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Home Charging

Home Charging

Hi people,

I have a reservation for a Model 3, as many of you may have, but am curious about home charging. I live in an older house (1960~) with family and one thing that worries me is not being able to home charge (albeit, fast) due to the age and wiring. Are there any issues that would come with having an older house? For the Tesla-installed home chargers, is it accurate that it pulls around 40-50 amps? I am no electrician and have no clue on how most of it works, but basically even using a microwave with a vacuum trips a breaker and I've had to put stuff like my PC behind UPS, and I am assuming trying to charge a Tesla would do the same. Someone please correct me if I am totally wrong, which I hope..

Do the home chargers have any option for an extended cable? Basically I wouldn't have the vehicle in a garage all the time, very rarely, so it would be a hassle to have to park it in the garage to charge it due to our garage layout, the fact that it's on the opposite side of the house as the main breaker, and there's not much space. It would be easier to have an extended cable to use. I have seen many people with home chargers in videos but never much more than what is stock. Right now I'm more set on just using superchargers since they're pretty close and would probably be faster and more convenient since I don't drive much locally.

Earl and Nagin ... | 29 décembre 2017

If it is anything like the Roadster, S, or X, you should be able to slow the charge rate down to 16, or 24 amps. You may be able to manage. You may want to upgrade the electrical service into your house though, especially since you may want to get another EV in the future or charge faster, in addition to avoiding the other gremlins you seem to be living with. This will probably cost $1,000 or more -- consult a good, local electrician.

TheMikeA | 29 décembre 2017

I don't think we'll be living here for more than another year or two, so probably not worth paying for electrical upgrades at this point just for an EV. I wasn't aware you could set charge rates though, if that's possible in the S/X I'm sure it is in the 3 too. Thanks for mentioning.

stevenmaifert | 29 décembre 2017

Do you have a 240V electric dryer outlet anywhere near where you could park the car to charge? There are adapters for the 2nd Gen UMC that would work with that.

stevea137 | 29 décembre 2017

At a minimum, you would have to run a new circuit from your breaker box to where you want your charge point. You really don't want your charging circuit shared with anything else, mainly because you can't get any useful charge rates off 110V anyway, and the only 220V circuits that may be in your house would be electric stove, electric clothes dryer, and electric hot water heater.

If you are going to install a new circuit, you might as well spend a few extra dollars and install wiring capable of handing 40A if your service and breaker box as the capacity for it. If not, install the highest amperage 220V circuit you can (110V charging is both slow and horribly inefficient).

And if the costs of those scare you, wait till you see how much an extension cord rated for 220V 40A at 50ft costs, lol!

TheMikeA | 29 décembre 2017

> If you are going to install a new circuit, you might as well spend a few extra dollars and install wiring capable of handing 40A if your service and breaker box as the capacity for it.

It may be all I can do, the costs aren't an issue really, and I guess it would be good to have in the home if it's sold in the future anyways.

stevenmaifert | 29 décembre 2017

Look at the rating stamped on the main breaker in your power panel. Many of the older homes as you describe have only 100A service. If that's your case, chances are you will have to live with the existing wiring.

noleaf4me | 30 décembre 2017

they make an outlet combiner that can get you to 220V using 2-110V separate circuits on different phases. It would be a pain as you'd likely need to run heavy gauge extension cords from 2 different outlets -- but you could get your charge rates up to 10-12 miles/hour. There was a forum topic on this in the past

https://forums.tesla.
com/forum/forums/combining-two-120v-240v-connector

plopeziii | 30 décembre 2017

Based on the brown outs you are already experiencing, it sounds like you need to increase the electrical service amperage to your house, before you consider doing anything. Follow @stevemaifert 's advice and check the existing service amperage to your house. It is not unusual for houses of 1960's vintage to have inadequate service amperage as electrical needs have expanded over time. You need to employ a licensed electrician and insist that they comply with current electrical codes before making any changes. Placing too much demand (increased load) on old wiring and underpowered service is a recipe for an electrical fire.

jefjes | 30 décembre 2017

I've read in another thread here that the UMC when plugged into a 110V outlet only supplies current at about 12A. If that's the case and you are going to primarily charge at local superchargers, you will probably be fine plugged into a regular 110V outlet that you have access to from where you plan on parking. Since you plan on moving soon, I wouldn't spend much upgrading your current property unless you're sure to show a return on your investment. Just keeping it plugged into a 110V outlet should help offset vampire voltage losses while it is parked at home even if it doesn't give you much of a charge. That shouldn't be a problem since the charging will mainly be at other locations according to what you said. If you use an extension cord, just make sure it is rated to handle the amp draw without over heating and causing a fire danger and use the shortest one needed which should also offset the cost of buying a larger gauge cord (probably a 12GA wire cord will be minimum).

jlxjl | 30 décembre 2017

As noleaf4me pointed out, google quick 220 converter. The converter outputs 220V at 20A for less than $300.

jdwil | 30 décembre 2017

20amp CCTs can only charge at 16amps and that's if the 2 120volt circuits are on 20amp breakers and they are on different phases. But if even one is on a is on a 15amp breaker you can only charge at 12amps and just because the plugs are on different breakers does not mean they are on different phases.

Bryan.whitton | 30 décembre 2017

If you are experiencing interruptions in service due to loads being added you might want to get an electrician out to look for lose connections to the bus bars. You may also have a lose neutral or ground connection. These are serious faults and adding circuits takes a backseat to a safe house.

We had a similar issue in our home and shortly after moving in we melted a lug mounting the meter to the bus. Fortunately it was replaceable and my electrician happened to have one so the fix was quick and painless.

Since, we have upgraded our home to a new Square D 200 AMP panel and I have installed a Leviton EVSE. It was a freebe from Honda with the Honda FIT EV lease.

