Speed Control

i. Reassembly.

linkage to the shaft in the speed control box assembly.

Reassemble the parts in the

(fig. 3-9.) The action of the spring holds the arm in the

contactor box by installing the mounting hardware and

position shown when no pressure is applied to the pedal.

other parts removed. (fig. 3-3.) Be sure an insulator is

(2) The arm determines the position of the

placed under each contactor when it is remounted to the

actuator, which is held by the set screw to the

control unit box.

potentiometer shaft.

In the up position, the

3-6. Speed Control

potentiometer provides a resistance of about 15.000

a. General.

ohms.

(1) The speed control consists of the

(3) When the pedal is depressed, the actuator

accelerator pedal linkage and the speed control box

rotates clockwise, turning the potentiometer shaft and

assembly.

The box assembly includes the speed

releasing the microswitch plunger.

This rotation

interlock microswitch and the speed potentiometer. The

decreases the resistance of the potentiometer.

speed potentiometer should be adjusted prior to the

(4) Maximum depression of the pedal is

adjustment of the inching control on the control unit.

reached when the arm bears against the down stop. At

(2) Before working on the speed control;

this point, the potentiometer provides a resistance of

disconnect battery and discharge capacitors (para 2-5).

about 40 ohms.

b. Description.

(1) The accelerator pedal is connected through

3-16