One motor contactor (on the left) energized by the key-switch.
The parallel contactor (right, top) is the first
step when the accelerator pedal is depressed lightly. It switches the front
and rear 24volt packs in parallel for 24volts on the motor. This step is only
used for starting in first gear or in reverse. Further depressing the pedal
releases the parallel contactor and closes the series contactor (lower right)
to place the front and rear packs in series for 48volts on the motor.
The wide metal strip between the top contactors is the motor fuse.