> Subject: [EVDL] contactor heats up while charging + BMS analog control?
It clarifies that I need to do something, but not specifically enough for an electronics neophyte like myself. Resistor goes in series to the coil supply (positive or negative?) and capacitor goes across the coil? It sounds kinda like I have to design a simple circuit, I'm not sure that I'm up to it. Are there circuits built for sale at EV suppliers? Thanks for the reply I truly appreciate it If that coil has continuous 14V while you are charging (so that contactor is continuously pulled in for hours while you are charging) then you are attempting to burn up that coil - most coils specified for a certain voltage need an "economizer" (current reducer) when they are engaged for lengthy periods, such as during charging. The simplest economizer is a resistor with a large capacitor across, so the cap causes the full 14V for quick contactor pull-in, then the coil current charges the cap until there is a balance in voltage division between coil resistance and the resistor parallel to the cap. If they are the same, the current as well as the voltage on the coil will be halved and the power dissipated in the contactor will be one quart due to the economizer. Only the resistor will also burn one quart, so you need a power resistor. More fancy designs use a buck regulator or PWM to reduce coil voltage. Hope this clarifies, Cor van de Water Chief Scientist Proxim Wireless Corporation http://www.proxim.com Email: [email protected] Private: http://www.cvandewater.info Skype: cor_van_de_water Tel: +1 408 383 7626 > > > > coil has 14 volts > I realize that the BMS should have control over that contactor and so my > charger negative should go on the other side of the contactor (controller > side rather than battery side) Will that affect the contactor heating? > > Also, nobody responded on the bms control question, I flipped the diode > the other way around and I have no throttle at all. > Thank you > > > > What is the voltage on the negative contactor coil while charging? > > > > Cor van de Water > > Chief Scientist > > Proxim Wireless Corporation http://www.proxim.com > > Email: [email protected] Private: http://www.cvandewater.info > > Skype: cor_van_de_water Tel: +1 408 383 7626 > > > > > > -----Original Message----- > > From: [email protected] [mailto:[email protected]] On > > Behalf Of Mike Malmberg > > Sent: Sunday, June 23, 2013 6:54 PM > > To: evdl > > Subject: [EVDL] contactor heats up while charging + BMS analog control? > > > > I hope the amazing brain trust can help me again. > > I've got my civic running again 144volts of lifepo. I have installed a > > second contactor on the pack negative of battery pack then to shunt to > > contactor then contactor to controller - > > the bms has control over this contactor; the zilla has control over the > > main contactor on the positive side. > > Only while charging does this negative contactor get quite hot. the > > negative of the charger comes in on the pack neg side of the contactor. > > Juice isn't really running through the contactor or is it? It should be > > flowing to the battery away from the contactor. the charge wire > > connected > > to the contactor isn't particularly warm but the body of the contactor > > is > > hot. what is up? charger runs at 30 amps contactor is Tyco Kilovac > > 500A > > 320VDC LEV200 > > > > 2nd question > > I am having a little trouble trouble shooting why the Orion BMS is not > > limiting current. They gave me steps to check on but could I trouble > > you > > guys for the explanation of what the zilla hairball does with the > > throttle > > pot input? Is that 0 to 5k pot controlling voltage in the hairball? > > As > > you step on the pedal the resistance increases and reduces voltage to > > signal more juice? I would really like to understand what is happening, > > as > > it makes it easier to troubleshoot. The Orion BMS has an analog > > discharge > > current limit signal that is 0 - 5 volts connecting that through a > > diode > > to one side of the pot was the recommended way to hook it up. This is > > where my brain fuzzes over. I may just have my diode in backwards but > > I > > was hoping to get an explanation of how this all works. > > Thanks so much > > > > 92 civic HB 144v Calb 180 SE, Zilla 1k LV, Orion BMS, Elcon 5k > > charger, > > 70 mile range to 80% > > > > Thanks > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130625/381ffd41/attachment.htm > > > > > ------------------------------ > > > ------------------------------ > > > > - > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20130626/24816158/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)
