Rinehart Inverter Failure
This inverter has been very much a problem from the beginning. Mechanically it was very easy to install, to get it mounted on the same mount as the Scott Drive, connected to coolant and connected to all the low and high voltage lines without any issues. But electrically and programmatically it has been problematic. First, I had to create a completely new wiring harness because the Rinehart uses Ampseal connectors and the inverter I replaced used Epic. The motor encoder control signals were also on an Ampseal connector so I had to build interface to the encoder cable that has Sealcon M23 round connectors. Even the cross-over box that I used to break out the wires had to be significantly changed and new wires had to be run for more control. I found that the inverter requires a very specific set of conditions of connections and firmware settings to be met so that it will enable the output. What makes the Rinehart great is that I had access to every firmware value that affects the opertion of the car. But that is also what makes it difficult. Even after working over the past month all the conditions still were not satisfied to enable torque output. The inverter shows that is enabled and in Run mode, but nothing happens when the accelerator is pressed. I have been getting support from Cascadia Motion and working through the issues. They discovered reviewing the output from the firmware listing is that the Hardware (HW) version had changed. That is not possible outside the factory so some transient in the system corrupted the EEPROM memory. They thought that updating the firmware may fix the inverter issues. Updating firmware in an inverter is not a new thing for me, I had to do that on both the Scott Drive and DMOC. For the Rinehart it just required the serial interface and the connection to the Software upload enable pin. I was preparing to do the firmware update, I had gotten all the connections I needed, but when I turned the car off to make the connections, I hear a loud bang and I could see the Rinehart visibly shake (I could feel it in the car too). There are no mechanical switches in the Rinehart so that noise could only be a large electrical discharge inside the unit. I tried to turn the car on, but the main contactors would not close. Those are now controlled by the Rinehart. I discovered that the 12V 5-amp fuse to the Rinehart was blown. I replaced the fuse, but when I turned the car on it blew it again. I measured the input impedance for the 12V into the Rinehart and it is several mega ohms so this is a semiconductor short – when the circuit is energized it draws too much current. I checked with the support from Cascadia Motion and they said a 10-amp fuse would be okay, but I found after a few minutes the inverter would blow that one too. It was after the 10-amp fuse blew that I could smell the familiar smell of burnt electronics. So now the Rinehart is probably bricked. Cascadia Motion does have an RMA and repair service. They charge $650 to evaluate the unit and give you a quote for repair. The problem will be what actually failed. Was it just the controller board or did one or more of the IGBT transistors blow too? Something had a large electrical breakdown to make the unit move and create that loud bang. I requested and received an RMA, but I will have to think about if I even want to know what went wrong. If it is something major the repair could be as much as a new unit. That unit won’t even turn on with is not promising and the $650 could be just a waste of money. I removed the inverter from the car, it had to be cleaned of cooling fluid and the inlets capped, in case I decide to send it back to Cascadia Motion. While I had It out, I put it on my test bench. With a DC power supply that was only 40W I was able to turn the inverter on. It drew more current when it started up and pulled the voltage down on the supply but that only lasted a second or two. When it settled it was only drawing 650mA. I was able to connect to it with the RS-232 and using their GUI I found that it now showed multiple hardware failures. And the HW version had changed again. I took a screen shot of that and sent it off to Cascadia Motion support. From those faults they said it’s most likely the power module (IGBT), potentially the gate drive board too, but not the control card and not likely the IO board. The repair could be somewhere between about $1500-$2500, but I would know without sending the unit back. The timing is also an issue. The RMA request said that process of evaluation my take 4 - 6 weeks and the repair could be twice that, even longer if they do not have the spare parts. Since the Rinehart is now removed from the car I went ahead and put the Scott Drive back in because I would like to drive the car now the seasons have changed. I had retained the wiring harness and mechanically did not alter the engine bay so it dropped right in. I did not even change the cooling lines. I had bought all new hardware because Rinehart uses AN fittings and the Scott Drive is barb hose fittings, but I never got a chance to change the fittings. The Scott Drive uses many fewer inputs than the Rinehart so it only took a day to rewire the cross-over box. I started up the Scott Drive and run the Scott Drive GUI. The throttle and brake seemed to still be calibrated with the offset and gain that was in firmware and the motor spun right up when the accelerator was pressed. The regen even slowed the motor spin down with the application of the brakes. I just have to clean up the connections inside the car and then I will be able to take the 320e for a test drive. I will post another blog after I decide what I am going to do with the Rinehart.