I always built my conversions with a solenoid connecting power from the controller to the motor and the throttle controlling the solenoid. When the throttle was off the power was off. If you reversed with your foot in the throttle, then you deserved what you get. Where is common sense and safety?
--- On Thu, 4/11/13, Michael A. Radtke <[email protected]> wrote: From: Michael A. Radtke <[email protected]> Subject: Re: [EVDL] Reversing Contactors Yet Again To: "Electric Vehicle Discussion List" <[email protected]> Date: Thursday, April 11, 2013, 3:32 PM Jeff and Lee, Thanks for your responses. > 50/50 forward/reverse duty That seems reasonable. So there really is no issue with rewiring. > beware of reduced holding current I checked it out and once the solenoid bottoms out, the reduced current keeps it very solid. If the van hits a bump hard enough to dislodge it, I'll have a few broken bones as well. > both coils energized. I've never seen it done and it might > be hairy In this case it is quite straight forward. Just replace a || with an X. Spacers will avoid the obvious short. > There is only a spring holding it closed, and it has to > be weaker than the coil's force Not so on this contactor. The actuator is a solenoid. However, the contacts are isolated from the actuator by springs. So, at either end of the actuator's throw, the isolation springs are compressed the same amount ensuring that the contact pressure is the same in either position. So, at least in the case of this contactor there should be no difference in current carrying capacity. > can get ruinously high currents if it shorts the armature > while the vehicle is moving I didn't think of that. I guess that's because of the residual magnetism in the field. That armature sees an alternating current so has less residual magnetism and thus generates a much smaller AC current in a shorted field on coasting. The paired contactors could have a shorting overlap while switching. My old home made switch could not. Perhaps I should re-consider rebuilding my old switch. Thanks for your advice, Mike _______________________________________________ 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) -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130411/aea35ec4/attachment.htm> _______________________________________________ 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)
