Adding a 2nd Tesla home charger and tapping the wires.

[eswimm]

Both options, daisy chained or separate runs are perfectly safe if done correctly. Fewer components and shorter wire runs are inherently safer and cheaper than more wire and more potential points of failure (components). The electrician who suggested a 90A breaker is wrong, either because they didn't understand what was needed or they don't know what they're doing.

If the 2nd wall connector is closer to the 1st wall connector than to the panel, then daisy chaining likely makes sense. If a home run would be shorter, then that is the best option. Daisy chaining requires group management, since breaker and wire max is 60A (48A charging). Home run only requires group management if you need to limit the concurrent draw to avoid overloading your panel(s). I have a 320A service (2 200A panels) and operate 2 60A wall connectors, a NEMA 14-50 for a 40A JuiceBox and a NEMA 6-20 for my motorcycle; all at once without issue, but I have gas heat, hot water and cooktop. If you have a 100A service or a 200A service with high draw electric devices (water heater, cooktop, hot tub, electric heat, etc) then group management can help.

What matters most is that the electrician uses the proper equipment for the job and knows what they're doing. Basic things like doubling up wires in a terminal rated for only one conductor instead of using a properly rated multi-tap may save a little time and dollars, but can lead to serious problems over time.

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[carsly]

I have the lectron splitter - it has been working fine for me, might work for you. I just added pigtails to the tesla charger and plugged it in.

Lectron

This is what I did, pretty simply and I like having an extra breaker in between.

 

[Mikec3399]

My opinion, change to a 60amp breaker and light it up!
You control the charging in your app, at a 15amp draw on each vehicle, at the same time would be my test.
if not, then run a separate circuit, outside and have peace of mind and never worry about home charging overloads again

I'm just a General Contractor, so what do I know.

 

[That Beast Mode]

This makes no sense.

Obviously he doesn’t understand that the UWCs are smart, and can limit their collective current.

Regardless, you can’t magically turn a 50A circuit into a 90A circuit by swapping the breaker. If you pull 90A through 6AWG then the melting wire becomes the breaker lol.

This was my thought exactly.. the romex wire is rated for something like 58A... regardless of knowing they are smart chargers or not, he should know better than this

 

[That Beast Mode]

The UWC is designed to be safely daisy-chained, using Group Management to ensure the circuit capacity is never exceeded.

But can you link UWCs when using PowerShare?
Asking for a friend

The daisy chain thing is what i mainly wanted to know and do.. I dont have a powershare setup anyway so I wouldnt be able to answer that.

 

[That Beast Mode]

This is what I did, pretty simply and I like having an extra breaker in between.

If i had an outlet I would certainly go this way. My current one is hard wired.

 

[Thunderstrike44]

If the Wall box can talk to each other and Limit your total draw on the circuit, but you are still taking a chance if that system ever fails and both are on at the same time. I would run to circuits if it was me. Assuming you are on a regular 200A Service , that's going to be almost 100A when do both at the same time. Or you reduce the level of each so they are limits to 1/2 your full circuit then you never have to worry about it. Regardless how this circuit may "Share" the power it still will only charge you cars at the limit of the circuit. So if you are at 48A each car will only get 24A max effect power. Sorry if I am getting too technical, Old Electrical Engineer here .

 

[That Beast Mode]

My opinion, change to a 60amp breaker and light it up!
You control the charging in your app, at a 15amp draw on each vehicle, at the same time would be my test.
if not, then run a separate circuit, outside and have peace of mind and never worry about home charging overloads again

I'm just a General Contractor, so what do I know.

The romex wire is rated to i believe 57A. Can you push the limit with a 60A breaker, maybe. Id rather not find out the answer the hard way though. I purposely had the breaker under rated at 50A. Id rather slower charging and be safe than sorry. The Tesla charger will manage things on its end, but id prefer knowing there is an extra layer of protection.

 

[Jhodgesatmb]

This makes no sense.

Obviously he doesn’t understand that the UWCs are smart, and can limit their collective current.

Regardless, you can’t magically turn a 50A circuit into a 90A circuit by swapping the breaker. If you pull 90A through 6AWG then the melting wire becomes the breaker lol.

