :shock:

Personally, I would never attempt this type of wiring hack as I think it's just plain dangerous.

 

[smkettner]

OK the adapter is designed for RV use and virtually all common RVs have no 240v appliances so the hots are isolated.

If you want to ensure additional safety, a pair of relays could be added same as the "quick 220" set up that many use.

 

[VinceGlorioso]

Well, the adapter arrived to my home today. I checked it with a multi-meter and it's wired exactly the way I thought it was going to be.

The two grounds are connected, the two neutrals are connected, and one "hot" goes to the "X" and one "hot" goes to the "Y" contact in the receptacle end.
I won't be able to test it any time soon, but I can answer questions about it.
Vince