I'm going to install a ChargePoint Home Flex-NEMA 14-50, SKU: CPH50-NEMA14-50-L23. Already have the outlet installed and ready to go, so just doing the charger now. I'm a little confused by the below chart regarding how many amps to set the amps/app for. Is it the circuit rating or the max load? It advertises 37 mph, but it seems like I'm supposed to set it for 50 A circuit rating. Thanks in advance for any advice!
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Erik Fernandez
The answer is mostly entirely dependent on what gauge wire you installed. There are some other factors such as what breaker you installed, plug vs. hardwire, what hardware you've got on hand, what the capacity of your home's electrical service is, limitations of the ID.4 onboard charger, etc.
But let's start at square one: what type of wire did you use?
(...and to cut to the quick if you installed 6 awg copper and a 50 amp breaker you'll set the EVSE to 40 amps, which would be the 80% continuous load value of a 50A circuit's rating.)
But let's start at square one: what type of wire did you use?
(...and to cut to the quick if you installed 6 awg copper and a 50 amp breaker you'll set the EVSE to 40 amps, which would be the 80% continuous load value of a 50A circuit's rating.)
If you Google it, you're apt to get an incorrect answer like this:
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"A 20 amp circuit breaker can handle 16 amps, or 1920 watts, at 80% of its rating. This is because thermal magnetic circuit breakers are designed to trip at 80% of their rating. "
The 80% rule applies to "continuous electrical loads" which the NEC defines as lasting 3 hours or more.A 50 amp circuit is perfectly fit to handle 50 amps of draw, and this is below the circuit's built in safety factor. A 50 amp breaker may trip at 50 amps, or maybe 53, or maybe 49 but hopefully not.
The 80% rule is just an additional precautionary measure that's built into the electrical code.
100% agree, a qualified electrician ought to know best, but based on the opening post it sounded like a DIY job...
That's interesting that Chargepoint has the owner set for the circuit rating, not the
I suppose even my "dumb" Clipper Creek follows this convention: the 40A EVSE has "50" in the model number.
The trouble with resistance testing is that 6 AWG wire loses only 0.04 Ω over 100 feet, which is impractical to measure with a consumer-grade multimeter in the field.
There's an electricians' trick to estimate the amount of Romex remaining on a spool using this same method, but for new, gauge 14 copper with no splices and at 2.5Ω over 1,000 ft., the technique is a bit more practical.
I'm not sure how an EVSE would be expected to accomplish this type of wiring diagnosis, especially since most EVSEs don't connect to the neutral. They are required to check for ground so nobody is electrocuted if there's stray voltage, but I'd guess the unit couldn't detect the difference between proper ground or neutral being used (incorrectly) for this purpose.
There's an electricians' trick to estimate the amount of Romex remaining on a spool using this same method, but for new, gauge 14 copper with no splices and at 2.5Ω over 1,000 ft., the technique is a bit more practical.
I'm not sure how an EVSE would be expected to accomplish this type of wiring diagnosis, especially since most EVSEs don't connect to the neutral. They are required to check for ground so nobody is electrocuted if there's stray voltage, but I'd guess the unit couldn't detect the difference between proper ground or neutral being used (incorrectly) for this purpose.
Re: receptacles vs. hardwire, this all goes back to the NEC as the source. I'll put the applicable sections in quotes because it's a long list, so click to expand. The very last one is the one that matters most.
2020 Nat'l Elec. Code said:
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