DRIVE 9J6506 - Caterpillar

Remove the shield wire nut (1).
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Remove the six bolts (2) from the two top covers (3) and the eight bolts (4) from front covers Note: Measure the voltage between each of the 3- phase conductors and frame ground after the enclosure cover is removed. Do not make personal contact with the exposed contacts until you have verified that there is little or no voltage present at the exposed conductors. Verify little or no voltage (50 VDC or less) is present before any contact is made with the conductors. Refer to the Operation and Maintenance Manual for this machine.
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Check the compartments for moisture, oil, and coolant. Check for proper cable installation to the inverter lugs. If the terminal ends are not squarely seated on the lugs, loosening will occur over time. Remove nuts (5) ( 6) and cable assemblies (7). Test Procedure
Connect the negative probe. Refer to Table 1
Connect the positive probe. Refer to Table 1
Verify that the exposed ends of the conductor are not in contact with any other conducting surfaces.
Turn on the Inductance (LCR) Tester. Ensure the meter is in Auto Range mode (8) and set to 1kHz measurement frequency (9). The tester should automatically change to "L" inductance measurement (10) when connected between two stator phase cables. If the meter does not, press the ZLCR button (11) until "L" is displayed on the screen.
Allow the inductance reading to stabilize, typically 5-10 seconds. Record the inductance measurement in Table 1. Electric Drive Motors with the rotors installed will have a measurement in milliHenries (mH). Illustration four shows the units (12) of the tester in micro Henries (µH).
Test the remaining conductors in the assembly by repeating steps 1-5. Repeat for the other motor and document results in Table 53.
Calculate the percent difference of the Inductance measurements by filling out the remaining lines in Tables 52 and 53.
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Table 1
Worksheet for Testing the Inductance of the Motor 1 Windings
Line Negative Probe Positive Probe Motor 1 Actual Result Motor 1 Expected Result
1 Conductor B Conductor A milliHenries (mH)
2 Conductor B Conductor C milliHenries (mH)
3 Conductor C Conductor A milliHenries (mH)
4 Maximum Of Lines 1, 2, & 3
5 Minimum Of Lines 1, 2, & 3
6 Calculate (Line 1 + Line 2 + Line 3) / 3
7 Calculate (Line 4 - Line 5) / Line 6 Less than 0.2 (20%) Note: Be sure to include the measurement units in your results above. Inductance measurement for the D7E electric drive motors with the rotors installed should be in milliHenries (mH). 1,000 milli-Henries = 1 Henry.
Table 2
Worksheet for Testing the Inductance of the Motor 2 Windings
Line Negative Probe Positive Probe Motor 2 Actual Result Motor 2 Expected Result
8 Conductor B Conductor A milliHenries (mH)
9 Conductor B Conductor C milliHenries (mH)
10 Conductor C Conductor A milliHenries (mH)
11 Maximum Of Lines 8, 9, & 10
12 Minimum Of Lines 8, 9, & 10
13 Calculate (Line 8 + Line 9 + Line 10) / 3
14 Calculate (Line 11 -