Home charging newb - please help

[FormationLap]

New to Teslas, and my first post, excuse the beginner questions.

I've reached out to electricians for quotes on setting up home charging, they've all told me after looking at my electrical panel, that the biggest breaker they could install and pass inspection, is 30 or maybe 40 amps.
Got super excited when I got a delivery date and ordered the wall connector without doing proper research. Hasn't arrived yet, and now thinking I might want to install a 14-50 receptacle instead.

1. Given my breaker limitations, would there be any charging speed differences between the wall connector and the cord that came with my car with a 14-50 adapter?
2. Is there be any charging speed difference between the cord that came with my car with a 14-50 adapter and the corded mobile connector that comes with a 14-50 plug (going for $691 CAD on Tesla Shop)?
3. If I decide to return the wall connector, can I do that at my local Tesla dealership?

If the speed differences aren't huge between the wall connector and a 14-50 plug, I'm thinking of returning the connector ($635 CAD) and just picking up a ($45 CAD) 14-50 adapter. I don't see too much need of taking the cord with me, but if in the future I do find myself packing it up often, I might spend the money and get the corded 14-50 plug. Or might buy it if there are significant speed gains.

Thanks your help.

This car is incredible.

 

[Saghost]

The car has no way of knowing what breaker is installed. It relies on the EVSE to tell it how much power to pull. (Though Tesla gives you the ability to manually adjust the limit down from there, and attempts to remember those changes by location.)

Under US electric code, the car can’t use more than 80% of the rated line power for charging (same for any “continuous load.”)

So with a 30A breaker, you need a 24A limit and with a 40A breaker a 32A limit.

The UMC is limited to 32A max regardless, even with the 14-50 plug. If you end up with a 30A breaker, you could have a 14-30 outlet (standard modern dryer plug,) installed and get the 14-30 pigtail from Tesla, which will cause the UMC to pass a 24A limit you the car.

The Wall Connector has a switch inside it that’s set on installation which will tell the car the limit.

The corder mobile connector will tell the car to charge at 40 amps, which really isn’t appropriate for your situation. You could turn the car down manually, but there’s a risk of something going wrong with that.

 

[gfunkdave]

Unless you're driving hundreds of km a day and need the car fully charged early each morning, you don't need a 50A charging connection. Install a 30A and enjoy your new car.

 

[Rocky_H]

I've reached out to electricians for quotes on setting up home charging, they've all told me after looking at my electrical panel, that the biggest breaker they could install and pass inspection, is 30 or maybe 40 amps.
Got super excited when I got a delivery date and ordered the wall connector without doing proper research.

I think there is a confusion you have about the wall connector where you are making this way harder on yourself than you need to.

You said that you have ordered the wall connector, but then when you found out that you can only install up to about a 30 or 40 amp circuit, you seem to be disappointed and defeated and are talking about returning it and looking for other alternatives. Some people think that the wall connector MUST be installed on ONLY a 60A circuit. Is that what you were thinking?

The wall connector is a dynamic device that can be configured for many different levels of circuit, like 15, 20, 25, 30, 40, 50, or 60. So I would say don't fret about anything else. Just get a 30 or 40 amp circuit or whatever fits well within your house's electrical system, and install the wall connector and be happy!

 

[FormationLap]

Thanks everyone! I took delivery of the wall connector and sent it back to Tesla. Separately I ordered a 14-50 adapter. I'm planning on getting the 14-50 receptacle installed and using the mobile connector to charge up.

The corder mobile connector will tell the car to charge at 40 amps, which really isn’t appropriate for your situation. You could turn the car down manually, but there’s a risk of something going wrong with that.

What's the risk? If anything it would be getting fewer amps than it can handle, is that a problem?

Unless you're driving hundreds of km a day and need the car fully charged early each morning, you don't need a 50A charging connection. Install a 30A and enjoy your new car.

That's the plan!

The wall connector is a dynamic device that can be configured for many different levels of circuit, like 15, 20, 25, 30, 40, 50, or 60. So I would say don't fret about anything else. Just get a 30 or 40 amp circuit or whatever fits well within your house's electrical system, and install the wall connector and be happy!

Returned it to save the $635 CAD

 

[Saghost]

Thanks everyone! I took delivery of the wall connector and sent it back to Tesla. Separately I ordered a 14-50 adapter. I'm planning on getting the 14-50 receptacle installed and using the mobile connector to charge up.



What's the risk? If anything it would be getting fewer amps than it can handle, is that a problem?

The risk isn’t damage to the CMC - it’s damage to everything else.

The risk is that at some point the car forgets it was turned down (like one of the firmware updates that reset the GPS system so all the cars thought they were at Tesla headquarters until they got driven for a few minutes, so it isn’t in the geotagged location even though it hasn’t moved,) and the car then tries to draw the 40A that the box is telling it the car can have - at which point if you’re lucky the breaker pops.