I am surprised that the OP is using Romex for their wall connectors. Isn’t that the wrong wire gauge for EV charging? It works for household appliances because they have lower sustained current requirements. I should think the safest approach is a dedicated subpanel off the main with lower-gauge wire. I am not an electrician but we have had some very suspicious ’electricians’ and I used one with a lot of experience wiring for EVs. Our wall connectors are on separate 60-amp breakers in a separate subpanel from the house.

 

[That Beast Mode]

If the Wall box can talk to each other and Limit your total draw on the circuit, but you are still taking a chance if that system ever fails and both are on at the same time. I would run to circuits if it was me. Assuming you are on a regular 200A Service , that's going to be almost 100A when do both at the same time. Or you reduce the level of each so they are limits to 1/2 your full circuit then you never have to worry about it. Regardless how this circuit may "Share" the power it still will only charge you cars at the limit of the circuit. So if you are at 48A each car will only get 24A max effect power. Sorry if I am getting too technical, Old Electrical Engineer here .

No no, not too technical - this is the feedback I asked for, I appreciate it. Yes I agree with you. I honestly dont want to have them both running at the same time, that's why im avoiding the second line option. Id rather it do power management like others suggested and if there was a flaw in the system and they both turn on at full blast for some reason then trip the 50A breaker. I dont want it drawing 100A.

 

[Korben Dallas]

I have Romex wire in my garage on a 50A breaker currently for my Tesla wall charger.

What wire gauge is the Romex? I assume it’s 6-gauge copper NM wire per NEC.

 

[That Beast Mode]

I am surprised that the OP is using Romex for their wall connectors. Isn’t that the wrong wire gauge for EV charging? It works for household appliances because they have lower sustained current requirements. I should think the safest approach is a dedicated subpanel off the main with lower-gauge wire. I am not an electrician but we have had some very suspicious ’electricians’ and I used one with a lot of experience wiring for EVs. Our wall connectors are on separate 60-amp breakers in a separate subpanel from the house.

The house was pre-wired for an EV in the garage by the prior owner with Romex 6g. From my (limited) understanding of this, it is fine to use but not on a 60A like a true 6g wire. Because romex is rater slightly lower than 60A, which is why I have it on a 50A breaker instead so it cant possibly overload the wires.

 

[Jhodgesatmb]

The romex wire is rated to i believe 57A. Can you push the limit with a 60A breaker, maybe. Id rather not find out the answer the hard way though. I purposely had the breaker under rated at 50A. Id rather slower charging and be safe than sorry. The Tesla charger will manage things on its end, but id prefer knowing there is an extra layer of protection.

Whatever the breaker or wire is rated at you can only use 80% of that, and you have to drop to the next level down. If Romex is rated at 57 amps max, then the next level down is 48, and 80% of that is more like 40 amps. Can an electrician say whether this is correct? As I mentioned earlier, my understanding is that Romex is for household appliances and not for constant high-amperage draw.

 

[That Beast Mode]

What wire gauge is the Romex? I assume it’s 6-gauge copper NM wire per NEC.

Correct.

 

[Mikec3399]

The romex wire is rated to i believe 57A. Can you push the limit with a 60A breaker, maybe. Id rather not find out the answer the hard way though. I purposely had the breaker under rated at 50A. Id rather slower charging and be safe than sorry. The Tesla charger will manage things on its end, but id prefer knowing there is an extra layer of protection.

then I would stay with the 50 amp, fires are devastating
slow charge is better for battery life
manage the charging in the app, like i do
i home charge with two 2024 FS Cyberbeasts, currently one charger, TESLA ABC's always be charging!
I just ordered two New Gen 3 wall charges to connect with my power share,
my plan is to install two power share units, and two wall chargers for two cyberbeasts, I do have a
6043 Sq foot home in Georga, that has two GE Panels,
next year ill start my installation, first without solar, see what efficiencies I can produce, I do have Free Lifetime supercharging, on One Beast,
if I do not get a lower electric bill, Ill add solar panels,
I currently Charge at My home in Connecticut, with Solar, so I always have one truck charging in the day light.
I am considering adding a second charging cord, like your adding, but i am weighing the cost. I'll be moving permentaly to GA in 2027 so moving the cord from truck to truck is fine

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