5-15 Charging at 5-20 socket

[theredviper]

Dumb question. If I'm plugging in to a wall socket that is 5-20 but I only have the 5-15 included adapter, can I manually push up the current to 16A or will the adapter not allow me?

Is there really a different wire gauge in the 5-20 plug?

 

[ItsNotAboutTheMoney]

I believe* there's a resistor in the adapter that's used to limit current.

* I searched and found references in posts on TMC.

How do adapters signal max amperage to UMC?

 

[noam]

Dumb question. If I'm plugging in to a wall socket that is 5-20 but I only have the 5-15 included adapter, can I manually push up the current to 16A or will the adapter not allow me?

No, you are limited to 12A with the 5-15 plug adapter.

Is there really a different wire gauge in the 5-20 plug?

No. Tesla limits the amperage draw (I believe with a resistor to signal to the unit the type of plug) for safety.

 

[Rocky_H]

If I'm plugging in to a wall socket that is 5-20 but I only have the 5-15 included adapter, can I manually push up the current to 16A or will the adapter not allow me?

Each Tesla adapter does have a differently sized resistor inside that the mobile charge cable can read. It uses that to determine a maximum number of amps allowed. It's a pretty clever system.

Is there really a different wire gauge in the 5-20 plug?

Well, different than what? If it does have a 5-20 outlet on it, it's required to have wire at least capable of handling that. Like kitchen countertop outlets are required to be 20A circuits, because they may be using microwaves and toaster ovens and other high current loads. If you see a 5-15 outlet, that might be a 15A circuit with thin wire, or it might be a 20A circuit with thicker wire--they are allowed to put either outlet type on it, so sometimes builders put the cheaper 5-15 outlets on in some places.

 

[eprosenx]

Is there really a different wire gauge in the 5-20 plug?

To expand on your comment: I own both the 5-15 and the 5-20 adapter. I have not looked at them side by side and on the label to see what gauge wire they used. You are right, they likely do use the same gauge wire. The difference being that they have two different resistors in them (these are not inline with the power, they are just on signaling pins to tell the UMC which kind of adapter is plugged in which it then signals to the car not to charge with too many amps).

So if you could somehow override the resistor or the J1772 signaling to the car and turn up the amps, there is a good chance nothing bad would happen since the wire might be the same gauge and the metal contacts in the plug might be of sufficient ampacity even in the 15a version of the plug to handle 20a, but you really really don't know. I would not try to find out myself. I bought the 5-20 as well for the $35.

I also do have a cheater adapter that lets me plug the 5-20 UMC adapter into a 5-15 outlet. This is against code and in some cases could be a safety hazard (say if it really is only a 15a circuit - or say the 15a receptacle even on a 20a circuit might not have enough clamping force to carry the full 20a on the receptacle), but it is useful in some scenarios where I can actively monitor the heat, etc... I can not recommend this solution to others, though I do simply call out that these adapters do exist. I think somewhere I have found pictures of a teardown someone did of a 5-15 and a 5-20 receptacle from the same manufacturer and they found that they were literally identical inside. The 5-15 just had plastic molded in such a way that you could not insert a 5-20 plug into it. All the metal bits were the same.