From the manual:PRECHARGEThe precharge parameter enables or disables the precharge function. When this parameter is set to “On,” the precharge function does not close the main contactor until the internal power capacitor bank charges to within 10% of the battery voltage. Charging is accomplished internally and an external precharge resistor is not required. If the capacitor voltage does not reach this theshold, a precharge fault is issued and the main contactor is never closed. This reduces inrush current stresses on the capacitor bank and provides protection against allowing full battery power to be engaged if there is a short in the output section. Setting the parameter to “Off” disables the precharge function. The precharge function is required for systems using 48V (or higher) battery packs.
From: sales--- via EV <ev@lists.evdl.org> To: EVDL Post Message <ev@lists.evdl.org> Cc: "sa...@evbitz.uk" <sa...@evbitz.uk> Sent: Thursday, November 29, 2018 8:36 AM Subject: [EVDL] Curtis 1244 Controller Repair Hi, Any Curtis controller experts out there? I may have (rather stupidly - not double checking the pack was isolated before tinkering) damaged my Curtis 1244 controller when I removed a coil-damaged (old unrelated issue) relay powering the DC-DC converter in my 2007 (DC sepex motor) Aixam Mega City Electric car. I think the pack +ve lead that I disconnected from the relay shorted out to ground and now the controller just gives the '3,3' fault code which translates as 'Precharge fault'. After I removed the controller from the car, I tried it in another working car (same make, model and year) and it gave the same fault. I then dissembled it on my bench and found about 250ml of water inside. Now I don’t know if *this* is what caused the pre-charge fault or the shorting but I have subsequently discovered a big 10W or so resistor on the lower PCB which is definitely ’blown’. Unfortunately its markings have been obliterated in failing. I have obtained the Curtis software and, on the bench, powered the controller up with 24VDC and can communicate with the controller using the software apparently normally. I have some reasonable DIY electronics repair skills and pretty good tools and testing equipment and would like to try to fix it, if possible. My remote location (Isle of Colonsay, west coast of Scotland) makes any other method of repair a bit impractical - short of posting the controller away to someone else to fix at, no doubt, vast expense. Curtis won’t help (big surprise). Any thoughts/help would be most appreciated but one possibility has come to light since I got the Curtis software working with the damaged controller… I gather the internal pre-charge circuitry can be turned off in the software. If so, could I simply wire up a relay and ‘suitable’ resistor to the ignition switch so that in the ‘accessories’ position, the ignition switch powers on the relay to pre-charge the controller caps by putting the resistor across the main contactor. Then when the ignition switch is turned to the ‘On’ position (which closes the main contactor etc) the system should start up ‘normally’… Would this work? Regards, EVBitz.uk <http://evbitz.uk/>. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20181128/3b897458/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/20181130/b8625fa7/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)