Charging at 12amps

[ShortSell]

Based on Google, I read most outlets are max 15amps. My car charges at 12a from backyard plug.

I have to open and change the dial to increase Amp.

Now let's say I set Amp to 20 but outlet can only do 12, does that result in fire or something?

Like I'm not sure if I have 15amps. All I know is tesla only allowing me to pull max 12

 

[Solarman004]

A 15 amp circuit can only handle 15 x 0.8 = 12 amps continuous. This is the safety limit specified by code. So the car is doing the right thing by limiting the amperage to 12. If you use an extension cord (not recommended), the car may sense a voltage drop and limit the current even further. Don't try to override the settings. In theory, you will just trip a breaker, but in reality you might overheat and damage breaker, wires, plug, charge handle, etc.

 

[LoudMusic]

15A is peak rating at short bursts. For continuous operation Tesla limits all current draw to 80% of the circuit's rated output. This reduces the risk of overheating the wire and causing a fire.

 

[Solarman004]

@LoudMusic looks like we were typing at the same time ...

 

[ciuvak]

Is that receptacle a regular 120V outlet ? If you manually force the car to demand 15A from it, you will trip the breaker or/and overheat the wires, could potentially lead to a fire hazard.

 

[darkenergy]

Worst case is that you push the draw above the 80% nominal but below the trip level of the breaker. This would cause overheating and potentially lead to your house burning down.

The electrical code is there for a reason...

 

[ShortSell]

Ok I won't do anything silly lol.

But you guys have me scared.

What if the current plug supports less than 15a? Or that's very rare? It is a 2000s home.
Just want to be safe pulling 12a.

 

[Solarman004]

Ok I won't do anything silly lol.

But you guys have me scared.

What if the current plug supports less than 15a? Or that's very rare? It is a 2000s home.
Just want to be safe pulling 12a.

The circuit will be no less than a 15 A circuit so you don't have to worry. You can confirm this for yourself by looking at the label on the breaker for that socket. But if the house was built in the 2000s, barring a huge electrician mistake and an incompetent inspection, that socket will definitely be a minimum of 15 amps. (It's very unlikely that you will find any breaker in the panel less than 15 A)
You can safely charge at 12 amps for hours.
Of course there's always a caveat. Find out if the single breaker serves more than one socket (you can turn off the breaker and test the sockets in your garage). Don't try running a table saw at the same time you're charging if both are served by the same breaker.
Bottom line: charge at 12 amps without an extension cord and don't worry!

 

[CFinVancouver]

I set our Y to 11amps. I found at 12amps in our insulated garage the car was giving a warning that the plug was overheating. This tended to occur in the summer months. I think there is a temp sensor in the tesla mobile charger that senses this. Continuous draw of 12 amps on a 15amp was giving us this issue. The rolling green lights on the charger show a flashing red T when this occurs.

 

[jjgg]

I set our Y to 11amps. I found at 12amps in our insulated garage the car was giving a warning that the plug was overheating. This tended to occur in the summer months. I think there is a temp sensor in the tesla mobile charger that senses this. Continuous draw of 12 amps on a 15amp was giving us this issue. The rolling green lights on the charger show a flashing red T when this occurs.

Maybe the wires are not properly connected to the receptacle? I also charge from a 15A 120V outlet. I replaced the old receptacle with a heavy duty one and made sure the wire nuts were tight. I had no problems charging at 12 Amps for over 16 hours continuously.

 

[Tronguy]

I set our Y to 11amps. I found at 12amps in our insulated garage the car was giving a warning that the plug was overheating. This tended to occur in the summer months. I think there is a temp sensor in the tesla mobile charger that senses this. Continuous draw of 12 amps on a 15amp was giving us this issue. The rolling green lights on the charger show a flashing red T when this occurs.

Agree with the previous poster. Most likely cause is an old or loosely connected socket. Sockets can and do get physically worn out with use and age, complete with broken plastic bits, letting the smoke out, flashes of light, and breaker popping; has actually happened to me.
Turning off the breaker for this socket, verifying with a voltmeter or some such that that’s actually the case, then unscrewing the faceplate and mounting screws and hauling the socket out of the box for an inspection would be a good idea. If anything is singed looking, or if it’s more than a decade old, replace the thing with a new one, they’re cheap. And much cheaper than a fire department with smoke and flame damage.
Final note. It’s been code for a while that the single breaker for a single 120VAC outlet in a garage be 20A. If that’s true for your place, the breaker will be labeled 20 and the socket will be a NEMA5-20, with a bit where one of the blades can be at right angles to the other one.

• If neither of those is true, make sure that, if you replace the socket, you put in a NEMA5-15, with no optional right angle blade. Safety first! Breaker, wire and socket should match for current rating!
• If you do have a 20 amp breaker, put in a NEMA5-20 20 amp socket with that right angle bit on one of the blades. Further, if that’s your setup, you can get a NEMA5-20 adapter for your mobile cable, at which point the car will charge at 16A, rather than at 12A with the NEMA5-15 adapter that comes with the car. That might not sound like much, but your car will charge at 6.5 to 8 miles an hour rather than 5 to 6.

 

[Soul Surfer]

I think our building gave me a 40amo circuit for my J-1772 L2 charger. My L2 is a 25 amp Clipper Creek/Sun Country Highway, which means that at 80%, I can run at a max of 20amps. I usually charge at 12amps as I'm not in any rush and have way more capacity in the "tank" than I use.