Charging On 6-50

[AlanSubie4Life]

replace the breaker with a 40A breaker, use the Duosida on it with the adapters,

And yes, FWIW, I wouldn't recommend this, though I did mention it as a possibility, since it's now 40A with a 20A device connected. It's not something personally I would do, either.

I ran Nema 14-50 outlet 50A circuits for a while with 20A breakers with my Chevy Spark EVs since they only charge at 3kW. Having a breaker that would blow at 20A gave me some very slight additional peace of mind (I would have run 15A if I had been able to find that quad type in stock). I had modified the EVSE that came with the car to run at 240V rather than 120V, too...so I wanted extra protection - though the mod was very safe as far as I was concerned; I had put a new plug on the EVSE instead of the 120V plug, I had added a 14-50 plug, and rewired the connections internal to the EVSE to allow 240V onto the J-1772. I got the idea from a YouTube video - it must have been safe!

I'm just recommending what I would do. If I don't need the high current breaker, I lower the value to what I need. Breakers are not that expensive, it's ok to have a couple extra floating around.

 

[Rocky_H]

So I am a little out of my comfort zone here since I have not researched deeply this exact topic, but I was just calling out that I am not sure it is a great idea to be using a 16a EVSE on a 30a circuit.

Yes, you are right, we use very low amperage appliances on outlets capable of a lot more amps, but the key here is that the appliance is designed with knowledge about the amperage of the circuit in mind.

I'm surprised you would even wonder about that. There are lots of EVSEs that are built to use small amps but plug into higher amp circuits. People here know that Clipper Creek is the top of the line go-to builder of reliable high quality J1772 EVSEs. About half of their plug-in low amp units are built for bigger sized circuits.

Here's a 16A one for a 6-50:
16A Level 2 EVSE LCS-20P with NEMA 6-50 | ClipperCreek

Here's a 16A one for a 14-30:
16A Level 2 EVSE LCS-20P with NEMA 14-30 | ClipperCreek

Here's a 16A one for a 14-50:
16A Level 2 EVSE LCS-20P with NEMA 14-50 | ClipperCreek

And yes, the specifications tabs do say to go ahead have those outlets as full 50A circuits for the 6-50 and 14-50 and 30A circuits for the 14-30. So this is totally proper and common. An appliance is expected to protect itself, but the circuit breaker is expected to protect the wire and outlet. All of this lines up just fine with a low power appliance in a higher power outlet/circuit.

 

[eprosenx]

I'm surprised you would even wonder about that. There are lots of EVSEs that are built to use small amps but plug into higher amp circuits. People here know that Clipper Creek is the top of the line go-to builder of reliable high quality J1772 EVSEs. About half of their plug-in low amp units are built for bigger sized circuits.

Here's a 16A one for a 6-50:
16A Level 2 EVSE LCS-20P with NEMA 6-50 | ClipperCreek

Here's a 16A one for a 14-30:
16A Level 2 EVSE LCS-20P with NEMA 14-30 | ClipperCreek

Here's a 16A one for a 14-50:
16A Level 2 EVSE LCS-20P with NEMA 14-50 | ClipperCreek

And yes, the specifications tabs do say to go ahead have those outlets as full 50A circuits for the 6-50 and 14-50 and 30A circuits for the 14-30. So this is totally proper and common. An appliance is expected to protect itself, but the circuit breaker is expected to protect the wire and outlet. All of this lines up just fine with a low power appliance in a higher power outlet/circuit.

Yeah, those totally exist but the key difference being that they were built for those larger circuits in mind. If clipper creek puts a 6-50 plug on the EVSE then it builds and tests the EVSE under the assumption that it is connected to a 50a circuit. The Duosida EVSE has a 6-20 plug on it and so their design criteria was that it would be plugged into up to a 20a circuit.

I may be wrong on this, but I am pretty sure this would run afoul of UL ratings. I wish I had specific UL standards to reference here or a subject matter expert we could bring in.

 

[Rocky_H]

Yeah, those totally exist but the key difference being that they were built for those larger circuits in mind. If clipper creek puts a 6-50 plug on the EVSE then it builds and tests the EVSE under the assumption that it is connected to a 50a circuit. The Duosida EVSE has a 6-20 plug on it and so their design criteria was that it would be plugged into up to a 20a circuit.

Huh? The way you're describing this sounds very odd--like not how electric circuits work. You're making it sound like the circuit forces an amount of current into the device, and the larger the circuit rating the more current it forces in, like it could overload a smaller rated appliance. That's not how that works at all.

It connects onto the circuit, and it has access to the voltage on those two pins. It will draw however much current it is made to draw. It will not behave differently whether it's a 20A or 50A or 150A circuit. The circuit isn't forcing more than the 16A the EVSE is trying to pass through.

I may be wrong on this, but I am pretty sure this would run afoul of UL ratings. I wish I had specific UL standards to reference here or a subject matter expert we could bring in.

