Sunday, November 16, 2008

Charger, Controller and Contactor Mounting

Today involved trying to mount the major electrical components to the car.

Before covering up the transmission, I thought it would be a good idea to fill it with transmission fluid. The Honda Civic specifies 10w-30 oil for the transmission. Since the fill hole is really hard to access, I used a funnel attached to a plastic hose to get the oil in.

Before mounting the plastic panel to mount the EV components on, I drilled two 3/16" holes, 6 3/4" apart on the passenger side battery support. This will be used to mount the large 3-ohm resistor used by the charging system.

I still haven't figured out the hold-downs for the cars 12V auxiliary battery or the extra battery in the rear trunk. Since access will be more difficult after I install the EV components, I drilled a 5/16" hole (top center in picture) in the passenger side front battery support iron. I think I can use 5/16" all-thread with some angle iron to get this hold-down working.

Okay, on to mounting the control board plastic. As we stated before, this plastic is 1/2" thick, 28" long and 8 1/2" wide. I clamped it in place with a plastic clamp to prevent marring the surface. I placed the main contactor near the right edge, approximately centered front-to-back.
With the the plastic and contactor in place, I scratched circles in the plastic for the two 3/16" contactor mounting holes and underneath the plastic in all the 1/4" mounting holes from the angle-iron that juts out.

Afterwards, I removed the plastic, and drilled out all the holes (3/16" for the contactor, 1/4" for the board mounts). I used a countersink bit to taper the bottom of the contactor holes so the bolt-heads would be flush with the bottom side of the plastic. I also countersunk the top-side of all the 1/4" holes so that the main mounting bolt heads would be flush with the top-side of the plastic. By making all these bolt heads flush, I don't interfere with any components or support angle-iron.

Here's the plastic installed on the angle-iron supports and the contactor in place. I used six 1/4" flathead bolts 1" long for the main supports and two 10-24 x 1" long flat-head bolts to mount the contactor. All bolts were held in place with nylock nuts.

With the plastic mounted, I placed the charging unit and controller unit on the plastic. The front edge of each component was 3/4" from the front edge of the plastic. The charger was on the passenger side and its heat-sink fins aligned with the inside vertical wall of the passenger-side angle-iron support. The controller unit sat between the charger and the contactor with 1/4" of clearance between the heatsinks. With the two units in place, I dropped a 1/4" bolt down through the mounting holes and marked the plastic.

After removing the units, I drilled out the 1/4" holes. The hole closest to the passenger seat had to go through the plastic and the metal support. After drilling these holes, I bolted the components to the plastic using 1/4"-20 x 4" long bolts with washers and nylock nuts underneath. The rear bolt on the motor controller was very close to the transmission housing, so I added some spacer washers to raise up the bolt a bit to prevent interference.

Whoops! I accidentally mounted the contactor with the activation terminals on the high-voltage side, so I had to disassemble the whole thing, flip the contactor around, and re-install it (shown correctly here).

Here's the final installation with the two main EV components and the contactor on the right.

The last item of the day involved installing the large 3-ohm (90 watt!) power resistor on the passenger side angle-iron support. This simply used two 10-24 round-head bolts 1" long and nylock nuts. I thought it would be easier to wire with the terminals up, so we'll see.

Next up: mounting all the small EV control boxes


Unknown said...

If you have to shift the transmission much, I would recommend spending the $20 or so to get 2 quarts of Honda MTF and use that instead of 10w-30. That's now the recommended fluid for all Honda manual transmissions and in my experience it really does work a lot better than 10w-30 motor oil.

TimK said...

Hi Aaron,
Thanks for the heads up. I'll definitely look into that after I finish up the wiring.