So we own a lot at an rv resort in Florida. We have a fifth wheel and it is plugged into a 14-50 outlet in the back of the lot. Some sites like ours have an outlet on both sides for people backing in or pulling forward into a lot. I used the front outlet (which appears to have its own breaker) to charge the Tesla. Just for safety sake, I did limit the usage to 15 amps. At one point, both acs were running and both 14-50 boxes tripped a fuse when my wife used a hair dryer. This tells me that both services are connected and RVers should realize this even though there may be a separate box/outlet.
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Lesson learned at an RV campsite this past weekend for charging on 50 amp breaker
- Thread starter Chomlee
- Start date
fiehlsport
Tire Guy
I know in residential, a 14-50 needs to be on its own breaker. But campsites, maybe they adhere (or don't!) to their own codebook for that kind of stuff. That's a shame.
Good to know. Hopefully you talked to the management before you charged? Always a good idea because if a few folks cause problems at a campground charging their EV (not saying you were) it could cause them to implement a no EV charging policy.
I always tell everyone to ask first before charging your EV.
I always tell everyone to ask first before charging your EV.
We own the lot. I get billed directly from the provider. Also have seen some other owners who had teslas plug in. (Not 100% sure if it was the 14-50 outlet). Having said that, it wouldn’t hurt to check. Worst case, I plug into the 110 and charge the same rate as everyone’s golf cart (At +4 miles/ hour charge… ugh).
Nice! Yeah 120v charging is painfully slow. If it were me I would fill up with the 14-50 and then use the 120v to maintain. Can’t power your RV while your charging though which could be a deal breaker.
We have a smaller travel trailer Apex 245BHS ultra lite (more than what Tesla can tow
)that takes the 120v 30 amp connection. Nice thing about that is we could in theory charge an EV with the 14-50 while still having power from the 30 for the trailer to run A/C etc.This will be something we tackle when the Rivian R1S arrives (unfortunately probably more than a year from now).
We started with an ATI 24’ bunkhouse but the grandkids hated the bunks (ours also wasn’t as nice as the apexes). When we bought the lot, we put a 42’ Landmark and it isn’t moving (need a 3500 dually to comfortably tow that).Nice! Yeah 120v charging is painfully slow. If it were me I would fill up with the 14-50 and then use the 120v to maintain. Can’t power your RV while your charging though which could be a deal breaker.
We have a smaller travel trailer Apex 245BHS ultra lite (more than what Tesla can tow
This will be something we tackle when the Rivian R1S arrives (unfortunately probably more than a year from now).
your other comment does bring up another option. I could get a connector for the 30 amp line and charge from there at 120v. That would be the same as the 15 amp charging on the 220/240 line.
Towing with your Rivian (or any electric for that matter), I would suspect you would get as low as 1/3 to 1/2 the range unless towing an airstream or pop up. Then again, there isn’t a lot of data on that yet.
Yes that is also an option. The adapters can be harder to find though. I haven’t searched a whole lot but when I looked recently the TT30 adapters were out of stock everywhere I looked.
Yes the range will be much lower. 1/3 is about what we are figuring on as a worst case. I hopeful it would only be a 50% loss though.
Right now we are pulling it with a 21 Honda Pilot and it’s up near the max for that. I get between 11-13 mpg towing it with that. It has the 10 speed auto and a trans cooler.
I would strongly discourage the concept that high amp 120V charging is a preferred alternative to 240V at whatever suitable rate.
USA 120V (aka 110V or 115V) residential power distribution is based on splitting the 240 volt incoming service, with a mid "neutral" tied to a central Earth ground.
It is always a desirable goal, though never precisely achieved, that the 120V L1/Neutral side of the 240 volt line is supplying the same load power as the 120V L2/Neutral side.
If you mismatch these two sides significantly, then the mismatch current will flow in the Neutral feed and it won't be very neutral anymore(ie not very close to 0 amps flowing and not at 0 volt ground potential).
For balance, safety and efficiency, it's far preferable to charge the EV on balanced 240 volt power through a double-pole breaker (dedicated if at all possible, and strictly speaking, required so by code for any new installation). Every amp you allocate to the max charging rate in your app will be twice as much power as if you tried to do the same on 120V. Conversely, for a given overall charging rate, on 120V, the amps will have to be twice as high, the wires twice as heavy and the contribution to imbalance literally infinitely higher (significant compared to none).
