User's Manual

SECTION II INSTALLATION

SM 7063 07/97 2-5

2.4 MOUNTING THE CDU

This section details mounting the CDU onto the Mounting Tray or in the AAR Clean Cab Enclosure.

2.4.1 72 VDC / 12 VDC Power Selection Jumper (JP1)

The CDU can be powered from either the standard 72 VDC locomotive power system or a 13.6 VDC

(nominal) power source such as an automobile lighter socket. An internal Power Selection Jumper (JP1)

located on the Base Assembly allows the user to select one power source or the other.

The CDU is shipped with this jumper set to the 72V position

To change the Power Selection Jumper setting, simply remove the CDU’s top cover, remove the jumper

plug, and place it in the desired position as marked on the PCB silk-screen. Replace the top cover.

2.4.2 Installing the CDU onto a Mounting Tray

CAUTION

Prior to connecting any cables to the CDU, it is recommended that the

locomotive Radio Circuit Breaker be turned OFF.

a) Slide the CDU into the keyhole slots in the Mounting Tray.

b) Engage the screw latch at the rear of the CDU.

c) Tighten the screw latch until the CDU is firmly in place. Do not overtighten. Padlock the unit, if desired.

d) Connect the CDU Power cable to the power connector on the CDU.

e) If applicable, connect the CDU Odometer cable to the Axle Alt connector on the CDU.

f) If applicable, connect the CDU Datalogger/Event Recorder cable to the Datalogger/Event Recorder

connector on the CDU.

g) Connect the Antenna cable to the mating RF connector on the CDU.

2.4.3 Installing the CDU into an AAR Clean Cab Enclosure