You might also want to check if you have a Zinsco service panel. If so I would seriously consider replacing it ASAP. They have a history of arcing from the breakers to the bus even when seated completely. This can cause fires. When I see a Zinsco panel on a house where I am installing PV I automatically include the cost of a panel upgrade. They are really bad and have been out of business for a long time.

As for installing a standard 6.6 kW EVSE or 14-50R on a 100 AMP panel that shouldn't be a problem. If you have room to add a double pole breaker it is easy. If your panel is full with single breakers you can usually double up some singles and find room for a double pole or quad breaker for your EVSE or receptacle. I would recommend that you charge after peak hours so you aren't running your electric dryers or ranges at the same time. But you should be charging after 11:00 PM anyway. When doing a load analysis remember that an EVSE is rated as continuous duty and the load needs to be multiplied by 1.25. So a 32 amp load * 1.25 = a 40 amp load. Limit your car to 32 amps and you should be fine. With an 6.6 kW EVSE you don't need to worry about limits being set. The EVSE will do it.

Rocky_H | 2 janvier 2018

@TheMikeA, Quote: “For the Tesla-installed home chargers, is it accurate that it pulls around 40-50 amps?”

No, it’s not a fixed level that it has to be. You can install charging on a 15 or 20A circuit if you want. That might be especially applicable to your house since it’s older and might have smaller electrical capacity. Regarding the other answer you got about manually turning down the amps in the car, that doesn’t help you because you would still need to be using a circuit, and it’s really a question of how big a circuit you are allowed (by code) to fit within your house’s system.

Quote: “Do the home chargers have any option for an extended cable?”

I would recommend to probably go with a wall connector then that has the 25 foot cable.

Quote: “Right now I'm more set on just using superchargers since they're pretty close and would probably be faster and more convenient since I don't drive much locally.”

Actually that would be less convenient. Nothing beats having the car charge overnight while you’re sleeping and it always being ready to go in the mornings.

mwojcie | 2 janvier 2018

So there is good news for you with your situation with a questionable electrical situation at home. You really should probably upgrade for safety - but, your tesla is smart enough to know what you have plugged it into and will adjust accordingly so it usually does not blow any circuits. Further, you can decrease the amps that the charger pulls down to a minimum of 5 amps with is very low.

Further good news is that the M3 seems to charge faster on a lower volt/amp combination than the MS and you can charge on just a 15 amp 115 volt standard outlet. Here are my charging experiences:

Model S: In a 100 amp 220 volt dedicated HPWC the MS maxes out at 72 amps with dual chargers and a rate of
50 Miles/hr
In a 15 amp 115 volt standard house circuit the MS maxes out at 12 amps and a rate of 2 miles/hr

Model 3: In a 100 amp 220 volt dedicated HPWC the M3 maxes out at 48 amps and a rate of 42 miles/hr
In a 15 amp 115 volt standard house circuit the M3 maxes out at 12 amps and a rate of 4 miles/hr

So the M3 exceeds the MS in a 115 volt situation and the M3 only drawing 48 amps vs 72 amps in a 220 volt HPWC gets almost as much (42 vs 50 m/hr) as my MS.

So with say a 12 hr plug in you can get 48 miles of range over night. I a full day you can get about 100 miles in range, so you may not need to upgrade (other than safety for the rest of the house). Hope that helps.

globalMan | 3 janvier 2018

Anyone know if the Tesla HPWC can be installed not hard-wired but pluggable? It would be nice if it is pluggable, meaning that one can simply plug the unit into a wall socket of relevant voltage.

If not, anyone who is knowledgeable as to how to convert it, by using some kind of plug?

tesla | 3 janvier 2018

@gllivyl it doesn't come with the parts to do it, but search youtube, a number of people have done it

johnmann | 3 janvier 2018

gllivyl - I have seen several web pages and YouTube videos of people doing just that. Here’s one that came up after a quick search.

https://youtu.
be/X3tH_gnKoZg

Yodrak. | 3 janvier 2018

Mike, step 1 is to check with your electric utility to find out if it will check your service to tell you what ampacity its existing wiring can provide to your house. Hopefully it's more than the 100 amps your panel provides, but if not find out if the utility will upgrade your service to the meter at what cost. Some utilities will upgrade at no cost to the customer with the expectation of increased usage. (Note that this is not entirely the utility's decision, the state regulatory body dictates what the utility is allowed to do.)

If you have more than 100 amps available to the meter, have a certified electrician check the wiring on your side of the meter to determine what amperage can be delivered to your panel from the meter, i.e do you need to upgrade both the wire and the panel.

You write that you may not stay in your present home more than another two years. In that case it may not be worth it to you to upgrade your electric service. Find out what Level 2 or Tesla Supercharger locations are available in your area that you could use to keep your Model 3 charged to a level that you are comfortable with.

Yodrak. | 3 janvier 2018

Mike, step 1 is to check with your electric utility to find out if it will check your service to tell you what ampacity its existing wiring can provide to your house. Hopefully it's more than the 100 amps your panel provides, but if not find out if the utility will upgrade your service to the meter at what cost. Some utilities will upgrade at no cost to the customer with the expectation of increased usage. (Note that this is not entirely the utility's decision, the state regulatory body dictates what the utility is allowed to do.)

If you have more than 100 amps available to the meter, have a certified electrician check the wiring on your side of the meter to determine what amperage can be delivered to your panel from the meter, i.e do you need to upgrade both the wire and the panel.

You write that you may not stay in your present home more than another two years. In that case it may not be worth it to you to upgrade your electric service. Find out what Level 2 or Tesla Supercharger locations are available in your area that you could use to keep your Model 3 charged to a level that you are comfortable with.