Burned out wall receptacle and plug. ugh (JuiceBox 40)

i8iridium

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True, but I guess my area doesn’t require it. I Live about 25 miles north of NYC. Seems to make sense to have it but it is what it is.
Yup, it’s weird even some counties in the same state will adopt only certain parts of the code, or haven’t started using 2020 code. Or depends on the mood the inspector is in. Lol
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AKgrampy

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I am not going to argue between 40 amp and 32 amp. I will say that losses are 60% higher at 40 amps than 32 amps. I am actually glad I read this thread because I never really took that into consideration. 32 amps will work for me as a charging speed and I am going to drop my EVSE from 40 to 32 amps. Of course that 60% power loss increase would also result in heat so any flaw in the connection that increases resistance would result in increased heat. Enough to cause damage - I do not know. I am also fine in not finding out.
 

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I am not going to argue between 40 amp and 32 amp. I will say that losses are 60% higher at 40 amps than 32 amps. I am actually glad I read this thread because I never really took that into consideration. 32 amps will work for me as a charging speed and I am going to drop my EVSE from 40 to 32 amps. Of course that 60% power loss increase would also result in heat so any flaw in the connection that increases resistance would result in increased heat. Enough to cause damage - I do not know. I am also fine in not finding out.
Now this is something I'd consider dropping down for...do you have the source that validates/explains this loss?
 

Scooby24

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I have the Juice Box 40. My electrician initially installed a commercial grade outlet. But, after reading the forum and and having a better understanding regarding these outlet, I too upgraded to an Industrial grade outlet. I appreciate everyone's input and advice on this topic. And, an extra $10 spent on a high grade outlet, for peace of mind... no brainer for me.

Industrial grade outlet.png
For what it's worth, this is what's sold in Lowe's/Home Depot and is not the true industrial spec....it was discussed on an older thread that's there's no code specification to differential true industrial grade from commercial grade and you can't trust the manufacturer's description as such.

This legrand 14-50 is what I had prior to upgrading to the Cooper/Eaton 5754N.

I haven't yet seen anyone with the P&S/Legrand have a failure, but it's not to the same standards as the big boys.

Eaton left, Pass & Seymour right. All the ones we're talking about in this thread are 2.4" vs. 2.2"

Ford Mustang Mach-E Burned out wall receptacle and plug. ugh (JuiceBox 40) 1661378172326
 


Mach Tuch

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I installed a Hubbell 14-50 and I have Bryant (made by Hubbell) sitting on a shelf. The contacts inside each plug slot are full size and what I believe to be the most import part is how the wires are clamped on the back. The romex stranded wire gets squeezed together, so it acts more like solid wire with excellent contact. The lesser outlets connect to the wire with a screw screwing down into the wire, actually causing some separation, and as a result less contact. I will show a photo of the Bryant in a few minutes.
 

i8iridium

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I am not going to argue between 40 amp and 32 amp. I will say that losses are 60% higher at 40 amps than 32 amps. I am actually glad I read this thread because I never really took that into consideration. 32 amps will work for me as a charging speed and I am going to drop my EVSE from 40 to 32 amps. Of course that 60% power loss increase would also result in heat so any flaw in the connection that increases resistance would result in increased heat. Enough to cause damage - I do not know. I am also fine in not finding out.
Bad at math, someone else can figure out the losses...lol

I've logged charging at the following:

235.36VAC 30A (7060.8 watts), the battery charger output is 372.65VDC 18.7A (6968.6 watts) - 92.2 watt difference between AC and DC
237.71VAC 24A (5705 watts), the charger output is 372.05VDC 14.1A (5245.9 watts) - 459.1 watt difference between AC and DC

Both are at about 85% SOC.
 
