I hadn't planned on test driving the car today. However, this morning after I hooked up the Link-10 meter and finished all of the testing I wanted to do, I had some extra time and enthusiasm before work. So I thought "What the hell".
The first clue that something might go wrong was when I tried to pre-charge the capacitors in the motor controller. This is done by connecting a resistor of some kind across the contactor to let a limited amount of current slowly charge the capacitors - as opposed to sending a large inrush of current at them by stepping on the throttle. Many people use a standard light bulb for this, which is what I used today. However it did not work as planned. The light bulb is supposed to light and slowly go out as the charge current decreases. My light bulb stayed lit. Hmmm.
I have been very cautious with this project and I continued that approach today. For the first test of the motor, controller and drive train at 160 volts I jacked the rear wheels off the ground. I went ahead and switched on the main contactor, energizing the controller. I lightly stepped on the accelerator pedal and everything worked as expected. Exciting!
Well, there was nothing left to do at that point but take it for a drive. I pulled the jack out of the way, jumped in and put her in reverse. The throttle was a little touchy - as I had been told to expect. It took very little pressure on the pedal to get the car moving. I got the feel of it right away as I backed into the street. I put the 3-speed manual transmission into second gear and pulled slowly forward. Everything was very smooth. It felt just like driving the Duster as before. I drove slowly about 50 yards to the neighbors house, pulled into their driveway and turned around. I again put it into second gear and drove back to my house. At that point, I shut everything down and proceeded to check everything. I used my infrared thermometer to check for anything abnormally hot. All appeared fine.
I then took a short break and contemplated parking the car so I could get ready for work. But the lure of a more rigorous test drive got to me. So OK, one more drive and then I'll park it for the day. I backed out of the driveway and headed down the street. I accelerated more on this drive, smoothly hitting 26 MPH before letting off. I coasted to a stop in another neighbor's driveway a few houses down the street.
At this point came another clue that all was not well. A strange noise emanated from under the hood. The best I can describe it is that it sounded like cards dragging against a bicycle spoke. I went ahead and backed out of the driveway and headed back toward my house. I stepped on the pedal but there was noticeably less acceleration than before. My first thought was that the batteries had run too low - although they had a 70% charge when I began this excursion. I stepped a little further on the accelerator pedal - still sluggish. Then I pushed down a little further and BANG! I felt something hit the firewall or the underside of the car, and heard something hit the pavement as the car slowed to a stop.
I immediately thought that it was a mechanical failure. In fact, I thought my motor-to-transmission coupling had broken. I got out and walked back to see what had fallen off of the car. All that was in the street was a 2 inch by 3 inch piece of thick green plastic. Hmmm. I have been over every inch of this car and I have never seen anything like that on it. I almost tossed it, but decided to hang onto it just in case.
When I walked back to the car I detected the distinctive smell of an electrically burned (or burning) device. Again, hmmmm.
I popped the hood to take a look, prepared to do battle with flames. (BTW, I had taken my fire extinguisher with me). I didn't have to look too hard to find that the end of the motor controller case - the end facing the firewall - had blown completely out. Interestingly, the fragments of the end piece that were remaining in the car were a thick green plastic material. So that mystery was solved. I am guessing that the cards-against-spokes sound was high-amperage arcing inside the controller before it blew up.
In a way, I was relieved to find that it was a component failure instead of something that I had installed incorrectly or wired wrong. That sense of relief quickly faded however.Earlier this week I had tried to examine the tiny adjustment screws inside the controller case - just for future reference. I wasn't able to see any adjustment screws so I gave Steve Clunn from Grassroots EV a call, as I had purchased my motor and controller from them. (BTW, Steve and his partner Jon Hallquist have always been very accessible and helpful.) During that conversation Steve told me that they had been experiencing a very high failure rate with these Logisystems controllers. In fact, it had been so extensive that Grassroots had stopped selling Logisystems.
Upon speaking with both Steve and Jon after my controller failure today, I found out the true extent of the problem with Logisystems. Logisystems are in a mess. No new controllers are being shipped out. Many of the ones they previously shipped have blown up. They produced an upgraded controller that had a higher failure rate than the one it replaced. Failed controllers are not being fixed and sent back. Logisystems has apparently been full of promises but has not delivered on any. At least one customer has filed suit against them.
This isn't good. The reason I purchased the Logisystems in the first place was that they were the only controller in this price range advertising a unit good for 156 volts. With my heavy conversion I wanted to stay with 156 volts. Now I have the distinct feeling that I will never see a repaired controller if I send this one back to Logisystems. Grassroots will not/cannot refund my $1345.00. I am currently sorting out my options.
The one positive thing about today is that I now know I have an electric vehicle ready to roll if I can come up with a motor controller.
