On 12/3/20 7:40 PM, Peter VanDerWal via EV wrote:
Any modern house will have 200 Amp service, more than enough to charge TWO evs with Level 2 EVSEs. I've charged an EV at my mom's house and she only has 60 Amp service.
Over the past few years expanding my PV production, I've come to a much better understanding of residential electric service. This is not very relevant to being able to charge EVs on normal residential electric service; I would expect no (or few) problems adding up to 10kw EV charging to a every meter. Especially considering that most charging will be done overnight.
When told they have "200amp service" most folks believe they can pull 200 amps. The limiting factor is likely to be the transformer that services the meter. In rural areas, most meters have a transformer dedicated to each meter. Older meters that were supposed to supply 60 or 100 amp service were likely to have 10kva transformers. That is 10 kw or 40 amps @ 240vac. Long before I started my PV projects, I had my house service upgraded to "200 amps". I had no trouble servicing normal, not "all electric" loads including about 5kw for EV charging. After I started installing PV, I found my inverters would shutdown due to high (~260vac) voltage. My utility replaced my 10kva transformer with a 15kva. I eventually paid them to replace with a 37.5kva. I did not go to 50kva (real 200 amps) due to transformer pole cost. At another meter (with "200 amp service), I was forced to upgrade from 15kva to 50kva to accommodate PV production.
Bottom line: do not assume you can pull (or supply) 200 amps to/from "200 amp service".
Dense development is likely to have several meters sharing a transformer. But transformer limitation is still likely to be a problem if all/most meters attempt to pull full current at the same time.
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