The electrical swivel center or collector ring assembly is secured by setscrews to a center post which is bolted to the spool
of the air/transmission swivel. This allows the collector ring assembly to remain stationary with the chassis. The outer
portion or brush assembly is spring mounted on two pins which are located on a mounting plate welded to the
air/transmission swivel barrel. This allows the brush assembly to rotate with the superstructure. The springs on the
mounting plate pins allow the swivel to float and not bind when the superstructure rotates.
Electrical power is transferred to and from the carrier and superstructure through the electrical swivel. The swivel has 42
All electrical circuits are protected, and some controlled, from the printed circuit board (circuit breakers) located in the cab
right side panel. The printed circuit board consists of a harness with four connectors, six relays, nine circuit breakers, and
a flasher. The relays are energized to close their contacts any time the ignition switch is in the ON or ACC position.
The instrument panel is located in the cab section of the crane. It contains all of the controls and indicators that the
operator will use during crane operation. Additional information on the instrument panel and it's controls and indicators
can be found in the Operator's Manual TM 5-3810-306-10.
The backup alarm is located above the pintle hook on the carrier. It serves as a warning to personnel that the crane is
traveling in reverse.
Two lights mounted in the crane's superstructure are the cab floodlight and boom floodlight. The cab floodlight is located
on the outside of the cab and is controlled by the operator by a swivel handle inside the cab. The boom floodlight is
mounted on the telescoping boom and is used to illuminate the work area and hook block during night operations.
Sending Units and Switches
The electrical system provides electrical power to a variety of sending units and switches that monitor the systems in which
they are installed. These sending units and switches transmit signals to indicators and warning lights in the operator's cab,
allowing the operator to monitor the system and warn him of impending problems.