Welcome to Tesla Motors Club
Discuss Tesla's Model S, Model 3, Model X, Model Y, Cybertruck, Roadster and More.
Register

Charging at home

drj400m

Member
Feb 3, 2018
48
12
MN
New member so trying to jump in. I am currently looking at buying a MS and I have a question about charging set up at my home.
My current home circuit breaker has a door sticker stating max is 125 amps and I have the main breaker (2 breakers together with plastic showing 100 on each) that from what I can gather is 200 amps. So I’m unsure if breaker is 125 or 200.
Question is: can a 125 amp circuit breaker handle a NEMA 15-40 addition? I would have an electrician do the work (I am sure by the question you can tell not electrically inclined).
I have read that the actual circuit breaker it uses is a 50 amp.
Thank you in advance of you answers!
I look forward to learning about the MS here on these forums.
 

brkaus

Well-Known Member
Jul 8, 2014
7,689
6,219
Austin, TX
2 together is still 100.

If it can handle a 50a breaker, that’s a different question. What other loads are in your house?

Also, how many miles do you drive per day, average & max?
 
Last edited:

drj400m

Member
Feb 3, 2018
48
12
MN
I have a washer, dryer (normal plug) and microwave and refrigerator. The stove, furnace and water heater is gas. It’s a smallish townhome.
I drive on average 30 miles per weekdays and 60 miles per day on weekends.
In my mind I think 23 miles/hr charge is possible if I’m reading the charts right.
 

Lloyd

Well-Known Member
Jan 12, 2011
6,256
2,048
San Luis Obispo, CA
New member so trying to jump in. I am currently looking at buying a MS and I have a question about charging set up at my home.
My current home circuit breaker has a door sticker stating max is 125 amps and I have the main breaker (2 breakers together with plastic showing 100 on each) that from what I can gather is 200 amps. So I’m unsure if breaker is 125 or 200.
Question is: can a 125 amp circuit breaker handle a NEMA 15-40 addition? I would have an electrician do the work (I am sure by the question you can tell not electrically inclined).
I have read that the actual circuit breaker it uses is a 50 amp.
Thank you in advance of you answers!
I look forward to learning about the MS here on these forums.

You need to have someone qualified to do a load analysis for you.
 

Need

Active Member
Nov 22, 2017
2,876
2,196
SoCal
When I had our outlet install, I contacted local electrician. He had me take a few picture of the main panel, asked me how far away I want the outlet, and gave me a quote within minutes after he got the MMS of the pics.
 

budosteve

Member
Dec 4, 2017
24
9
Cleveland, OH
You have 100a single phase service, and based only on your description you have the capacity to add a double pole 50a breaker.

Based on your planned energy consumption you can easily charge at 30a if you’re concerned about current draw.

LMK if you need to talk it out; happy to help.

Is your breaker panel within close proximity to your garage?
 

CameronB

Member
Nov 19, 2016
622
801
Los Altos, CA
You need to have someone qualified to do a load analysis for you.

Yeah, get a load analysis. If you have a 200 amp panel, likely there's some decent capacity available. If you have a 125amp panel, then likely will be tighter to try to find 'room' for a new 50A circuit. But...it all depends on the appliances, lights and other usage (say like a pool) you have. But it's also all the things you have plugged into all your outlets, not just classic appliances but also computers, stereos, TVs, etc. If you have a lot of incandescent or halogen lights..those use a lot more energy than if you had all LED lighting, for example. Energy Star appliances vs older, less-efficient ones, etc.

An electrician can do this for you pretty easily. Some do it more accurately than others. Mine was very detailed and wanted a full listing of what devices were used. In my case, I wanted to do a 90amp circuit - totally overkill and $$$. I did it for future proofing and maybe it will eventually be useful, but like you, I typically drive about 30-50 miles a day. I have a HPWC and although yes, even with the 'overhead' it could use the 72A that is the current max for any newish Tesla (though there were some classic ones that could handle 80A). Most Tesla's max out at 48A, but that's still plenty fast.

There are people more well versed in all the EV math than I am, but I believe your NEMA 15-40 on a 50A circuit (needed to get the full 40A because of overhead) would give you about 25ish miles per hour of charge.

With a High Performance Wall Charger (HPWC) at 48A, you would get about 32ish miles per hour of charge.

Even if you end up installing a 40A circuit (because not room for 50) and charging at 32A, it still means you'll recover your daily 30 miles in a few hours while you sleep.
 
Last edited:
  • Informative
Reactions: BrokerDon

2002A

Member
Jul 8, 2017
26
9
The Desert
I had the approved Tesla installer come out and give me an estimate before I ended up installed my 15-40 receptacle myself He looked at my electrical panels and the info tag inside the oven in the kitchen and was able to tell me per the app on his smartphone that I was OK for a 50 amp breaker. I got a few more estimates and after talking with the electricians I just decided to do it myself with about 85 dollars of materials. So I am running 240 volts with 40 amps on my 15-40 receptacle with a stainless steel cover. I get between 36 and 38 miles per hour on my 2016 90D.
 
  • Like
Reactions: BrokerDon

drj400m

Member
Feb 3, 2018
48
12
MN
Thank you for all the replies. This truly is helpful. I was somewhat down yesterday as I had thought that the “dream’ was over because I wasn’t going to be able to charge at home.

BTW budosteve I am having the plug within feet of the box. My box is currently in the garage on the left. Right where I would want to put the plug.
 

Brass Guy

Active Member
Jan 5, 2014
1,142
935
Holbrook, MA
You have a huge advantage that your larger appliances are gas. If you have central AC, I think that's usually a 30A 2-pole. That would be a big factor in your load calculation. If you don't have AC, it is very likely you'll be fine adding a 14-50.

My house has a 100A service, no AC, and gas water heater, stove and drier. I added the 14-50 to that.

I don't think they use 100A panels in any new construction any more; 200 or even 400 are more common now.
 

drj400m

Member
Feb 3, 2018
48
12
MN
Also, not sure this matters, I have a 1700 sq/ft townhome. My energy consumption per Excel is lower than “efficient” neighbors by quite a bit.
 

brkaus

Well-Known Member
Jul 8, 2014
7,689
6,219
Austin, TX
I have a washer, dryer (normal plug) and microwave and refrigerator. The stove, furnace and water heater is gas. It’s a smallish townhome.
I drive on average 30 miles per weekdays and 60 miles per day on weekends.
In my mind I think 23 miles/hr charge is possible if I’m reading the charts right.

Photo of your existing breaker panel?

It sounds very feasible and even if you have to go down to 30a breaker, you can charge at 24a and still get back 15-20 miles per hour of charging.

I would recommend an electrician if you have never worked with electricity before.
 

brkaus

Well-Known Member
Jul 8, 2014
7,689
6,219
Austin, TX
You mentioned gas water heater, but there is a breaker for water heater?

On the surface, looks to me like you easily have capacity. Exactly how much, I’m not sure.
 

brkaus

Well-Known Member
Jul 8, 2014
7,689
6,219
Austin, TX
You’re likely looking at about $50-80 in parts. Perhaps $150-300 labor. Plus permit if you go that route.

I’d call at least 2 electricians.
 

budosteve

Member
Dec 4, 2017
24
9
Cleveland, OH
Thank you for all the replies. This truly is helpful. I was somewhat down yesterday as I had thought that the “dream’ was over because I wasn’t going to be able to charge at home.

BTW budosteve I am having the plug within feet of the box. My box is currently in the garage on the left. Right where I would want to put the plug.

This is easy then. Very affordable. If you’re adventurous you can do it yourself.
 

About Us

Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.

Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


SUPPORT TMC
Top