# Wall Connector - Does power output adjust dynamically based on power available at the utility meter?



## Taym (May 9, 2016)

Hi everyone. While I wait for my Model Y to be delivered (end of August), I am preparing my garage. 

I currently already have an EnelX Wall Charger, which I use for my electric Smart city car. 
I will be able to use it for my Model Y as well, but since I may have to charge both cars at the same time, I am also considering to buy a Tesla Wall Connector, of course, which is also going to be much more feature rich, cofigurable via App, and a better match to my Model Y. 

But, the EnelX Wall Charger has one feature I am not sure the Tesla Wall Connector has. 
The EnelX unit monitors the total power output at the utility meter. I have a max of 6.6kW available. The wall charger unit, then, only draws the maximum available power at that moment, and adjusts continuously, so that I can prioritize power use in my apartment. So, if, say, I am using 1.5 kW in my home, the EnelX wall charger will only allow 4.5kW flow into the car, therefore preventing the utility meter to flip due to excess power demand. 

Do you know if the Tesla Wall Connector is capable of something similar? 

Thank you in advance!


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## Feathermerchant (Sep 17, 2018)

I don't think the Tesla wall connector can do that. You can set the charge Amps from the Model Y though as an upper limit and the car will remember the setting. BTW I don't think you need a wall connector at all. Just an outlet to plug in the EVSE that comes with the Model Y.


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## Taym (May 9, 2016)

*Edited response to provide more details:*

To clarify: I am in Europe. 220V standard in every home.
I have a 6.6kW contract with my utility (Enel). With 220V, that amounts to 28/30Amps of available output, which you can use entirely.
However, standard wall outlets here will only allow a 16A output maximum, each outlet - yes, it is an outlet/plug limitation; it may also be a limitation with cabling, in some old electric systems, but, not so, usually -. That means that you can draw up to - say 28A in your home, but not all from one single wall outlet.
This 16A wall outlet limit is the number one reason why one would want a wall adapter (and why I already have an EnelX Wall Charger for my other electric car): so that you can draw more than 16 A (3.5kW), up to whatever your contract with your utility allows (6.6 kW in my case, the maximum available in most places in Italy. I hear that in other parts of EU you can go up to 11kW with a single phase - L + N - line).

So, Tesla wall adapter will decrease charge times quite a bit.

Edit: with a 6.6kW contract, you actually get to use up to 32A , that is 7.1kW, for a limited amount of time, before the utility meter circuit breaker flips.


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## Feathermerchant (Sep 17, 2018)

Hmm My car(s) came with an EVSE that can do 32A. It just requires a 40A circuit (80% of 40 is 32) to operate. Being that you are in Rome, do you need fast charging for your commute? We charge only once a week here.


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## Taym (May 9, 2016)

Just FYI, I edited my message above before seeing your reply, just to offer more details 

So, look, _in general_, I agree with you 100%, and I am perfectly OK with the EnelX wall chaerger I already have, and, in theory, I could live happily with a standard wall outlet (16A). A Model Y has such a range that that would be no major issue.

I just prefer to setup my garage so it can use available energy at its best,* just in case. *I know there will be *that *day when we forgot to plug the Model Y and now we have little time to charge it and getting 80% more power and more range in the little time available will be a day saver.
Just that.

As to my Smart, that's a whole different story. It's so primitive as compared to a Tesla, and it only comes with a 17kWh (!!) battery, which gets you a 130 Km of real range. That's the car you want to use in your daily commute in Rome (the city), but Rome is farily large after all, it is totally possible that you need to charge in the middle of the day, and a faster charge can make the difference... *with a Smart*, of course.

Hey, I see you're in Texas? I so want to visit it. I'd so get a Cybetruck if I lived there!


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## Feathermerchant (Sep 17, 2018)

Are there any Superchargers nearby?

I ran two 50A circuits so I could charge both cars. I have Gen1 Tesla EVSE's. They were cheaper to buy used and can operate up to 40A. I now have both cars turned down to 20A and we only charge on Sundays. We don't have TOD rates or anything but it's easier on the grid because Sunday is the lowest use day of the week. We don't work anymore but I rode the train from the station ~1 mile from my house anyway. So I have found that I don't need near the amount of energy I thought I would for two cars. If doing it again, I'd probably only pull one circuit and share one EVSE between the two cars. You have a lot less energy available but you may not need as much as you think.


