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[Crissa]

Yeah, it's old behavior to expect loads to be split over more than one outlet.

However, it would be fine to charge the Zero off the EVSE.  Or have EVSEs set to lower than the circuit rating plugged into the circuit (because they're not outlets, per se).

-Crissa

[hein]

It’s my understanding that the circuit breaker must protect the max rating of the lowest amp draw device (outlet), so that 50 amp circuit breaker would have to be replaced with a 20 amp breaker if a 20 amp outlet was installed on that circuit.

Noop.
The breaker protects the wiring, not the outlets.
Think about your house.
How many outlets in the kitchen alone, each rated 15 Amps? 8+ ?
How many breakers? My guess is just 1 at 20 Amps, all outlets being fed from the same 12 Awg copper romex for sure.

 mdjak1>> "Alright, you convinced me.   But I added a new 20A, 220V circuit to the subpanel in my garage rather than connecting to the 50 amp I use to charge my car."

If you have to panel right there, and a spot for a breaker than yes for sure, add the breaker!
Well done.

[DonTom]

Don, can you please provide a documentation that states you can have an outlet that is rated less then the breaker that protects it.

That is the norm everywhere, AFAIK. Ask any electrician about the 80% rule.

For an example, I had an electrician put in my Tesla Wall connector here. It is on a 60 amp circuit breaker. 60 amp wiring. The Tesla Wall Connector is rated at 48 amps max and no other equipment can be tied to that circuit.

60 amps times 80%=48 amps.

Same in one of my other houses where I had a NEMA 14-50R added. It's also on a 60 amp breaker, 60 amp wiring, 48 amp max at outlet.

I am not an electrician, but I do know about the 80% rule being code everywhere I have had any work done. And that includes CA as well as here in NV.

So can you should me documentation where it is allowed to draw 60 amps from a 60 amp breaker?

In fact, 120 VAC outlets in the USA. They are all on 20 amp CBs with 20 amp wiring.  But the plugs are normally rated for 15 amps. 

Again, 20 amps minus 80%=16 amps max allowed.

At my house in Cold Springs Valley, NV, I had a 14-50R installed by a licensed electrician. Also on a 60 amp breaker. 14-50R is rated at 50 amps, not sixty.

-Don-  Reno, NV

[ESokoloff]

It’s my understanding that the circuit breaker must protect the max rating of the lowest amp draw device (outlet), so that 50 amp circuit breaker would have to be replaced with a 20 amp breaker if a 20 amp outlet was installed on that circuit.

Noop.
The breaker protects the wiring, not the outlets.
Think about your house.
How many outlets in the kitchen alone, each rated 15 Amps? 8+ ?
How many breakers? My guess is just 1 at 20 Amps, all outlets being fed from the same 12 Awg copper romex for sure.

 mdjak1>> "Alright, you convinced me.   But I added a new 20A, 220V circuit to the subpanel in my garage rather than connecting to the 50 amp I use to charge my car."

If you have to panel right there, and a spot for a breaker than yes for sure, add the breaker!
Well done.

Please provide NEC  https://en.wikipedia.org/wiki/National_Electrical_Code
documentation that states a 20 amp outlet can be installed downstream of a 50 amp circuit breaker?


The OP elected to run a dedicated 20 amp circuit from the main panel but he could have installed a sub panel from the 50 amp feed & run a proper 20 amp circuit from it (protected with a 20 amp breaker).

[DonTom]

Don, can you please provide a documentation that states you can have an outlet that is rated less then the breaker that protects it.

I just looked it up, see here.

-Don-  Reno, NV

[ESokoloff]

Don, can you please provide a documentation that states you can have an outlet that is rated less then the breaker that protects it.

I just looked it up, see here.

-Don-  Reno, NV

While that info is helpful to me for reasons outside of this discussion (& I thank you for it), it has nothing to do with the Legality (code) of installing a 20 amp outlet on a 50 amp circuit. 

[Crissa]

I think you can only do it if it's labeled.

But the presumption is that anything on that smaller amperage outlet will be protected by a smaller amperage breaker.

-Crissa

[hein]

Noop.
The breaker protects the wiring, not the outlets.

