True. I actually meant I've only seen 20A outlets in commercial installations. My house is wired with 20A circuits and 15A outlets.
On October 20, 2015 10:36:44 PM MDT, EVDL Administrator via EV <ev@lists.evdl.org> wrote: >On 20 Oct 2015 at 19:34, Mike Nickerson via EV wrote: > >> I've seen 20A circuits, but only in commercial installations. > >You'll see plenty of 20a branch circuits in homes - all newer homes are > >wired this way - but 20a receptacles on them are indeed pretty rare. > >This is because the code has an exception allowing cheaper 15a-rated >receptacles on a 20a branch circuit, as long as there's more than one >outlet >on the circuit. If there's only one receptacle on the circuit, it must >be a >20a-rated recept. (Code experts argue over whether a duplex receptacle > >counts as one or two outlets.) > >IIRC, the code ALLOWS but doesn't REQUIRE 20a-rated receptacles on a >multiple-receptacle 20a branch circuit. I installed 120v 20a recepts >on the >branch circuit in my garage to allow for better EV charging, though I'm >not >100% convinced that (once you're beyond the 50 cent bargain bin junk >receptacles) there's much difference between the guts of a 15a-rated >recept >and those of a 20-a rated recept. > >One more note about this. Because code limits sustained load on a >branch >circuit to 80% of its maximum, you can charge at no more than 1920 >Watts >from a 120v 20a residential branch circuit. If your EV gets 250 Wh/mi >and >has a typical 80% charging efficiency, you gain just over 6 miles of >range >per hour of charging. If you sleep 8 hours and charge while you sleep, > >that's 48 miles you can drive per day. > >It could be more than that, since some switchmode chargers do better >than >80% efficiency. Also, staying below 80% SOC increases battery charging > >efficiency. But that's a pretty good rule of thumb. > >You're much better off going with a 240v circuit and charger. A 240v >20a >circuit gives you 3840 Watts, for over 12 miles of range per hour of >charging - 96 miles overnight. > >A 50a range / welder circuit is an even better bet, as long as your >charger >has the guts to use it. That recept allows 9.6kW charging. At that >rate >the EV described above gains over 30 miles of range for each hour of >charging - about 245 miles overnight. > >David Roden - Akron, Ohio, USA >EVDL Administrator > >= = = = = = = = = = = = = = = = = = = = = = = = = = = = = >EVDL Information: http://www.evdl.org/help/ >= = = = = = = = = = = = = = = = = = = = = = = = = = = = = >Note: mail sent to "evpost" and "etpost" addresses will not >reach me. To send a private message, please obtain my >email address from the webpage http://www.evdl.org/help/ . >= = = = = = = = = = = = = = = = = = = = = = = = = = = = = > > >_______________________________________________ >UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >http://lists.evdl.org/listinfo.cgi/ev-evdl.org >Read EVAngel's EV News at http://evdl.org/evln/ >Please discuss EV drag racing at NEDRA >(http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
