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Wall Charger Install Questions

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Hi All!

Just ordered the new Model X. Due to driver some time early to mid March. I have the Tesla Wall charger coming in Monday and an electrician scheduled the following Monday for a garage install. Question is, what is the ideal amps that the circuit should use for the wall charger? Without expense in mind for the Tesla wall charger? Is there a point where it doesn’t make much of a difference in time to charge? Thanks!!
 
90 Amps is recommended. The newest cars only can use 32 A for now, so that means you need to use a 50 A breaker. Last year they could charge at 72 A, therefore needing a 90 A. If you may get another Tesla and install a second charger in the future, I would still recommend 90 A. I suspect Tesla will start making higher amperage on board chargers available again pretty soon, especially for cars like the Roadster or Pickup. Most of the cost of installation is labor unless your garage is really far away, so I vote for a 90 A circuit.

I could only install a 80 A in one house, but got 90 A in the other house. When visiting my mother, she only has 50 A available, and it is MUCH slower. Can take over 12 hours to fully charge.

FYI, circuit breakers need to be oversized for continuous loads. So, to pull 72 A you need to have a 90 A breaker. (80% max).
 
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90 Amps is recommended. The newest cars only can use 32 A for now, so that means you need to use a 50 A breaker. Last year they could charge at 72 A, therefore needing a 90 A. If you may get another Tesla and install a second charger in the future, I would still recommend 90 A. I suspect Tesla will start making higher amperage on board chargers available again pretty soon, especially for cars like the Roadster or Pickup. Most of the cost of installation is labor unless your garage is really far away, so I vote for a 90 A circuit.

I could only install a 80 A in one house, but got 90 A in the other house. When visiting my mother, she only has 50 A available, and it is MUCH slower. Can take over 12 hours to fully charge.

FYI, circuit breakers need to be oversized for continuous loads. So, to pull 72 A you need to have a 90 A breaker. (80% max).


This is recommended even if it’s the newest Tesla w/ the lower onboard capability? No issues w/ it providing too much power? Wall charger will regulate?
 
I'd put in a 100A circuit if you might add a second charger in the future. That's what we have. The HPWC's currently do a simple split, 40A to each car. If we unplug one car then we can max out at 72A or 48A. And you only have to run one set of wires for a shared circuit. We installed one with an extra box in the conduit where we added the second charger's wiring.

You might be limited by the load calc, which will tell the electrician how much current you can use for the charger given the other loads in your house. In that case, I'd install wiring for the max amps allowed (not more than 100A). Relative to the entire cost, the wire cost is not too bad, and you'll have better options for future upgrades without rewiring.
 
Check out this thread, When did X100D onboard charger change to 48A?

Seems 48A is the limit on new cars. Your electrician may find when they do load calculations that you have other limiting factors.

I went with a 50 Amp circuit because I want the option of removing of the HPWC and replacing it with a NEMA 14-50 if I decide not to replace my X with another Tesla in 2 years at the end of the lease.
 
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Check out this thread. When did X100D onboard charger change to 48A?
it appears the charging limit is 48A on new cars

I have a 50A circuit since I wanted to be able to replace the HPWC with a NEMA 14-50 if I get a non-Tesla EV at the end of my lease. Also, the permitting in my city is different about 50A.

With my setup I charge at 40A which adds 10KW/hr. I have a 75 KW battery and never use more than 60KW. So if start charging at 10PM, when the rates change, I am full by 4AM. In my situation I see no need to go with any higher amperage.
 
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To answer your question, in the purest sense, what you set the charger for when installing it has nothing to do with what car(s) you have. You set the charger for the maximum that your home can safely deliver, based upon the panel and current demands by the rest of the circuits. Then, you set your car to draw what amperage you want, limited the lower of the car's max draw and by what the charger can deliver.

As others have pointed out, putting your charger on a 100 amp circuit enables you to charge an older Tesla that can draw 80 amps or, if you one day own two Teslas (or have a friend, relative, or passer by charging also), you can take advantage of the load sharing ability to deliver up to 40 amps to each car. (This load sharing actually works with up to four wall chargers on a single circuit.)

In short, if your panel and current loads support it, there's no reason not to install your charger on a 100 amp circuit. Doing so future proofs the installation, all for the relatively low cost of some additional copper.*

*If your panel is 400' from your garage or some other atypical installation, obviously the difference in wiring could be significant.
 
Which "wall charger" did you order? The Wall Connector (that gets hardwired), or the Wall Connector with Cord & Plug (that plugs into a NEMA 14-50 outlet)? If you ordered the hardwired Wall Connector, you should install a minimum of a 240V, 60A circuit. You can go larger to future-proof your installation. I installed a 100A circuit to my Wall Connector, but I am an electrical contractor and had all of the conduit and wire on hand. Remind your electrician to review Article 625 of the NEC. Your 60A circuit needs to have a "readily accessible" "disconnecting means" that is lockable in the open position. The 60A 2-pole breaker in your electrical panel can serve as the "disconnecting means" so long as the breaker has a permanently attached locking device. If not, simply install a disconnect switch next to your Wall Connector. If you ordered the Wall Connector with Cord & Plug, have your electrician install a 240V, 50A circuit along with a NEMA 14-50 receptacle.
 
