How to install a speed control potentiometer in T-Rex™ and T-Rex™ Jr. Rotary Extractors.

Parts Needed:

  • Part # P501A - blue faceplate
  • Part # E363A - potentiometer
  • Part # E405A - potentiometer knob
  • Part # E382 - speed control board
  • Part # E506 - slide terminal, female 14 gauge
  • 2x Part # H230 - screws

Tools Needed:

  • 1/8" Allen wrench
  • Phillips screwdriver
  • Wire cutter/stripper
  • Wire crimper

1. Remove the back cover and the blue front cover from the handle.

The back cover is removed using the 1/8" Allen wrench. Once the back cover is off, remove the three Phillips head screws holding the blue front cover on.

2. Remove the rectifier.

Unplug all the wires from the rectifier. Remove the screw holding the rectifier in place and remove the rectifier.

3. Install the new Speed Control Board into place.

Place the Speed Control Board into position as shown in the picture. Use the two included Phillips screws to mount the board in place as shown.

4. Plug the wires into the Speed Control Board.

Cut the connector off of the white wire. Strip the wire coating back about 1/2". Crimp on the included spade connector. Plug in the black, white, red, and blue wires as shown in the image below.

5. Install the potentiometer into the faceplate.

Place the clear washer as shown in the center of the inside of the faceplate, along the bottom. Mark where to drill the hole for the potentiometer. Drill a 3/8" hole where marked in the faceplate. Slide the clear washer onto the potentiometer knob and make sure the little nub on the potentiometer fits into the smaller hole on the washer. Place the knob through the faceplate hole and fasten with the washer and nut.

6. Plug in the wires from the potentiometer.

Take the blue front cover with the potentiometer installed. Plug the red, black, and blue wires from the potentiometer, labelled P1, P2, and P3 respectively, into the terminals on the control board which are also labelled P1, P2, and P3. See the image below.

7. Test.

Double-check the knob settings. Correct positions are shown in the image above. Once correct, plug the machine in and make sure the speed adjusts when you turn the potentiometer knob and the motor is spinning clockwise.

8. Re-install the blue front cover and the rear cover.