Paul, I will ask around about this. I had a similar problem (not JuiceBox related) where my US Electricar S10 had internal GFCI detection on the incoming AC line. It usually worked on 110V and it probably also should work on a residential 240V which is 2 balanced 120V legs, but the place where I wanted to charge at 240V had only commercial 480V 3-phase available anywhere near the parking lot. So, I took one leg of that (277V) which was powering the light in the parking lot on a timer, and I attached a step-down transformer which was an industrial dry type transformer that used to have 240V primary and about 36V secondary. I put the two in series and connected that to the 277V, giving me a 36V step down (auto-transformer) to 240V. Since the transformer only sees the difference between input and output and the truck never draws more than approx. 3kW (13A typically) the transformer never saw more than ½ kVA.
However, what I discovered was that on this single phase 240V power, the truck’s GFCI would always trigger, while on 110v it would only occasionally pop. So, I disabled the built-in GFCI. Why can toasters and RVs be plugged in without GFCI and our super-protected EVs struggle with hair-trigger GFCI that disables charging at inconvenient times? Anyway, while disabling the GFCI may not be your preferred solution and I will try to find out what can be done – it would be my own preferred solution… BTW, I did charge Lawrence’s 2016 Leaf with 30kWh battery on my JuiceBox without trouble. I had forgotten to adjust the pilot, so it pulled full power (32A = 7.7kW) for over an hour on my NEMA 14-30 circuit – indeed slightly overloading the 10 gauge wiring, but it survived. As far as I know, the GFCI is original in my JuiceBox. Cor. Sent from Mail for Windows 10 From: Paul Wallace via EV Sent: Friday, June 15, 2018 1:40 PM To: ev@lists.evdl.org Cc: Paul Wallace Subject: Re: [EVDL] Juicebox Cor, finally, someone with some background with the Juicebox Classic silver case unit. I've got a Juicebox classic 40A on a 50amp outlet which should put out enough power for my PFC40 charger. It works fine with both the 2017 Volt and the 2015 Spark, but they can only manage around 3.3kw. The problem comes when I plug in my S10 with the PFC40. If I turn up the charger power past about 4kw or so, the Juicebox works for a while, 10 to 15 minutes, but then faults with a GFCI error. I managed to find an old build document online for the kit which explains how to monitor the serial stream and also put a volt meter on the GFCI sense pin to the microcontroller and watch the offset voltage. I think that the Juicebox is a factory version as the GFCI transformer has a glob of white RTV fixing the 240VAC input wires in what should be the best position for minimizing the offset voltage. Everything starts out relatively good. The offset voltage is in the 50mv range as I remember. After about 5 minutes , the offset begins to increase while charging current remains steady. Once the offset voltage gets up to around 200mv, the fault occurs. Is there anything I can do to improve the offset voltage so this doesn't happen? I'd like to be able to use the full power of the Juicebox since the PFC40 will handle it. thanks, Paul Wallace -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180615/9b7bf814/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20180615/b9b6256d/attachment.html> _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