And I guess you maybe didn't notice that all of those Clipper Creek units that are 16A on 30 or 50 amp outlets are all UL certified.

 

[eprosenx]

Huh? The way you're describing this sounds very odd--like not how electric circuits work. You're making it sound like the circuit forces an amount of current into the device, and the larger the circuit rating the more current it forces in, like it could overload a smaller rated appliance. That's not how that works at all.

It connects onto the circuit, and it has access to the voltage on those two pins. It will draw however much current it is made to draw. It will not behave differently whether it's a 20A or 50A or 150A circuit. The circuit isn't forcing more than the 16A the EVSE is trying to pass through.

And I guess you maybe didn't notice that all of those Clipper Creek units that are 16A on 30 or 50 amp outlets are all UL certified.

So specifically what I am talking about here is what happens if the cord from the plug on the EVSE to the EVSE itself got sliced and there was a short, say hot to ground. You need the wire gauge of that cable to be sufficient to flow enough fault current such that the circuit breaker opens (rather than just sitting there melting the cord). If that circuit breaker is a 50a breaker vs. a 20a breaker that presumably would take a different amount of fault current.

My thesis is that the Clipper Creek EVSE unit that has a 6-50 plug on it has a thicker gauge cord up to the EVSE than the one with a 6-20 on it (even though both may only be rated to deliver 16a to the car).

Another example would be say using an adapter that goes from NEMA 5-15r to 14-50p with no overcurrent protection in it. So that would let you plug in random 5-15 extension cords and devices to a 50a circuit. That would be really dangerous especially if you used a power strip or splitter... The expectation is that when you have a NEMA 5-15 as a receptacle type that it is either on a 15a or a 20a breaker (the 15 or 20a thing is a weird US thing). If you have a 6-20 receptacle the expectation is that it is protected by a 20a breaker.

 

[Rocky_H]

So specifically what I am talking about here is what happens if the cord from the plug on the EVSE to the EVSE itself got sliced and there was a short, say hot to ground. You need the wire gauge of that cable to be sufficient to flow enough fault current such that the circuit breaker opens (rather than just sitting there melting the cord). If that circuit breaker is a 50a breaker vs. a 20a breaker that presumably would take a different amount of fault current.

I see where you're going with that part, but that is generally why vacuum cleaners or microwaves or hair dryers or just about anything has a simple fuse in it. That is what is there to protect that stuff that is outside of the wall.

My thesis is that the Clipper Creek EVSE unit that has a 6-50 plug on it has a thicker gauge cord up to the EVSE than the one with a 6-20 on it (even though both may only be rated to deliver 16a to the car).

And yet that doesn't really seem to be the case with a lot of 240V kinds of appliances that are like this. When Tesla went to the 2nd generation UMC, it has a thinner power cord that plugs into the wall that is more appropriate for the 32A draw, but it is still intended to be plugged into outlets that are oversized from that on 50A circuits. And you can find this on other things too, like air compressors. I'm looking in the install guide for a Husky brand 240V air compressor right now, and it lists "minimum branch circuit requirement" of 20A. So it seems to allow a bigger circuit.

Another example would be say using an adapter that goes from NEMA 5-15r to 14-50p with no overcurrent protection in it. So that would let you plug in random 5-15 extension cords and devices to a 50a circuit. That would be really dangerous especially if you used a power strip or splitter... The expectation is that when you have a NEMA 5-15 as a receptacle type that it is either on a 15a or a 20a breaker (the 15 or 20a thing is a weird US thing). If you have a 6-20 receptacle the expectation is that it is protected by a 20a breaker.

Yeah, and I think that is handled mostly by appropriate building codes. They specify the types of circuits and receptacles that can be in houses like that. 120V convenience outlets are 15 or 20A. The 240V circuits have different kinds of location requirements, etc. and there aren't really splitters and power strips that are commonly used for 240V plug types in residential settings.

 

[Gyrobob]

Good news. You should be able to change to a 40a circuit breaker, then use the 6-50 adapter directly. I've used that exact setup (8awg wire, 40a circuit breaker) to charge my cars for years.

To answer the question that no one else did, yes your plan with the 16a Duosida would work just fine, BTW.

I have a few 6-50 welder outlets in the workshop on 50 amp circuit breakers wired with 6AWG 2-conductor (with ground) cable. I also have an expensive, thick, welder extension cord I bought decades ago. I'm thinking I could just use a 6-50 adapter for the Tesla mobile connector with those pieces. With the way we use the MYP, charging from the 110v socket we use now, even with the 4mph charging rate, works fine,... but I can see the occasional need to charge at a higher rate if all of a sudden we need to take a trip and the battery is low. The one disadvantage to using the welder hook-ups is the big fat extension cord cable on the floor of the workshop and garage, but it would be temporary.