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RV / EV in one?
- Thread starter bobmane
- Start date
Most campgrounds use NEMA 14-50 for RVs, and TT-30 for trailers.
Instead of hard wired Tesla Wall Charger, some people just install a NEMA-14-50 and use a Tesla mobile charge connector for their car... So then you could switch uses easily. But then you are limited to 40A (or in some cases 32A) max charging rate for the Tesla.
Instead of hard wired Tesla Wall Charger, some people just install a NEMA-14-50 and use a Tesla mobile charge connector for their car... So then you could switch uses easily. But then you are limited to 40A (or in some cases 32A) max charging rate for the Tesla.
NEMA 14-50 is the universal standard for big power, used by most RVs (what RV parks call "50 amp service") - and the only big power adapter included in the standard UMC kit is a 14-50. (Others are available, of course.)
Lasttoy
Active Member
No. A 50 amp rv recpticle is 2 110v circuits technically. Class A RV have the systems split in half. Front ac is on one circuit, rear ac is on other half. There are 2 different 110v breakers inside. A friend of mine plugged their RV in a regular 14.50 and burnt up the entire electrical on RV. Be very careful how you wire them. I have a 50 amp classA and 30 amp class C plugs on one side of house. A 50 amp 14.50 on other side for Tesla.
Download the diagrams before you wire them.
Download the diagrams before you wire them.
TT-30 is an unusual older standard. 30A at 120V, the odd three pronged angled plug in the second post. The TT stood for travel trailer I believe - it was mostly used for camping trailers AFAIK. You can charge a Tesla with one at up to about 20A, but it's still pretty slow.
Either the RV wasn't complying with the standard or the outlet he plugged into wasn't. 14-50 is 14-50, and all RVs and EVs should be able to use the same outlets.
The "2 110V circuits" you're talking about are by taking the Line 1 and Line 2 sides of the 14-50 and running things between each of them and ground. An EV gets the full power by running from L1 to L2.
You do have to be careful about adapters going to 14-50, though - there are TT-30 to 14-50 adapters for RVs that won't work for an EV, because they connect both the L1 and the L2 legs of the 14-50 side to the single Line input of the TT-30. That's fine for those RVs that don't have 240V devices, but means the EV will get no power from it.
Can't to 240V with a single breaker, because you have two hot lines involved. Need a new box...
You should be able to change out to a quad breaker. 50 amp 240 and 2 20 amp (
Basically, it would require you to change out all your existing breakers except the 100
Attachments
NEMA5-15 household outlet = 120V @ 15A... One ~20A breaker...
TT-30 "Travel Trailer" campground outlet = 120V @ 30A... One ~30A breaker...
NEMA14-50 RV campground outlet = 240V @ 50A... TWO ~50A breakers...
The breaker sizing and wiring size behind the outlet can vary a bit from place to place...
Best to be conservative with your continuous (EV charging) power draw to avoid overheating the outlet or breaker.
For NEMA5-15 maybe only pull 12A max safelty ( 120V@12A=1.44kW )
For TT-30 maybe only pull 20A max safely ( 120V@20A=2.4kW )
For NEMA14-50 maybe only pull 40A max safely. ( 240V@40A=9.6kW )
Some NEMA14-50 are wired with only wiring rated for 40A and/or installed with 40A breakers. In that case, don't plan to EV charge at more than 32A ( 7.68kW )
Tesla will charge using 240V from NEMA14-50 so needs it wired with "two hots" to get proper 240V.
Some campgrounds wire the same 120V circuit to both sides of a NEMA14-50 socket, and most RVs are only 2 sets of 120V appliances, so do OK with that.
But in those cases, you may find that Tesla charging and campgrounds doesn't provide full power capability.
"Normal" NEMA14-50 wiring:
In the above, the 2 120V circuits are each half of "split phase" power, and so sum to 240V across.
If a campground runs the same non-split phase 120V to one or both sides of a 14-50 socket then you get 0 volts when trying to get current from X+Y
I think some people have concluded that their UMC was bad, a breaker must be blown or some such when it was really just a case of incompatible wiring. Campgrounds may "bend the rules" of the typical way to use that kind of socket.
TT-30 "Travel Trailer" campground outlet = 120V @ 30A... One ~30A breaker...
NEMA14-50 RV campground outlet = 240V @ 50A... TWO ~50A breakers...
The breaker sizing and wiring size behind the outlet can vary a bit from place to place...
Best to be conservative with your continuous (EV charging) power draw to avoid overheating the outlet or breaker.
For NEMA5-15 maybe only pull 12A max safelty ( 120V@12A=1.44kW )
For TT-30 maybe only pull 20A max safely ( 120V@20A=2.4kW )
For NEMA14-50 maybe only pull 40A max safely. ( 240V@40A=9.6kW )
Some NEMA14-50 are wired with only wiring rated for 40A and/or installed with 40A breakers. In that case, don't plan to EV charge at more than 32A ( 7.68kW )
Tesla will charge using 240V from NEMA14-50 so needs it wired with "two hots" to get proper 240V.
Some campgrounds wire the same 120V circuit to both sides of a NEMA14-50 socket, and most RVs are only 2 sets of 120V appliances, so do OK with that.
But in those cases, you may find that Tesla charging and campgrounds doesn't provide full power capability.
"Normal" NEMA14-50 wiring:
In the above, the 2 120V circuits are each half of "split phase" power, and so sum to 240V across.
If a campground runs the same non-split phase 120V to one or both sides of a 14-50 socket then you get 0 volts when trying to get current from X+Y
I think some people have concluded that their UMC was bad, a breaker must be blown or some such when it was really just a case of incompatible wiring. Campgrounds may "bend the rules" of the typical way to use that kind of socket.
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I don't want to recommend anything. You should consult a professional electrician if you have any doubts.
I am saying that I have heard of some places that installed lower gauge wiring and/or smaller than usual circuit breakers, so you shouldn't just assume that every NEMA14-50 is good for 50 amps everywhere you go.
I think it is better if you draw the minimum current you need to get the state of charge you need in time. ( Like overnight charging can be slower. )
Trying to pull 50amps, or even 40 at campgrounds with worn old NEMA14-50s can be problematic. Better to do 32 to be safe.
There are different options on how you can do things at your own house.
I am saying that I have heard of some places that installed lower gauge wiring and/or smaller than usual circuit breakers, so you shouldn't just assume that every NEMA14-50 is good for 50 amps everywhere you go.
I think it is better if you draw the minimum current you need to get the state of charge you need in time. ( Like overnight charging can be slower. )
Trying to pull 50amps, or even 40 at campgrounds with worn old NEMA14-50s can be problematic. Better to do 32 to be safe.
There are different options on how you can do things at your own house.
TT30 is not an old standard. It is used by the vast majority of New RV’s of any type including trailers, fifth wheels and Motorhomes with one AC. Most dual or triple AC rv’s use 50 amp 240 service.
dgpcolorado
high altitude member
I set my car at 24 amps when using TT-30 and it worked fine. If the outlet can't handle that current it isn't wired correctly — always a possibility, I suppose. Still rather slow charging at 2.9 kW, however.
I do use a lower current — 30 amps — when using 14-50 outlets but that's to lower the heat and wear on my UMC and speed usually isn't a concern when charging overnight at 240 V. That's what I use at home, as well as at campgrounds with "50 amp" service.
Charging on TT-30 at Zion National Park:
Agreed. There was a time when the cars limited 120V charging to less than the 24A a TT-30 should be capable of, but that's apparently no longer the case.
