Replacing a Soleq EVcort Motor Controller

By Tim Wong

Installing the Kelly Controller

This is just a page chronicling what I did to change controllers: YOU SHOULD NOT DO ANYTHING IN THIS WEB PAGE WITHOUT BEING 100% CONFIDENT IN YOUR ELECTRICAL ABILITIES!!! THIS IS NOT A MANUAL AND NO GUARANTEE OF ANY KIND IS IMPLIED. IT IS INFORMATIONAL ONLY. DON'T TOUCH YOUR CAR IF YOU DON'T KNOW EXACTLY WHAT YOU ARE DOING!! HIGH VOLTAGE IS VERY DANGEROUS IF YOU DON'T KNOW WHAT YOU ARE DOING, JUST AS GASOLINE IS VERY DANGEROUS IF YOU DON'T KNOW WHAT YOU ARE DOING.

Removing old controller

I unplugged the main connector and let it sit for 24 HOURS to let charge drain. I also checked EVERY part's voltage with my voltmeter to system ground and chassis ground before removing it.

First I removed the bumper by removing the side marker lights, then the headlights, and the small cover between the headlights. Once the headlights are removed, the six nutted bolts holding the bumper on are visible. Once the bumper is removed, the controller is visible.

I removed the controller and then took out all the electrical contents. Kind of sadů The amazing work and innovation of Mr. Shunjiro Ohba reduced to junk in a box.

I also removed the two huge chokes or inductors, weighing about 15lb each.

Installing the Kelly controllers

I then installed the two Kelly controllers as well as the small 12V-12V dc-dc converters. The Kelly controllers are isolated from the box, which is connected to chassis ground with a Burgquist thermally conductive insulating pad GP1500R. You can get it from Digikey; it is a bit expensive. I used nylon bushings from the Soleq electronics to mount it.

Here are the system wiring diagrams (most part numbers are also here):

Click here for power schematic pdf file

Click here for control schematic pdf file

Wiring up and Removing Old Parts

I also removed the Soleq volt and ammeters. I would have liked to keep them, but they were integral to the Soleq controller; at least I thought they were. I have a battery monitoring system I designed, so I didn't need it. Here is a link to the battery monitor:

EV Battery Monitor Page Link

To thread the cables into the cabin I pulled the military connectored cables as far into the cabin as I could, then taped the new cables to it, and pulled them both into the engine compartment. I mounted the status LEDs here below the radio.

I mounted the field control knob/pot here:

I also removed the Soleq contactor box, and removed all the capacitors. They were heavy! I left the Soleq main contactor, which has a 100VDC coil, as they are expensive to replace; and why do it.

I configured the key switch to run off the battery in the ACC position, turn on the DC-DC converter in the ON position, and close the main contactor in the START position (using a latching relay). See the schematics above or in the Technical Specifications section for detailed information. In the start position, the main contactor supplies 108V to the Kelly controllers and the latching relay supplies 12V logic to the Kelly controllers via the small DC-DC converters.

I removed the old 1K potentiometers from the soleq pot box, and added two new bourns 5kohm single turn high cycle potentiometers (from digikey, Bourns part # 6639S-1-502). They have to be adjusted to have the voltage to the controllers go from 0-5V for accel and regen. I also added enable switches to the accel and regen levers on the potentiometers. I don't think these are high cycle switches, so I should change them.

The Kelly controllers are configurable via a serial port. I made a small interface box to allow for configuring the controllers without removing the controller box. See the Technical Specification page for the armature and field controller configurations I used.

I also had previously replaced the Soleq DC-DC converter with a Brusa.