feeder taps exploit for ev charging?

E

eliprotiva

Member
Location
Missouri USA
Occupation
EV inovation
hi, im working on democrotizing ev charging, idea is anyone can plug in an evse to charge an ev by default. I want to use the tesla J3400 socket rated for 300 amps air cooled. I want the full 200 amps avalible if user buys such evse or small and cheap 32 amps evse. Plan is to feed total transformer load through signal pins using a ct and basically change ct ratio for transformer kva to keep a standard output for 100% load. I designed a phyical lock that enforces make and break at zero current and touch safe. My question is about NEC code and equipment grounding conductor (EGC). An evse enforces a 20ma max current on PE pin, given i dont have gfci that would mean i have to carry load fault current on PE contact thats rated for 80 amps contentious.
My question is can i use "outside feeder tap" rule (NEC 240.21(B)(5)) to get 200 amps?
https://imgur.com/bmGdnSA
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https://imgur.com/a/nacs
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https://imgur.com/undefined
 
retirede said:
Why do you need 200A capability? The maximum AC charge rate per J1772 (and NACS) is 80A.
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I want to allow many evse to be able to use 1 port. 32 amps is a common rate so thats only 6 vehicles charging. Think state parks, churches etc, we are at 1 ev per 1000 in rural Missouri. The second we get a cheap ev and lots of charging the numbers will go up. Also this plug will be used for the next 50 years and energy is trending towards free so we should expect more consumption. Transforms are already getting bigger
 
As to your question, The outside tap rule would not qualify, at least as drawn on your illustration. Note the conductors must terminate on an OCPD. Why not just put a small panelboard adjacent, with or without a tap rule, and then you could have branch breakers for each outlet?
 
eliprotiva said:
and energy is trending towards free
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The cost are continuing to go up as there is not enough supply to support the load....the being driven by the switch to more equipment being powered by electricity, and even more by the number of data centers being built. It will be decades before we can increase the capacity to match the growing loads.
Sure we can add wind and solar, but without extensive storage that actually acts to drive the costs up. not down.
 
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