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Maquis

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Bad at math, someone else can figure out the losses...lol

I've logged charging at the following:

237.71VAC 30A (7131.3 watts), the battery charger output is 371.38VDC 18.7A (6944.8 watts) - 186.5 watt difference between AC and DC
240.89VAC 24A (5781.36 watts), the charger output is 372.05VDC 14.1A (5245.9 watts) - 535.5 watt difference between AC and DC

Both are at about 85% SOC.
You can’t really calculate the efficiency unless you know the power factor on the AC side. On the AC side, V x A = VA (Volt-Amperes, not watts. VA x pf = watts.
I don’t know what the power factor of a typical EV Charger is, but it can’t be ignored.
In your example, the losses are greater at the lower charge rate. And that invalidates the 60% figure from the post you quoted!
 

i8iridium

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You can’t really calculate the efficiency unless you know the power factor on the AC side. On the AC side, V x A = VA (Volt-Amperes, not watts. VA x pf = watts.
I don’t know what the power factor of a typical EV Charger is, but it can’t be ignored.
In your example, the losses are greater at the lower charge rate. And that invalidates the 60% figure from the post you quoted!
Dang, good point, so i was effectively calculating a power factor of 1.
 

i8iridium

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You can’t really calculate the efficiency unless you know the power factor on the AC side. On the AC side, V x A = VA (Volt-Amperes, not watts. VA x pf = watts.
I don’t know what the power factor of a typical EV Charger is, but it can’t be ignored.
In your example, the losses are greater at the lower charge rate. And that invalidates the 60% figure from the post you quoted!
I transposed some numbers in my post, which I fixed. Still missing pf, though. But below is where I got my numbers from, so I wonder if maybe it's showing the adjusted wattage?

Ford Mustang Mach-E Burned out wall receptacle and plug. ugh (JuiceBox 40) 1661383283101
Ford Mustang Mach-E Burned out wall receptacle and plug. ugh (JuiceBox 40) 1661383302445


I'm not sure BAT_CHARG_PWR is on the AC or DC side. My head hurts honestly. lol
 

devmach-e

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Bad at math, someone else can figure out the losses...lol

I've logged charging at the following:

235.36VAC 30A (7060.8 watts), the battery charger output is 372.65VDC 18.7A (6968.6 watts) - 92.2 watt difference between AC and DC
237.71VAC 24A (5705 watts), the charger output is 372.05VDC 14.1A (5245.9 watts) - 459.1 watt difference between AC and DC

Both are at about 85% SOC.
Something to keep in mind is that a certain amount of power from the wall is diverted from charging to instead run vehicle systems like battery cooling when charging. So less power is available for charging when using an EVSE that is only 24A versus 30A.
 

AKgrampy

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Now this is something I'd consider dropping down for...do you have the source that validates/explains this loss?
Loss is simply current squared times resistance. So at 40 amps it is 1600 amps squared and at 32 amps it is 1008 amps squared for a 60% difference. I do not know the total resistance involved so I can’t say what the total losses would be. To be totally fair you would also have to factor in that it takes longer to charge at 32 amps so losses occur for a greater period of time. So I just did some quick math and used a 4 hour charge at 40 amps would take 5 hours at 32 amps. So 6400 amps squared for 40 amps and 5040 amps squared for 32 amps. I doubt in the grand scheme of things it amounts to that much but I guess savings is savings. Of course time is money too and I would only take this approach at home. If I ever DCFC I want charging done as fast as possible to get back on the road!
 

AKgrampy

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I transposed some numbers in my post, which I fixed. Still missing pf, though. But below is where I got my numbers from, so I wonder if maybe it's showing the adjusted wattage?

1661383283101.png
1661383302445.png


I'm not sure BAT_CHARG_PWR is on the AC or DC side. My head hurts honestly. lol
And my guess is it is not that much so no need for a headache!
 

i8iridium

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Something to keep in mind is that a certain amount of power from the wall is diverted from charging to instead run vehicle systems like battery cooling when charging. So less power is available for charging when using an EVSE that is only 24A versus 30A.
fair point. There’s too many variables to loose sleep over. I’ll charge at 48A and be happy.
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