I see no advantage to schemes meant to deliver high-amp 120V to the EV, except perhaps in a very unusual, and already poorly-wired installation where nearly all of the other-user 120V appliances are attached to one side, creating a bad imbalance to begin with. But in that case, the right thing to do would be to rearrange the breakers to rebalance the load, and then still proceed with 240V balanced service for the EV.
120V charging with the mobile connector is a last resort, as we all know better than nothing but not a whole lot better.
USA 120V (aka 110V or 115V) residential power distribution is based on splitting the 240 volt incoming service, with a mid "neutral" tied to a central Earth ground.
It is always a desirable goal, though never precisely achieved, that the 120V L1/Neutral side of the 240 volt line is supplying the same load power as the 120V L2/Neutral side.
If you mismatch these two sides significantly, then the mismatch current will flow in the Neutral feed and it won't be very neutral anymore(ie not very close to 0 amps flowing and not at 0 volt ground potential).
For balance, safety and efficiency, it's far preferable to charge the EV on balanced 240 volt power through a double-pole breaker (dedicated if at all possible, and strictly speaking, required so by code for any new installation). Every amp you allocate to the max charging rate in your app will be twice as much power as if you tried to do the same on 120V. Conversely, for a given overall charging rate, on 120V, the amps will have to be twice as high, the wires twice as heavy and the contribution to imbalance literally infinitely higher (significant compared to none).
I see no advantage to schemes meant to deliver high-amp 120V to the EV, except perhaps in a very unusual, and already poorly-wired installation where nearly all of the other-user 120V appliances are attached to one side, creating a bad imbalance to begin with. But in that case, the right thing to do would be to rearrange the breakers to rebalance the load, and then still proceed with 240V balanced service for the EV.
120V charging with the mobile connector is a last resort, as we all know better than nothing but not a whole lot better.
davewill
Active Member
That's assuming that the TT-30 isn't also on a common circuit with the 14-50, and you wouldn't blow a breaker anyway.
@JHCCAZ While that is a good technical explanation, I think you fell into the wrong thread:
You seem to have missed what this thread about. People are not installing high amp 120V circuits to use by choice, which you are wagging your shaming finger at. This is people using what's already available. These TT-30 outlets already exist at the RV parks, and if people need charging, and it's all they can make use of, they will. It's not "preferred", but it's better than nothing.
No one is saying it is "preferred". No one is saying it is an "advantage".
The RV parks would call the police on you if you tried rewiring their infrastructure.
You seem to have missed what this thread about. People are not installing high amp 120V circuits to use by choice, which you are wagging your shaming finger at. This is people using what's already available. These TT-30 outlets already exist at the RV parks, and if people need charging, and it's all they can make use of, they will. It's not "preferred", but it's better than nothing.
I see your point. also charging at 30 amps on a 30 amp breaker is probably “riding the max”. so being an electrical engineer, how would the loading be on the 50 amp 220/240 line with 2 15 amp acs, 15 amp (240v) charging For Tesla, and let’s just say 15 amps total on the misc 110 internal lines? I’m kind of picturing the load could be better explained as a total of 100 amps at 110/120. Would that make it (15 amp for each ac + 30 Tesla charging + 15 misc = 75 amp)? This is less than 100 so normally should be ok right? In my case throw in a hair dryer and start up of one of the acs, I guess that could throw you over the 100.
I could be totally off on my assumptions, so please correct me if I am wrong. I’m an engineer as well and just trying to find “root cause”. If the answer is “avoid using hair dryer while charging, especially during summer when ac is running” that would be easy enough to avoid.
davewill
Active Member
Sort of. A 240v circuit has a breaker on each 120v leg. So if either leg goes over 50a, the breaker is going to trip. A house (or RV) is wired so that the 120v loads are roughly split evenly between the two legs. For example, a 1200 watt hair dryer adds an extra 10a to one of the legs. So let's say one leg has 35a on it and the other has 41a on it. Plug your hair dryer into the first leg (35a + 10a = 45a) and you're OK, plug into the second leg (41a + 10a = 51a), and the breaker trips.
Probably the best thing is to unplug the car any time you're going to use something with a high draw, like a microwave or the hair dryer. Also be aware that the car might forget the lowered setting when you least expect it, so double check when you plug in. You could also try setting the car still lower. In Europe, a lot of home charging is done at 230v 10a, and 10a would not be an unreasonable level for you to try.
You could install a monitor that would show you how much you're drawing on each leg. That way you'd know where you stand when different things are running.
