Fault Code CA6693

General information on system checkout

The electrical system checkout procedures are intended to help the technician diagnose problems in the 24V control and lighting systems. The technician should read the checkout procedures to become familiar with the procedures and all the warnings and cautions before performing any steps. The checkout procedures begin by checking the basic system before checking individual components. A data sheet is included in this section to record the test information obtained during the electrical system checkout procedure. The data sheet is designed to be printed or copied, then used during the checkout procedure.

This checkout procedure must be performed by qualified, trained personnel that have knowledge of the operation of the truck and the stored energy systems. Personnel must observe all established precautions where the checkout procedure is being performed. All potentially stored energy within the truck must be released before performing any troubleshooting. DANGEROUS VOLTAGE LEVELS ARE PRESENT WHEN THE TRUCK IS RUNNING AND CONTINUE TO EXIST AFTER SHUTDOWN IF THE REQUIRED SHUTDOWN PROCEDURES ARE NOT FOLLOWED. Before attempting repairs or working near drive system components, the following precautions and truck shutdown procedure must be followed: • DO NOT step on or use any power cable as a hand hold when the engine is running. • NEVER open any electrical control cabinet covers or touch the retarding grid elements.

Additional drive system safety checks must be performed by a technician trained to service the system before working on drive system components. • ALL removal, repairs and installation of drive system electrical components, and cables must be performed by an electrical maintenance technician properly trained to service the drive system. • IN THE EVENT OF A DRIVE SYSTEM

MALFUNCTION, a qualified technician must inspect the truck and verify the drive system does not have dangerous voltage levels present before repairs are started. • THE DC LINK VOLTAGE LIGHTS MUST NOT BE

ILLUMINATED WHEN TEST OR REPAIRS ARE

INITIATED. It requires approximately five minutes after the truck is shut down before the

DC link voltage has dissipated.

Power cables must be cleated in wood or other non-ferrous materials. Do not repair cable cleats by encircling the power cables with metal clamps or hardware. Always inspect power cable insulation prior to servicing the cables. Replace cables that have broken insulation.

Truck shutdown procedure

Energizing the drive system is not dependent on the position of the directional control lever or actuation of the accelerator pedal. If generator field contactor (GF) switch (2, Figure30-1) is in the NORMAL (ON) position and the engine is running, the drive system link is "hot" with dangerous voltage. Normal operation of the drive system at shutdown should leave the system safe to operate. In the event of a system failure, performing the following procedure will ensure that hazardous voltages are not present in the drive system. 1. Before shutting down the engine, verify the status of the drive system warning lights in the cab. If any of the drive system warning lights are illuminated, do not attempt to open any cabinets, disconnect any cables, or reach inside the retarding grid. 2. If all drive system warning lights are off, move the directional control lever to PARK and turn the key switch OFF to shut down the engine. 3. Chock the tires to prevent possible roll away. 4. After the engine has been off for at least five minutes, verify that capacitor charge lights (3) and (4) on the front of the main control cabinet are off. This indicates that the DC link voltage has been discharged. 5. To ensure that the DC link will not be reenergized, move generator field contactor (GF) switch (2, Figure30-1) to the CUTOUT (OFF) position. 6. At the battery isolation station, move both the starter disconnect switch and the main battery disconnect switch to the OFF position.

Certain drive system failures can result in a condition where one or more capacitors can remain in a charged state even though the DC link voltage lights are off.

Because a danger can still exist when the DC link voltage lights are off, it is necessary to manually discharge the capacitors before touching or servicing drive system components. Only authorized service personnel are allowed to service the drive system.

Refer to the drive system shop manual for safety rules and procedures regarding the servicing of the drive system. Adhere to the proper procedures for disabling, checking and discharging the drive system.

Required software and tools

Several tools are required for the electrical system checkout procedures. •Electrical system schematic •Service computer (1 GHz processor, 512 MB RAM minimum) with Windows® operating system (XP or later) •RS232 serial cable (one male DB9 connector, one female connector) •Ethernet cable •WebPTU software •Drive system electrical schematic •Vehicle Test Instructions (VTI) •Megger - 0- 1500 volt (0-2000 Mega ohms) •Several jumper wires •Multimeter (1,000V)