GlennD wrote: jjeff wrote:
GlennD wrote:Most cheap Chinese EVSE's work fine but many (most ?) lack the GFCI coil. That means that they work well but if there is a grounding failure then you are on your own. The J1772 standard is optional and many Chinese EVSE's do not fully comply.
True but when I asked Zencar, the mfg. of this Khons or at least a very close clone, they said they could
add GFCI(possibly for an extra fee??) but most customers(probably with sketchy power sources in Asian countries) didn't want GFCI as they got frequent nuisance trips
From my use of GFI outlets I kind of concur, mine are frequently tripping by such little things as switching a light switch, unplugging another device on the same line, etc. As charging my EV can be critical if I need to get somewhere I'd just as soon eliminate one source of this not happening. I realize GFCI can help with safety but I'm personally willing to forgo a little safety and possibly gain a little more reliability that my car will actually be charged when I want it to be
Of course if you have a hardwired setup and dedicated circuit, nuisance tripping may not really happen but I like to charge out and about and don't always know what else is on the line.[/quote
GFCI is really hard to implement. I have an OpenEVSE that is driving me nuts. To sense a current imbalance requires a very sensitive input amplifier and it can readily see glitches. I am tempted to take the Chinese approach and just eliminate the GFCI circuit entirely but no, it has worked on other units.[Well, I finally found my problem. The EVSE was mounted next to the relay. I replaced it with a contactor and the GFCI problem was consistent. It is much easier th troubleshoot a reproducible problem. It even occurred with the GFCI opamp removed. I finally determined it was magnetic interference from the relay coil. Moving the board totally fixed the problem. With the original relay I never would have found the problem. With the contactor it was always there and easier to troubleshoot. There is no shielding on the OpenEVSE board and the supple problem was hard to find.
Remember the field drops with the square of the distance so moving the board a small distance makes a lot of difference. Every once in a while A problem will drive you to drink! The problem said GFCI but it was not.