if I am not mistaken, you need the DP to be 40 A to be certain to draw safely 32 A. So, in your case, you need to lower the A on the EVSE to 32x0.8=25A.

 

You are correct, we have a dp 40 breaker feeding it ,80% of 40 is 32a

 

If the breaker is 40 amps allowable continuous load is 40 A x 0.8 = 32 A, not 25 A

If you didn't read his first message, he said his DP was @ 32A. Nothing about the breaker amperage. Then in his second message wrote about the 40A breaker.

 

If you didn't read his first message, he said his DP was @ 32A. Nothing about the breaker A.

Nope. You need to re-read the original post. He didn't state the DP (double pole) breaker amp rating at all in his first post. But he described #8 AWG wiring which is consistent with 40 A. He confirmed a 40 A breaker in a later post. So the max allowable dip (dual in-line package) setting is 32 A, not 25 A.

 

It really just sounds like a worn out breaker. It would seem that you have fixed the issue. I have had breakers go bad, too. It happens. I don't have too much of a sample size to pull from, but none of the breakers that have failed on me were on particularly heavy loads. I think it's just a matter of time and/or luck.

 

I've had breakers fail after several years of serving EVs. (I've been charging EVs since 1997.)

Fortunately, breakers are (relatively) cheap, and easy for a careful DIYer to replace. It's not for the faint of heart, though. Someone unfamiliar with working in a live e-panel can be killed.

 

It takes some getting used to , we work on live panels all the time at work

 

If you have the space, and the amp surplus, do a 40amp. If you can adjust the charger set it to 29, and you won't trip from starting amps

 

I always thought that you need at least a 40A breaker for a 32A charger? That's what I have. So far (fingers crossed) no tripping problems.

 

On a slightly different topic, I notice the US members also refer to usage in kWh. I thought you (on avg, not the individuals) had sworn off the metric system? Is there a subset of the population that measures ev efficiency in lightning stikes/mile, or light bulb draws as a multiple of fireflies?

Oh no. The letter "K" has been used for many, many years in the US as a symbol for thousand. As in, "I lost $2k at the casino last week." I for one wish the US would fully adopt the metric system.

 

I meant that the Watt is metric, not the 'k'.. but mostly just an excuse to make the lightning bolts/mile joke, as it crossed my mind and made me laugh.

 

On a slightly different topic, I notice the US members also refer to usage in kWh. I thought you (on avg, not the individuals) had sworn off the metric system?

kWh is not metric. Joule is metric. One kWh equals 3.6 megajoules. (The "kilo" is no more metric in watts or watt/hours than it is in nuclear explosion kilotons. )

 

A joule is 1 kg-m^2/sec^2. Not sure why a grouping of metric units (Joule or kWh) would not also be considered metric as they are just scalar multiples. Technically, a Joule is an SI unit.

 

Technically, a Joule is an SI unit.

Yes it is. And a kWh is not an SI unit.

 

I just had the solar PV guys derate the main breaker on my rental's panel from 200A to 175A, because of the addition of 10kW of PV.

I tried to get my solar guys to derate my main 200A breaker, but they insisted in replacing my whole panel with a line side tap for the 13kW PV system. Apparently they had already baked in the cost of doing this on their estimate. As long as it didn't cost me more, I was like okay, whatever. Although they had to patch my wall and luckily I still had matching paint.

 

When my 10 kW of PV was installed, I thought they would backfeed into the panel with a DP breaker. Instead, they connected with "bugs" clamped onto the feeder cable. I even asked the inspector about it (Probably not a great move). But he said it was common.

It helped since it left a couple slots open when I later installed the EVSE.

Mine is the same. Put in back in May 2021. No issues yet.

 

Oh, could be, I definitely am no expert, just went off this. But mostly, I just wanted to be funny.

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I stand corrected. I don't recall any of my schooling talking about whether or not electrical measurements were metric or not. And all my previous research said they were not SI units.

Then I drilled down to an official source, the dot gov Office of Weights and Measures. They list current in amperes among the seven base SI units. Other electrical measurements are derived from it. So, yes, kW and kWh are metric.

And your joke was a good one, btw. In fact, the imperial version of watts would be horsepower. But I like lightning bolts/mile.

 

The British equivalent of a watt is 3.41 BTU/hr.

 

The British equivalent of a watt is 3.41 BTU/hr.

So many equivalents!! Crazy, ain't it? 🤯

By now, @phillipd must be seriously rolling his eyes at our digression. Being an electrician, I'm sure he knew all he needed to know. I had fun exploring this, but I'll stop now.

 

Yeah I know I took it off into the weeds.

Anyway, I'll just close with this note... not even the British still use British Thermal Units since they're on the metric system.

 

Most home circuit breakers operate (trip) as a result of heating a bimetallic strip. With age and loads causing this strip to alternately heat and cool over a period of years, it's unsurprising that eventually the trip point becomes lower.

 

Yeap, HEAT, with summer heat/sun UVs beating on the fuse panel or its surrounding wall; my brand new 50 amp GE breaker will trip on anything more than 32 amp in the middle of hot Texas day. The entire panel box gets hot.

 

we should start a thread with oldtimer computer tech words: "scuzzy," SCSI, or parrallel port LOL, floppy disk,

I like that but I'm not sure it would be OK on a forum devoted to the Chevy Bolt.

 

Yah my first was a tra80 Model I. 16k, cassette, Level 2 BASIC. Later got the Exp i/f rs232 board, lower case kit, and at a Computer Faire picked up 32k more of ram chips and a pair of Teac floppy drives in a case. It ran great, and still did when I got my first MSDOS PC, a DAK package. The Model I is long gone, but the Model 100 is still in a box someplace.