My main breaker is 100A. I understand my electrician can do load calculations for a charger, I'm thinking of getting the Model 3 Standard Range Plus so I would only need the 40A breaker. My main panel is an older 100A breaker, but assuming 40A will be too much load with the rest of my breakers, is there any other options I'll have available other than an entire new 200A breaker or less amperage breaker for the charger?
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Kimmi
Member
My house has 100amp service. 50amp breaker the 3 LR & 40amp for the A/C. My A/C & Gen 3 Tesla Wall Connector work fine.
Why do you think you need a 40 amp circuit. A NEMA 1430 ( 30 amp) would be more than enough to recharge the car overnight.
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Gen 2 NEMA Adapters
Use a variety of household outlets to charge your Tesla with a Gen 2 NEMA Adapter. Simply attach the appropriate adapter to your Mobile Connector, plug into the corresponding outlet and begin charging. Adapter Max Distance Gained Per Hour of Charge Model S Model 3 Model X Model Y 5-15 3...
shop.tesla.com
I've considered a NEMA, but I recently was given a Tesla wall charger from a friend, so I figured I might as well put it to use.Why do you think you need a 40 amp circuit. A NEMA 1430 ( 30 amp) would be more than enough to recharge the car overnight.
Gen 2 NEMA Adapters
Use a variety of household outlets to charge your Tesla with a Gen 2 NEMA Adapter. Simply attach the appropriate adapter to your Mobile Connector, plug into the corresponding outlet and begin charging. Adapter Max Distance Gained Per Hour of Charge Model S Model 3 Model X Model Y 5-15 3...
Could you add another 30-, 40-, or 50-amp run directly from the meter, and run that to a dedicated 14-50 outlet or to a hard-wired wall-mount charger? Effectively a mini "sub-panel" dedicated to your EVSE/charger. You'll of course need a meter and service drop capable of providing 130 - 150 amps. This wouldn't impact the 100 amps going to your current panel.
Don’t make an assumption about how much current you can charge with; the electrician will be more than happy to figure that out for you.
If you have a wall chargers that you’re gonna use, there are a lot of choices you simply don’t have to make. Hand it to the electrician, tell him you want the maximum current that your box will support, and be happy. You don’t want to say “limit it to 40A because that’s all my current car will use”; next year you may have a different “current car”.
If you have a wall chargers that you’re gonna use, there are a lot of choices you simply don’t have to make. Hand it to the electrician, tell him you want the maximum current that your box will support, and be happy. You don’t want to say “limit it to 40A because that’s all my current car will use”; next year you may have a different “current car”.
I'm really confused why you are asking for options then. The wall connector can be set for whatever level of circuit it's on, from 15A up to 60A. So you will get a load calculation, find out how big a circuit you can add, and then set the wall connector for that. There aren't really any options or choices you need to consider if you're already going to use a wall connector.
You can set the wall connector to a lower amperage when you set it up. Go down to 30A if you need to.
Dmagyar
Member
Wow, that’s quiet the pricy addition for a job that basically is done for nothing by the existing circuit breaker feeding any charging circuit. As that said charging circuit will already have been limited to 80% as it’s considered a continuous load, one that runs for over three hours. The larger misunderstanding here is that any 100 amp service is actually the sum of 100 amps each hot leg (two) for a total of 200 amps (though this proposed charging circuit will reside on each “hot leg” adding it’s load). With benefit of a load calculation an Electrician can figure what size circuit your existing panel set up can handle, saving the $1,000.00 plus this pesky installation costs for the DCC-10. Imho. Plus there’s diversity where all the connected loads in a household situation aren’t running together continuously.
It would be pointless to install a DCC-10 if you didn't need it ... if the load calculation for a service exceeds the allowable limits, a load shedder is the only real option. Ignoring code and popping breakers is not a real solution.
I have to charge two Tesla's on a 100A service and use the DCC-10 to prevent overloads and a Neocharge splitter to control which car gets charged. It works well and is a lot less expensive than upgrading a panel, if that was even an option.
I have to charge two Tesla's on a 100A service and use the DCC-10 to prevent overloads and a Neocharge splitter to control which car gets charged. It works well and is a lot less expensive than upgrading a panel, if that was even an option.
Dmagyar
Member
Uhh, no. That’s not the way it works.
TheRFMan
Member
A 100A panel may be able to easily accommodate a 40A circuit. It really depends on what other loads you have on there. If some or all of your main appliances (stove, water heater, dryer) run on gas, you may not be using much of your 100A capacity.
You’re right about pricey.
But no, your main breaker does not trip at 80% nor does it turn itself back on. it might warranted for some folks in condo situations where it’s not so easy to upgrade your service and they are maxed out.
It was a good suggestion that could make the difference for some folks.
It’s rare you can’t safely squeeze in a 240V 20A circuit which is plenty. Especially for Model 3.
Another option folks rarely consider is upgrading an appliance or two. For example I just had a well installed and my Panel is pretty maxed out. Electric heat, Electric Hot water, Electric Stove, and EV. I could install a conventional 2HP pump. It pulls 12A 240V. But it can surge up to 36 Amps! when it starts. Or I can buy a more advanced pump with a 3 phase variable speed motor. It has no surge and only pulls 8 Amps. Problem solved.
I’m also removing electric heat and replacing them with a high efficiency heat pump. They take 1/4 watts. Cost peanuts to replace too because of incentive rebates.
100A panel is plenty with efficient appliances. Except for EV (new appliances) your electricity needs should be going DOWN not up.
Dmagyar
Member
Dmagyar
Member
I certainly didn’t mention the main breaker tripping at 80% of it’s rating...the main breaker may not trip at 130% or more of it’s rating, it’s condition, how many times it’s been exercised will influence it’s trip point...imho.
Let's take an example. You turn on your flashlight, causing a 1 amp current draw. This means that there's 1 amp going through the positive wire of the lightbulb, and 1 amp going through the negative wire of the lightbulb, for a total of 2 amps.
Is this correct? How is this example different than your original statement:
I think what you're trying to get at is that 100 amp, 240V service (in the USA) can be used as 200 amp, 120v service providing that the circuit breaker box is wired precisely and the loading is done precisely. But that's a somewhat degenerate use case.
Dmagyar
Member
I see how my statement was misinterpreted, but by no means does it make this statement by yourself true...There would be only one amp flowing in your imaginary flashlight circuit... My statement was just for those not too informed as to the total wattage draw they would experience with that noted 100 amp service. Obviously any 240 volt loads are connected to both hot legs and would be calculated as such to the overall total capacity of said panel. P=I*E(excluding power factor)
