10-50 outlet for charging

[propose1999@gm]

Hello
this is my first question in this motor group.
i have a 10-50 outlet at Garage and want to charge it for tesla... my question is

which adapter do i have to use it using our current circuit breaker (see the following email)

1. charging cable with 14-50 adapter + 10-50 to 14-50 adapter (operating current 32amp)
or
2. charging cable with 14-30 adapter(30amp) + 10-50 to 14-30 adapter


please help me .. thanks.

 

[exxxviii]

You are in an odd no man's land... Your outlet is rated for 50A, but it is on a 45A breaker. So, you do not know if the wiring is rated for 45A or 50A. And Tesla does not make an adapter rated for 40A (thought they down-rate the performance of the 14-50 and 6-50 plugs as if they were on a 40A circuit).

I would be tempted to convert the outlet to a 14-30 and then change the breaker to a 30A GFI. You give up about 2 kW of charge rate, but that is the easy button.

The other side is if you can confirm that the wiring is sufficient to truly support a 50A circuit, then I would convert it to a 14-50 outlet and replace the breaker with a 50A GFI.

 

[ATPMSD]

The 10-50 does not have a neutral, so you cannot use anything that needs one, such as a 14-50. You can change the outlet to a 6-50, which is the newer 240v 50A outlet. With a 45A break you can (must) just label the outlet as 45A.

If you are using a mobile connector then a 6-50 Tesla adapter for the mobile connector should be fine since the mobile connector is internally limited to 32A. The new 6-50 outlet will run you about $80, a GFCI breaker (required by code) is about $150, the mobile connector is $230 if you do not already have one, $45 for the Tesla 6-50 adapter, and say $35 for some sort of cable management system.

On the other hand, if you buy and install a wall connector, it is $425 (price just increased) and you can keep your breaker. You will set the connector to a 40A circuit and it will charge at 32A. If you inspect the wire and determine it can handle 50A, then you can configure the wall connector to a 50A circuit and charge at 40A.

 

[ATPMSD]

GFCI breaker (required by code)

Before someone chimes in to say you don't need the GFIC breaker (with the mobile connector option), let me expand. Given the outlet is a 10-50 I assume this is an old circuit. Generally, you do not have to meet a revised electrical code unless you make a change. I am not an electrician and cannot comment as to whether changing the outlet from 10-50 to a 6-50 is a sufficient change. I will offer, however, that the code was changed for good reason.

 

[jcanoe]

The 10-50 does not have a neutral, so you cannot use anything that needs one, such as a 14-50.

What am I missing here? Diagram shows 10-50R wiring the same as the 10-30R; Hot, Hot, Neutral, no Ground.

Common Household NEMA Receptacles Diagram

 

[ATPMSD]

What am I missing here? Diagram shows 10-50R wiring the same as the 10-30R; Hot, Hot, Neutral, no Ground.

Common Household NEMA Receptacles Diagram

Well darn, you are right! But as you noted the 10-50 (and the 10-30) does not have a ground, and there is no Tesla adapter for it. So this makes for interesting wiring for the replacement as the existing “neutral” will need to be converted to a ground.

Good catch!

 

[jcanoe]

Well darn, you are right! But as you noted the 10-50 (and the 10-30) does not have a ground, and there is no Tesla adapter for it. So this makes for interesting wiring for the replacement as the existing “neutral” will need to be converted to a ground.

Good catch!

You can purchase a 10-50 power plug adapter for the Tesla Gen2 Mobile Connector from EVSEAdapters.com

 

[SageBrush]

I'm not sure if the white colored wire may be re-identified as a grounding conductor but if yes, OP has an easy solution

The odd thing (to my mind, anyway) is that if the branch circuit has its breaker in the main load center, the neutral and ground are already bonded. So this is not a technical question, but a NEC convention question