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## Taym (May 9, 2016)

So, going back to the original topic: I understand the* Gen3 Wall Connector *(latest, currently sold) is not yet configurable via App. So, the way to limit the amount of energy used during charging is via the car itself, which *is* however configurable via App. Is that correct?

Thank you,


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## garsh (Apr 4, 2016)

Taym said:


> However, standard wall outlets here will only allow a 16A output maximum, each outlet - yes, it is an outlet/plug limitation; it may also be a limitation with cabling, in some old electric systems, but, not so, usually -. That means that you can draw up to - say 28A in your home, but not all from one single wall outlet.


Are you able to install a different type of socket in your garage that can deliver more than 16A?
The Mobile Connector that comes with the car is capable of delivering 32 amps at 220v..

Here in the states, a NEMA 5-15 is the standard home outlet, but we use NEMA 14-50 for high power items like electric ovens and EVSEs.
Or are all electric ovens required to be hard-wired there?


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## Taym (May 9, 2016)

99% of home appliances, including electric ovens, use Schuko 16A plugs/outlet. Electric ovens, dryers, washing machines, freezers, fridges, and what not. 
Nothing needs to be hard-wired. I am not aware of any home appliances needing more than 16A. Rember we use 220-240V normally, there's no 120V anywhere here. 

You can install other sockets if needed, to deliver >16A. But, I don't see why doing that instead of a Wall Connector, then. Cost, maybe, but I would not be sure. You'd need to install dedicated circuit breakers and protections which are built-in with the Wall Connector. And, you would not have all the convenience of a Wall Connector (firmware upgrade, future integration in app, etc).


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## Taym (May 9, 2016)

240V at 16A = 3.8kW . I don't know of any modern home appliance that needs more than 3.8kW peak. Most homes here operate at 3.3kW max at the utility meter, so there would not even be any real market for such a thing.


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## Feathermerchant (Sep 17, 2018)

To adjust the charge current, you have to be n the car. You can start and stop the charge using the App but you cannot set the charge rate.


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## Long Ranger (Jun 1, 2018)

Taym said:


> 240V at 16A = 3.8kW . I don't know of any modern home appliance that needs more than 3.8kW peak.


Higher power appliances are pretty common in the US. Electric clothes dryers are typically 4-6kW and an electric stovetop plus oven would often be 9.6kW. But I do recall the standard in Italy is to line-dry clothes, and cooking is probably done with gas.

As you're discovering, I think you'll be a bit disappointed with the configurability of the Wall Connector. Multiple Wall Connectors can share power between themselves intelligently, but there's no smart sharing with other circuits or devices. I suppose Tesla could add that in the future, but I wouldn't count on it.

As others have said, the charging configuration from the app is very limited. You just have a slider to set the SOC limit and the ability to start or stop charging. Hopefully that will improve, I know lots of people have asked for more. You currently have to be in the car to adjust the charging current or scheduled charging time.


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## JasonF (Oct 26, 2018)

Taym said:


> Do you know if the Tesla Wall Connector is capable of something similar?


It took me a little while to figure out that you probably meant 6.6kW _at any given moment_, not total for the day.

If I understand that correctly, you can control that by setting a limit to the amps in the car.

While I don't have one (so I don't know how to set one up) I believe you can set an amp limit on a Wall Connector as well. Hopefully someone will chime in with instructions.

What you can't do though is have the car or the Wall Connector reduce or increase its amp usage depending on how much the rest of the house is using automatically. It's a one-time setting.


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## Taym (May 9, 2016)

Long Ranger said:


> Higher power appliances are pretty common in the US. Electric clothes dryers are typically 4-6kW and an electric stovetop plus oven would often be 9.6kW. But I do recall the standard in Italy is to line-dry clothes, and cooking is probably done with gas.
> 
> As you're discovering, I think you'll be a bit disappointed with the configurability of the Wall Connector. Multiple Wall Connectors can share power between themselves intelligently, but there's no smart sharing with other circuits or devices. I suppose Tesla could add that in the future, but I wouldn't count on it.
> 
> As others have said, the charging configuration from the app is very limited. You just have a slider to set the SOC limit and the ability to start or stop charging. Hopefully that will improve, I know lots of people have asked for more. You currently have to be in the car to adjust the charging current or scheduled charging time.