If you aren’t, and the electrician sized the wire run to match the breaker, the wiring starts to overheat.

The car has programming that watches for excessive voltage drop and will hopefully react in that situation, but you really don’t want to be dependent on it.

 

[FormationLap]

The risk isn’t damage to the CMC - it’s damage to everything else.

The risk is that at some point the car forgets it was turned down (like one of the firmware updates that reset the GPS system so all the cars thought they were at Tesla headquarters until they got driven for a few minutes, so it isn’t in the geotagged location even though it hasn’t moved,) and the car then tries to draw the 40A that the box is telling it the car can have - at which point if you’re lucky the breaker pops.

If you aren’t, and the electrician sized the wire run to match the breaker, the wiring starts to overheat.

The car has programming that watches for excessive voltage drop and will hopefully react in that situation, but you really don’t want to be dependent on it.

That makes complete sense.
Thank you!

So if the electrician is able to get me a 40 amp breaker, go with the 14-50. If he can only get me a 32 amp breaker, go with the 14-30?

 

[gfunkdave]

That makes complete sense.
Thank you!

So if the electrician is able to get me a 40 amp breaker, go with the 14-50. If he can only get me a 32 amp breaker, go with the 14-30?

There's no such thing as a 32A breaker. A 14-30 will be on a 30A breaker by definition (the "30" in 14-30)

 

[Rocky_H]

@FormationLap And you can have a good solution for either of those: a 40A or a 30A circuit.

With a 40A circuit, a 14-50 receptacle is allowed as a specific exception in electric code because there is not a 40A outlet type. A lot of ovens are set up that way. And the regular Tesla mobile connector can only do maximum 32A anyway, which is the appropriate level on a 40A circuit. So you would buy the 14-50 adapter for your cord.

Or if you get a 30A circuit, then you put a 14-30 outlet on there, and you buy the 14-30 adapter from the Tesla store, and that will properly sent the current to 24A, which is right for a 30A circuit.

 

[SSonnentag]

I think there is a confusion you have about the wall connector where you are making this way harder on yourself than you need to.

You said that you have ordered the wall connector, but then when you found out that you can only install up to about a 30 or 40 amp circuit, you seem to be disappointed and defeated and are talking about returning it and looking for other alternatives. Some people think that the wall connector MUST be installed on ONLY a 60A circuit. Is that what you were thinking?

The wall connector is a dynamic device that can be configured for many different levels of circuit, like 15, 20, 25, 30, 40, 50, or 60. So I would say don't fret about anything else. Just get a 30 or 40 amp circuit or whatever fits well within your house's electrical system, and install the wall connector and be happy!

This is your best solution, being the safest and most convenient. This allows you to keep your mobile connector in the car for when you may happen to need it when out and about on a trip. You don't want to be plugging and unplugging the mobile connector every day as the plug and socket will wear out and become a fire hazard. If you leave the mobile connector plugged in at home all the time you won't have it available for an emergency situation while away from home. In my opinion, the safety and convenience of having the Tesla HPWC is well worth the $700. As Rocky_H said, the HPWC has dip switches in it that limit the amount of power the unit can provide, thus removing any change of over-draw on the part of the car.

 

[FormationLap]

Appreciate all the help, will wait to see what breaker I'm approved for, 30 or 40 amps, and will either go for the 14-30 or 14-50 breaker.

Thanks!

 

[Rocky_H]

It's funny you're "agreeing" with me, but I disagree with most of that.

This allows you to keep your mobile connector in the car for when you may happen to need it when out and about on a trip.

Keeping it in the car all the time is really not necessary. People prepare and pack when they are going out of town on a trip. Grab it then when you're going to travel if you want to.

You don't want to be plugging and unplugging the mobile connector every day as the plug and socket will wear out and become a fire hazard.

Well yeah, but people don't need to unplug it every day. As someone on this forum is fond of saying, that word "mobile" is a capability--not a requirement. It is perfectly normal for the UMC to stay hanging on the garage wall all the time as a permanent charging setup. I've been going over 6 and a half years that way.

If you leave the mobile connector plugged in at home all the time you won't have it available for an emergency situation while away from home.

It is pretty nearly unheard of that someone would just magically, suddenly "find themselves" out in the middle of nowhere and not near any public charging and needing to plug into an outlet.

In my opinion, the safety and convenience of having the Tesla HPWC is well worth the $700. As Rocky_H said, the HPWC has dip switches in it that limit the amount of power the unit can provide, thus removing any change of over-draw on the part of the car.

I only suggested using it because he already had it, so I thought he originally did want it for some reason and was just mistaken in thinking it couldn't be used with the level of circuit that would be available.