Are you discussing the wiring to the EVSE or the cable to the car? The NEC requires long wire runs to be derated to minimize voltage drop. I suspect that is the reason for #6 wire. Also the new SEAJ1772 standard recommends limiting charging stations to be on 40 amp breakers, providing 32Amps. All of the UL listed connectors have pins and sleeves rated at the full 80 Amps. They have different gage cables that limit the ratings. The 75 amp cables have a big stiff cable and a stiff price. The UL parts I have seen all require the wires be connected at the factory. The Chinese units are a mixed bag of compatibility and quality. David Kerzel Modular EV Power LLC
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Rush Dougherty Sent: Saturday, January 05, 2013 9:54 PM To: 'Electric Vehicle Discussion List' Subject: Re: [EVDL] J1772 for DS 50 EV 1 Station > Because 6 AWG with 90 deg C insulation allows supply up to 75A which > is probably what those public EVSE are designed to support even though > they are connected to 50A breaker and are configured to supply not > more than 30 or 40A (the duty cycle setting of the pilot signal). > > Having a 10 AWG cord allows 40A if the insulation is 90 deg C, > otherwise it is > 30A max, see for example the table at > http://en.wikipedia.org/wiki/American_wire_gauge That table is for one solid wire, not stranded or multiwire conductors. The NEC Table 400.5 (A) and (B) also derate by 20% IIRC, when there are 2 current carrying conductors in the same cable. The J1772 SAE Specs the EVSE cord - "The wiring insulation shall be rated for 105 0C", not 90C. I've got some 105 deg C tables (not NEC) that state that 10 AWG, 2 current carrying conductors, is actually rated at 46.6A. Rush www.TucsonEV.com _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/group/NEDRA)