Check out this thread, When did X100D onboard charger change to 48A?

Seems 48A is the limit on new cars. Your electrician may find when they do load calculations that you have other limiting factors.

I went with a 50 Amp circuit because I want the option of removing of the HPWC and replacing it with a NEMA 14-50 if I decide not to replace my X with another Tesla in 2 years at the end of the lease.

You made a sub-optimal decision. The circuit breaker protects the wires in the wall, so your house doesn't burn down. If the wires are correct for 100 A, they are also fine for 50 A. You can put a 50 A EVSE charger on a 100 A circuit, just like you can put a night light on a 20 A circuit.

Regardless of 50 A or 100 A circuit, the car will accept only the power it can. When it's charged, it stops, just like charging your cell phone on a 20 A circuit.
 
I currently have a Nema 14-50 plug wired in my garage. I have recently added a second Tesla to my collection. Additionally I have received 2 Tesla Wall connectors from the referral program. I would like to have both Wall connectors share a circuit using the "share" feature. Can this be done using the single 60 amp circuit? Don't need the full strength charging for both cars at the same time. Would prefer to keep the wiring needs to a minimum.
 
90 Amps is recommended.
I strongly disagree with that and all of your reasoning supporting that and think it's just a lot of useless overhead. But I know--for some people overkill is still not enough. None of the Tesla models being built now can use anything higher than 48A now, and Tesla has consistently shown a trend only downward in the max charging power over the years, from 80 to 72 and now to 48A.

People get this idea so twisted. They think they need to future proof things in terms of, "But I might have a car with a 600 mile range in the future or one that can charge from a 120 amp circuit!" That's irrelevant. Having cars with bigger and bigger range doesn't mean you magically live 2X, 4X, or 8X as far away from work do you? You live where you live and drive where you drive. You only need to refill the amount of miles you drive, whether the car has a 300 mile range or a 3,000 mile range. And in fact, in the future, with cars having more spare capacity, the urgency of needing to refill them very fast is going to be less.

So maybe think of it from this perspective: how many miles would you need to refill in about 6 to 8 hours overnight? And check this table on Tesla's site to see what size circuit would do well for that?
Wall Connector

For example, a 60A circuit will refill about 30 miles per hour on a Model X with the 48A onboard charger. That's 240 miles in 8 hours. Again, that is the fastest charging they offer now, so I think 50 or 60A circuits are a pretty good sweet spot. I would only recommend higher than that if you're planning to need to share between two cars.
 
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@Rocky_H - We all have different driving patterns. For people with consistent, regular driving patterns, and mostly local short distance, I see why the charging rate may not be important to them. In my situation, much of my driving is c. 200 mile legs, without stopping at Superchargers. I arrive late, like midnight, and have to be ready for a lot of driving early the next morning. Other days, my wife makes an early 100 mile trip into the city before I leave in the afternoon.

I acknowledge my driving is not typical. But I regularly see people who spout the "average driver drives 12,000 miles per year, so you only need 38 miles per day" nonsense. Nobody, not a single person, drives exactly 38 miles a day 365 days a year. People have unexpected trips to airports, have to visit elderly parents or children in trouble, crazy traffic jams, holiday shopping, weather emergencies, and all the other stuff that makes life interesting. Having quicker recharge can be mighty useful, even if not used every day.

It is a little like the furnace in your house. Even if most of the time it produces plenty of heat, sometimes it is below zero with high winds, and you still want enough heat to keep warm. Furnaces are overspeced for extreme weather. A car charger should, at least in my opinion, be overspeced because sometimes you do need it. (Yes, you can go to a Supercharger or an emergency homeless shelter. I prefer not to.)

BTW, the Tesla Wall Charger Manual recommends a 90 A circuit. Not my imagination or unusual driving patterns.
 
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BTW, the Tesla Wall Charger Manual recommends a 90 A circuit. Not my imagination or unusual driving patterns.

This may have been the case before, but down on the Tesla site under wall chargers it says "A 60 amp circuit breaker is recommended for most Wall Connector installations. Learn more about the Wall Connector on our support page."
 
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You made a sub-optimal decision. The circuit breaker protects the wires in the wall, so your house doesn't burn down. If the wires are correct for 100 A, they are also fine for 50 A. You can put a 50 A EVSE charger on a 100 A circuit, just like you can put a night light on a 20 A circuit. ...
Sorry, that not correct two different ways. First, when you hard-wire an EVSE, the breaker needs to match the current on the unit's nameplate, so a 50a EVSE could NOT go on a 100a circuit (a Tesla wall connector could since it's 100a capable, but that's not what you said). Second, he couldn't later feed a 14-50 with a 100a circuit.
 