Stoves are normally gas-powered across the country, yes.
When they are not (unlikely but absolutely possible, you can't have methane gas everywhere obv.), they *can *be >6kW. Most electric stoves are not, however. Meaning: if you get an electric stove from Ikea, it'll come with a 16A plug. But yes, there are some more power hungry products in that category.

Dryers are quite popular. Dryers are often built in functions of washing machines. That's what I always had, for example. You can opt for a separate dryer of course (considered a better solution, but also taking more space, so not practical when you live in an apartment); but those *also *will all use a 16A outlets, washing machines, dryers, and combos.

I really can't think of any *home* appliance today here that requires you to use a different power outlet than the standard 16A. There _used _to. Large freezers, and the like, but I haven't seen any such thing in decades. Again, I suppose the 220V (which actually were bumped up to 230V 20 yrs ago, and which often are, when measured, 240V) helps a lot, as you will need less Amps to get to the same power, of course.

Oh well. Anyway, yes, I see even the Gen 3 Wall Connector is not very feature rich. Hopefully, it'll improve over time.
Thing is, if I want to go above the 16A threshold, Tesla Wall Connector still is somewhat appealing.


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## Taym (May 9, 2016)

JasonF said:


> It took me a little while to figure out that you probably meant 6.6kW _at any given moment_, not total for the day.
> 
> If I understand that correctly, you can control that by setting a limit to the amps in the car.
> 
> ...


"Total for the day" would be *kWh* (Energy), not kW (Power). Those are two different units of measure.

Yes, I meant 6.6kW *peak *(=at any given moment).

As to Energy, I've been averaging 20-25 kW*h* (Energy)/day in the last 30 days, as I look at my graphs here. My max consumption is usually 35kW*h*/day when I am charging my car (not yet a Tesla).

Wall Connector: ok, so it looks like it won't dynamically adapt its output. Now that I think about it, to do so it would require a Amp or Power sensor of sorts to be placed at the utility meter (that's what my other wall chargder does, in fact), and the Tesla Wall Connector does not come with that. Not even Gen 3.


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## Feathermerchant (Sep 17, 2018)

On average how many miles do you drive per day now?
Around town the Model Y will use about 1 kWh for 4 miles. At 70 mph or so (113 Kph) about 3 miles per kWh. 
That may help you figure out where to set your current draw to charge your Model Y.


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## JasonF (Oct 26, 2018)

Taym said:


> Wall Connector: ok, so it looks like it won't dynamically adapt its output. Now that I think about it, to do so it would require a Amp or Power sensor of sorts to be placed at the utility meter (that's what my other wall chargder does, in fact), and the Tesla Wall Connector does not come with that. Not even Gen 3.


I believe you can make this work by thinking 4th dimensionally:

Set the car to 13A limit, which would be about 3.1kW (and the maximum continuous allowed on a 16A circuit). I looked up amp usage for European air conditioners, I don't know if you use one, but I threw that in just incase - about 2.0kW - which totals 5.1kW. Then all you have to do is time your car charging so it's at a time when you're using less than 1.5kW other than the car and the aircon. If you can, that would make nighttime charging the best, if you can't, arrange it so you can charge between dinner and bed.


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## Bigriver (Jan 26, 2018)

Taym said:


> Most homes here operate at 3.3kW max at the utility meter


My mind is blown!! I could have peaks in excess of 30 kW if I were charging my model X (72 amps @ 240 V), turned on the clothes dryer, had both central a/c units running, and anything being cooked in the kitchen. Not typical to have all these at once, but I also don't spend time thinking if I need to turn anything off to turn something else on.

Thanks for the mini education on standards in Italy. Americans are used to such excess!


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## Feathermerchant (Sep 17, 2018)

Bigriver - I'm guessing that your house is 2-3 times bigger than his. 
At the charge rate you quote, your X would be fully charged from fully dead in about 6 hours. That seems excessive too.

To the OP you can schedule charging which may be helpful. It is done from in the car too. Not the App.


