Usage:
STEP 1. Check Field Switch
Test Procedure:
Verify that the switch to the generator field coil is closed and not intermittent.
Expected Results:
Field switch is closed, and not intermittent.
STEP 2. Check Reverser
Test Procedure:
Verify that reverser is outputting the correct voltage for its state (FORWARD or REVERSE).
Expected Results:
Reverser is in FORWARD or REVERSE and is outputting correct voltage.
STEP 3. Check Engine Response to Throttle
Test Procedure:
Move notch selector to a notch with an engine speed different from idle speed.
Expected Results:
Engine accelerates to proper speed for the notch selected.
STEP 4. Check Load Control Inputs to Control Box
Test Procedure:
Close field switch. Put reverser in FORWARD or REVERSE. Put notch selector in a notch other than idle. Observe the diagnostic lamps which are visible at the Locomotive control Box lid.
Expected Results:
There are no FAULT indications. GENERATOR LOAD lamp is ON. WHEEL SLIP lamp is OFF.
STEP 5. Check Load Control Inputs to Control Box
Test Procedure:
Use a digital multimeter (Caterpillar Service Tool 6V3030) to measure the DC current through the generator exciter coil as diagrammed in Figure 1 or Figure 2, depending on locomotive system configuration.
Use the multimeter to measure the DC voltage across the generator exciter coil as diagrammed in Figure 3 or Figure 4.
Use the multimeter to measure the DC voltage between BATTERY + and BATTERY - which are shown on Figures 1-4.
Expected Results:
The exciter coil DC current is greater than zero and constant. The exciter coil voltage is greater than zero and less than the Battery Voltage and constant.
A = DC AMMETER (CATERPILLAR 6V3030) FIGURE 1: EXTERNAL CONNECTIONS FOR EXCITER SINK MODE CURRENT MEASUREMENT
A = DC AMMETER (CATERPILLAR 6V3030) FIGURE 2: EXTERNAL CONNECTIONS FOR EXCITER SOURCE MODE CURRENT MEASUREMENT
± V = DC VOLTMETER (CATERPILLAR 6V3030) FIGURE 3: EXTERNAL CONNECTIONS FOR EXCITER SINK MODE VOLTAGE MEASUREMENT
± V = DC VOLTMETER (CATERPILLAR 6V3030) FIGURE 4: EXTERNAL CONNECTIONS FOR EXCITER SOURCE MODE VOLTAGE MEASUREMENT
STEP 6. Check for proper rack sensor calibration.
Test Procedure:
Perform Rack Sensor Calibration using Service Procedure D.
Expected Results:
Rack Sensor was properly calibrated.
STEP 7. Check for Proper Voltage and Current Sense inputs
Test Procedure:
With the engine running and free to load, set the throttle to apply light load. Measure the generator voltage. With Connector J1 connected to the Control box, measure the DC voltage applied by the locomotive electrical system to Connector J1 pin 11 (Voltage Sense Input) with respect to - Battery Voltage. Measure the generator current. With connector J1 connected to the Control box, measure the DC voltage applied by the locomotive electrical system to Connector J1 pin 10 (Current Sense Input) with respect to - Battery Voltage.
Expected Results For AC generators:
The voltage at J1 pin 10 is less than 55 VDC and is:
The voltage at J1 pin 11 is less than 55 VDC and is:
Expected Results For DC generators:
The voltage at J1 pin 10 is less than 55 VDC and is:
The voltage at J1 pin 11 is less than 55 VDC and is:
STEP 8. Check for External Short Circuit
Test Procedure:
Troubleshoot locomotive electrical system for short circuit in wiring between Locomotive Control box and exciter coil or a short circuit of the exciter coil itself.
Expected Results:
No short circuits found in electrical system or exciter coil.
STEP 9. Check for Generator Load Command
Test Procedure:
With the Locomotive Control box connected to the wiring harnesses, measure the DC voltage that is applied to the Generator Load input (Connector J1, pin1) with respect to the Interface (-) Battery Voltage (Connector J1, pin 15). Also measure the Interface (+) Battery Voltage (Connector J1, pin 14) with respect to Interface (-) Battery Voltage.
Expected Results:
The Generator Load input voltage is within 8 VDC of the Interface (+) Battery Voltage and is constant.
STEP 10. Check for Wheel Slip Signal
Test Procedure:
With the Locomotive Control box connected to the harnesses, measure the DC voltage that is applied to the Wheel Slip input (Connector J1, pin 2) with respect to the Interface (-) Battery Voltage (Connector J1, pin 15). Also measure Interface (+) Battery Voltage (Connector J1, pin 14).
Expected Results:
The Wheel Slip input voltage is no more than 8 VDC below Interface (+) Battery Voltage and is constant.