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Gotcha, thanks. I do have a monitor attached to the main rv plug. Now that makes sense when I watch it and see L1 and L2 blink up before giving me a value. So next time, I should wait till both acs are running and use the microwave or have the wife use the hair dryer and take note of each line. That way, I will have an idea of how much room I have on each line For Tesla charging.
btw, none of the switches were “tripped” at least visibly. I simply turned both front and back breakers off and on again and about 5 min later, the power to the rv came back on.
Well I'm sorry if anyone felt shamed, I didn't think that's what I was doing at all, and frankly I think that response is a little harsh but I'll deal with it.
The OP clearly said, a couple of times, that he is the owner of the RV Park! And he talked about charging on 30 amp 110V. So my comment had nothing to do with telling him to rewire someone else's RV park, and no one's getting arrested here unless they burn it down, which if anything I'm trying to help prevent
.So, understand that the spirit of what I was explaining was to a person who indeed has the right, and I thought the interest, in doing something about his own existing setup at his own RV park, in order to charge EVs. I certainly apologize to him, if he thought I was wagging my finger at him - not my intent at all.
On the other hand, for a non-owner user of the park who's trying to make use of the available infrastructure and not trip breakers, I would say this:
Scenario 1: You try to pull almost 30 amps, well let's call it 80% of 30A = 24A if you're minding the continuous- load rule, from an available 120V outlet, to get the highest possible 120V charge rate. This is around 2900W. If everything is in decent shape it shouldn't trip that breaker, which hopefully is dedicated (but if they're sharing circuits for 50 amp outlets, why wouldn't they be for 30 amp outlets? IDK). However, note that 24 amps is being added to the load of one pole of the upstream main breaker/fuse servicing that particular building or parking site (? no I'm not personally experienced with RV-park wiring). So if there isn't plenty of margin, it's a more significant extra risk of tripping a panel Main which would upset more people.
Scenario 2: You use the 240V 14-50, but knowing that it might be shared with another one based on historic practices, and not wanting to trip anything, you turn down the charge rate to 12 amps. This is the same ~2900W as in scenario 1, but the difference is you're only adding 12A of balanced loading, per pole, to the upstream Mains.
If you're feeling lucky, you could then go higher, up to 15A or 20A to get an even better charge rate, and yes at some point you might trip a shared 50A breaker being used by your family's RV or your immediate neighbor's RV, but you're still pulling less from upstream breaker poles.
I do understand that Scenario 1 is the original attempt to get the EV charged without tripping the 14-50 receptacle's breaker. But if there is a mix of 120V and 240V outlets available, I would think that you should prefer to run hair dryers or toaster ovens from the available 120V receptacle, and do your modest EV charging from the 14-50. I'm sure that might involve deploying a heavy duty extension cord and it's less convenient based on the way the RV is normally hooked up, but hey you're trying to adapt your situation to the EV. It's still better, either way, if you and your family can organize things to start the EV charging after everyone goes to bed. But in general I think the 240V for EV is a better strategy.
davewill
Active Member
Okay I see, but still it's not like I told him to drive up and start rewiring things, which is what I got accused of.
As a lot owner or even a leasing tenant, one would be In a reasonable position to learn the infrastructure, and then collaborate or negotiate with the manager or Association or owner regarding proposed modifications.
I recently helped, in a small way, a townhouse/condo owner who wanted to install a wall connector on the parking structure which is owned by the HOA. The electrical service needed to be run underground from her panel to the parking structure and then the physical mounting of the HPWC. There was a fair amount of resistance at first, including exaggerated fears of Teslas catching fire, the setup being a potential eyesore and so on. In the end it all worked out, and now the neighbors including HOA folks are becoming quite interested in doing the same for themselves, as everyone is starting to think about alternatives to their gas cars.
So I can see a related scenario playing out for the OP at his RV lot. There might be some hurdles, especially if inconsiderate EV owners have been driving around the country tripping breakers at RV parks, but this issue is only going to grow for legitimate users within the RV community.
I wish! It’s not your typical RV park and is definitely more like a resort. all lots are individually owned.
on another note I am 99.9% sure it didn’t overload the other lots as the resort is located in central Florida and this last particular weekend was the deadest it’s ever been with only 10% of the lots being occupied. Normally in the winter, we have had weekends where they are 100% booked and have never gotten a report of the power going out on all the lots as a result of someone overloading the circuits so I think they are pretty well set individually.
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