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## JasonF (Oct 26, 2018)

Bigriver said:


> Thanks for the mini education on standards in Italy. Americans are used to such excess!


It's not that Europe is more efficient, it's a different scale. The homes are less than half the size. Air conditioners in Europe have more strict efficiency requirements, so smaller units and mini-splits are more common than having a 10kW condenser outside. Ranges often have fewer burners, refrigerators are smaller. American homes are designed to be islands, where you can store and cook large amounts of food, and house lots of people, while Europe is just about enough space.

Which reminds me - since 2020, I wonder if work-from-home was much more shocking to Europeans, who generally don't have the space for it.


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## Bigriver (Jan 26, 2018)

Feathermerchant said:


> At the charge rate you quote, your X would be fully charged from fully dead in about 6 hours. That seems excessive too.


Oh yeah, my X can charge fast, much faster than needed at home. I didn't define it, that's just how it was in late 2017 (72 amps) and our charging set up supports it. Tesla max is now 48 amps.



JasonF said:


> it's a different scale. The homes are less than half the size


I'm quite aware of that. Most of my friends and family were raised outside the US. I was just truly surprised to see such low peak kW. The total kWh was in line with what I expected.


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## Taym (May 9, 2016)

So, this is becoming an insight in different energy consumption patterns between Eu and US. Interesting and funny.

There are several factors at play that you should consider.

Factor n. 1 si certainly size. When I refer to 3.3kW or 6.6kW, I am thinking of a typical apartment. Mine is 130square meters, and it is considered average/large. What you should be thinking is an apartment in Manhattan, which is how may people live here, not a large house in the suburbs. As somebody corrected pointed out above, there's a scale component in understanding all this. Scale does not affect everything, but it does affect AC and Heating massively, for example. If you have an independent house outside the city, you'd certainly not have a 3.3kW contract with the utility, not even here, of course.

Factor n. 2 is voltage. EU operates at 230-240V. That means that all appliances that in the US operate at 120V, here operate at 230V. There's a lot of implications with that. Cabling can be smaller, and devices will use less power to get the same Amp. There's some efficiency opportunity right there, at appliance design level itself. 
Problem is, obv., that 240V is more dangerous, and can effectively kill you. We used to have 120V in homes in the 60s. That changed across EU.

Factor n. 3 is that electric heating is not popular. Heaters are usually gas powered. If you have electric heaters, then, again, it's a whole different story here as well.

3.3kW is the standard electricity contract you get in cities. Admittedly, though, more and more people are switching to 6.6kW, which is obv. more convenient. Personally, I've been at 6.6kW since 2006, and, I'd never go back. I'd increase max power if it was easily available, but it is not. I'd need to switch to a three-phase system, which requires some partial electric system redesign, and I postponed that. But, I will. That will bump up my contract to 15kW max. Of course, you can technically go way past that, but I would not have a need for that. 
Also, EV adoption is changing all of this. My prediction is this will change _a lot_ soon and households will start to increase their contractual peak threshold quite a lot in the coming years.

In homes, however, it is common to avoid having dishwashers and dryers and electric oven on at the same time, for example. People just tends to be more cognizant of that, and develop habits accordingly. I have 6.6kW because I hate to do that, but many are just fine with that. Most devices are programmable, of course, after all. 
It is also more and more common to use load management systems in your home main switchbox. As you may know, these are devices that prioritize some lines over others. If you're reaching a specific consumption threshold, some of your home electric lines will switch off, and others will stay on.

There has been, in the last 20 years mostly, a strong push toward efficiency. Appliances have become in general much more efficient, it is a great selling point for manufacturing not only because of course they're perceived as more "green", but because if your dryer maxes at 1.6kW instead of 3kW, you don't have to worry about the utility meter flipping. 