Please provide NEC  https://en.wikipedia.org/wiki/National_Electrical_Code
documentation that states a 20 amp outlet can be installed downstream of a 50 amp circuit breaker?

Thank you Eric,
This is all 2005 NEC. 210.21 Outlet Devices material correct?
I should not comment on that without thorough understanding.
Or as someone wrote https://www.bobvila.com/posts/82844-15-amp-outlets-in-a-20-amp-circuit more bluntly  "Don't listen to him unless you want to burn your house down. "
It seems a 20 Amp receptacle should be protected with a 20 Amp breaker.
The only exception being multiple 15 amps on a 20 amps circuit
I haven't found a perfect URL  for the exact NEX 210.21 wording.
This seems to come close: https://www.ecmag.com/section/codes-standards/code-focus-article-210-branch-circuits


Thanks,
Hein

[DonTom]

While that info is helpful to me for reasons outside of this discussion (& I thank you for it), it has nothing to do with the Legality (code) of installing a 20 amp outlet on a 50 amp circuit.

Building codes can change from one town to the next. If any such rules cover them all, I do not know.

I am not an electrician and that is who you would have to ask for such codes.

I can only say drawing one amp from a ten amp outlet with a  50 amp breaker with 50 amp wiring is safe. I cannot say it meets any building code. 

Such codes change year after year in different areas for whatever reason.

-Don-  Reno, NV

[Crissa]

There's a reason why it's now called the 'uniform building code', Don.

-Crissa

[Richard230]

There's a reason why it's now called the 'uniform building code', Don.

-Crissa

In the city that I worked for every time the latest version of the "Uniform Building Code" was adopted by the city they would tweak it to suit the politics of the time. I can't recall if any changes were made to the electrical code, but the city definitely made changes to the grading and foundation sections of the code (because that was something that I had to enforce) and also to the plumbing section, where plastic pipe would come and go depending upon the local pipe fitter union or home and commercial developer demands. 

[ESokoloff]

I am not an electrician and that is who you would have to ask for such codes.

And the fact that your not an electrician &/or familiar with NEC codes you shouldn’t comment on what’s Expectable (code) in electrical distribution systems.

Codes were enacted for a reason & must be adhered to in-spite of what you or anyone else thinks SHOULD work.

Don’t give advice on what you THINK is Exceptable but rather pass on advice that you KNOW is correct.


Also it’s my understanding that local codes are based on NEC and the requirements generally can be greater but not less then NEC. 

[DonTom]

Don’t give advice on what you THINK is Exceptable but rather pass on advice that you KNOW is correct.

I do KNOW what I said was technically correct.

I do NOT know if it meets code. Two different issues.

-Don-  Reno, NV

[ESokoloff]

Don’t give advice on what you THINK is Exceptable but rather pass on advice that you KNOW is correct.

I do KNOW what I said was technically correct.

I do NOT know if it meets code. Two different issues.

-Don-  Reno, NV

Technically you can breathe under water without any breathing aid (but I do not know if you will survive).
Care to test my theory?

Codes aren’t necessarily written for the probability but rather the possibility.
IE putting a 20a outlet on a 50a circuit will highly probable be Ok.
However the worse case scenario that I can think of is that a component in the device plugged into that 20a outlet starts to go bad & the device draws 45 amps.
The 50a circuit breakers not going to trip & the outlet WILL overheat & potentially start a fire.

I’m just asking that you use discretion when giving advice on power distribution as you wouldn’t want to give advice that could potentially cause any issues

Circuit has a 50 amp breaker on it.  Can I put a plug that is only capable of 20 amps on a circuit that has a 50 amp breaker on it?   I'm sure I won't plug anything in to it that would draw over 20 amps but how about if someone else does?

Of course you can. The 50 amps is the max capacity. If you're under that, you're fine.

Others plugged into the same circuit have a total of 30 amps they can use, if you're drawing 20 amps.

-Don-  Reno, NV

[DonTom]

There's a reason why it's now called the 'uniform building code', Don.

-Crissa

How uniform is it between different states? Not at all! Do a search on those exact words "'uniform building code" and you will quickly see it is not all that uniform between states as well  as different counties in the same state.

-Don-  Reno, NV