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You made a sub-optimal decision. The circuit breaker protects the wires in the wall, so your house doesn't burn down. If the wires are correct for 100 A, they are also fine for 50 A. You can put a 50 A EVSE charger on a 100 A circuit, just like you can put a night light on a 20 A circuit.

Regardless of 50 A or 100 A circuit, the car will accept only the power it can. When it's charged, it stops, just like charging your cell phone on a 20 A circuit.

It is still a NEMA 14-50 connector. The 50 being the max amps they need to be certified to support in continuous use. Go ahead and pump more than that through it. But, I bet the fire inspector will call you on it if it shorts out and causes a fire.
 
We all have different driving patterns.
Yes, obviously. My recommendation covers the vast majority of uses and is consistent with Tesla's own recommendations.
For people with consistent, regular driving patterns, and mostly local short distance, I see why the charging rate may not be important to them.
"not be important"? Wow. Why are you getting that? Of course it's important to everyone, but you need what you need. People shouldn't have a big U-Haul box truck as their daily driver because there is one or two times a year they need to move some furniture.
In my situation, much of my driving is c. 200 mile legs, without stopping at Superchargers. I arrive late, like midnight, and have to be ready for a lot of driving early the next morning. Other days, my wife makes an early 100 mile trip into the city before I leave in the afternoon.
OK, that's you, but sounds unusual. You really live in a place that doesn't have Superchargers around for these 200 mile driving trips? I would say that's not most people, so that would be a little odd to apply that recommendation to people's general cases.
But I regularly see people who spout the "average driver drives 12,000 miles per year, so you only need 38 miles per day" nonsense. Nobody, not a single person, drives exactly 38 miles a day 365 days a year. People have unexpected trips to airports, have to visit elderly parents or children in trouble, crazy traffic jams, holiday shopping, weather emergencies, and all the other stuff that makes life interesting.
On this, I very much agree, and it's why the other auto makers' dinky range compliance cars were a terrible idea. It's probably once or twice every month that people deviate out of that "40 miles" range, and then people are stressed. And of course that leads to people feeling the need to keep their batteries fully charged at 100% as much as possible to be prepared for that slight unexpected 60 or 70 miles, which of course leads to really bad quick degradation of those small batteries. But, the solution to these issues is a larger battery, so that you can do these long days once in a while without worrying about it.
Having quicker recharge can be mighty useful, even if not used every day.
Um, you're talking about needing to fast recharge at home from AC electricity within the same day? So that would be like a 300-400 mile driving day around town where you live without Supercharging. That is extremely unique and is getting into the "long tail" of the 0.01% use cases. If people have a long day of driving around town, they may use 150 or 200 miles, but then they're done, and they'll be able to recharge overnight. And overnight recharging at 40 or 48 amps can still easily refill that. And again, "having quicker recharge" as you are referring to can definitely be a Supercharger for those weird once or twice a year situations.
A car charger should, at least in my opinion, be overspeced because sometimes you do need it. (Yes, you can go to a Supercharger or an emergency homeless shelter. I prefer not to.)
Well, your preference is unusual. Most people wouldn't mind getting to use an ultra fast and cheap charging station a couple of times a year for those edge cases.
BTW, the Tesla Wall Charger Manual recommends a 90 A circuit. Not my imagination or unusual driving patterns.
That is utter B.S. and I dare you to quote it. I'm certain that's not recommended by Tesla from the web site on Tesla's own site I showed earlier that showed that they "recommend" 60A circuits and from the fact that none of the vehicles they are building now can draw more than what would be supplied by a 60A circuit. So you can call it your imagination or whatever, but I'm sure the manual doesn't recommend a 90A circuit as a general thing for new Tesla buyers.
 
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The manual doesn't recommend a breaker size. It tells you the sum of maximum current that attached cars (up to 4) can draw from a given size circuit (80% of the installed breaker size with the maximum breaker size being 100 A). That is, of course, given that the switches are set properly in the master and slave HPWC's. Thus if you have one car with the 3 module charger you would need a 90 amp breaker rated to deliver 72 A. If you ever thought you might get another Tesla and want to charge them both simultaneously you should probably max out at 100A which would allow two cars with 2 module chargers to draw up to 40 A each at the same time.

What someone wants to actually do vis-a-vis his use, schedule, service capacity etc can be very varied. I'll just say this: if you are going to get an electrician in and pay him to pull cable, you might as well max out. Those who have purchased 6 figure cars but want to save a few hundred $ can, of course, rationalize that their driving habits are such that a 110V wall outlet is sufficient. Up to them. But the general principal that you size electrical equipment for peak demand - not average or median or even 90th %ile demand still stands.
 
I fee so confused still. So many opinions. Overall this will be my only Tesla. It’s the brand new model x and I will take delivery in March. It sounded like things may have changed w/ the newest models. I ordered the black wall connector/charger from Tesla ($500). Overall based on the above facts what do I tell the technician to install at?