My home is quite "smart". I have sensors on most lines, power sockets, and appliances. And, I have been very surprised at how efficient some devices are. My AC system (Daikin) is powered by three outside chiller engines, each controlling two inside units. Each engine is rated 1.6kW maximum, but at full blast they _rarely_ reach that (actually, they *never did* so far, reaching a max of 1.4kW, only occasionally). Once they successfully reach he desired indoor temperature, keeping it there requires more or less 100W-300W per engine, depending on fan speed, how many inside units are actually on, etc. This is a fairly powerful system, that can drop my apt temperature extremely low and quite fast if I wanted to. I expected it to be way more power hungry. And, energy efficiency was one of its selling points - rightfully so, I have to say. 
My coffee-maker peaks at 1.5kW every time while making coffee. Imagine that! 1.5kW!  That's a very simple machine with a resistance inside. It is quite telling of how massively inefficient the simplest device can be.

Also, there's been quite big a push to install good windows (incentives, tax cuts, etc.). As I renewed my apartment windows, I literally cut to one half my yearly heating consumptions costs (these are actual measures, not estimates) in the coldest years.

In sort, I think technology in appliances, voltage, and habits all contribute to a possibly lower average energy use. 
Of course, keeping scale in mind.


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## JasonF (Oct 26, 2018)

If you want to put into context the kW limits in Italy vs the US: I just used an online calculator to figure the average 200 amp suburban home service in the US: That comes to 44kW at 220 volts. The big difference is that it's a hard limit vs a contractual limit. A contractual limit would be more like some areas in the US where you're billed at a higher rate if you go over a certain kWh per month - divide that by 30 days, and you have your daily "limit". Except here they generally don't cut you off, and the billing rate increase isn't _that_ much higher, just a few cents per kWh.


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## Feathermerchant (Sep 17, 2018)

130 Square meters is 1,400 sq ft. A small house or average apartment.
Our house is a modest 2,100 sq ft (195 sqm) with 4 bedrooms, 2 baths and a 2 car garage. The 400 sqft garage is not included in the 2.100 sq ft. We raised out 3 kids here. Two bedrooms are now used for sewing/crafting. There is one A/C unit that is 36,000 BTU and draws something less than 3kW. Even though there is only one unit it is two speed and draws <2kW in low speed where it runs at temperatures below 100 degF (38 degC). We have a 200A capable service (48 kW) which is pretty standard in the US. We and some neighbors are connected to a 25 KVA transformer. There is no contract for a specific amount of load. We are in an area where we can choose our energy provider and rate. We pay 9¢/kWh for now. The contract for electricity varies but ours is a two year deal. Some are month to month and some are 3 years. The wired infrastructure is operated by a regulated monopoly and the generation is deregulated. This arrangement varies around the country and within some states.
I worked for the regulated utility and they are interested in EV effects on the grid. So they are monitoring several customers. The outcome may affect how they design the grid especially sizing transformers.
Our larger appliances like A/C, heat, water heater, range, and clothes dryer are 240V but everything else is 120V. In out house the heat and water heating are gas with gas outlets at the range and clothes dryer.
There is the start of a push to eliminate gas from houses in large cities for pollution reasons.


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## Taym (May 9, 2016)

JasonF said:


> If you want to put into context the kW limits in Italy vs the US: I just used an online calculator to figure the average 200 amp suburban home service in the US: That comes to 44kW at 220 volts. The big difference is that it's a hard limit vs a contractual limit. A contractual limit would be more like some areas in the US where you're billed at a higher rate if you go over a certain kWh per month - divide that by 30 days, and you have your daily "limit". Except here they generally don't cut you off, and the billing rate increase isn't _that_ much higher, just a few cents per kWh.


Here you have a % increase over the contractual threshold that is allowed for a specific amount of time, at any given time. If I recall correctly you can draw 20% more (if you have 6.6kW you can go up to 8kW), for one or two hours (if I recall correctly), then they cut you off.

However, there are other contracts (typically for businesses) where they will simply charge you more. 
In my office, contractual power is 150kW, with no limit if you pass that threshold; just an extra per-minute fee.


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## JasonF (Oct 26, 2018)

Taym said:


> Here you have a % increase over the contractual threshold that is allowed for a specific amount of time, at any given time. If I recall correctly you can draw 20% more (if you have 6.6kW you can go up to 8kW), for one or two hours (if I recall correctly), then they cut you off.


Ah, that's why - most of the US has laws that prevent people from being cut off from electricity unless there's an actual emergency.


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## Feathermerchant (Sep 17, 2018)

Or they don't pay their bill. There are database tags for those on critical medical devices.


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