Performing Potential Equalisation Measurement (Four-Wire Measurement)

Information 

Observe the following specifications for all work described:

• country-specific, national, legal and official regulations,
• local restrictions and export restrictions,
• manufacturer's specifications from component and vehicle manufacturers,
• component-specific specifications.

These strict specifications apply in particular:

• Storage, installation and removal, transport and disposal of vehicles, assemblies, operating materials and auxiliary materials,
• handling of defective and potentially hazardous vehicles as well as assemblies,
• handling of battery electric vehicles and high-voltage components.

For this purpose, take into account relevant and qualified information sources such as local authorities, responsible importers, associations and specialist website. Deliver items to be disposed of only to authorised reception points.

Information 

A potential equalisation measurement must always be carried out if a high-voltage component or potential equalisation line was loosened or removed and installed. The potential equalisation measurement must be performed on the loosened or removed and installed high-voltage component or potential equalisation line.

Information 

The instructions in the Tester  take precedence, since the description may be different with later Tester releases.

The procedure described here has been structured in general terms. Different text or additional information may appear in the Tester  .

1. > VAS 6558A - High-voltage testing module  must be connected to > 9900 - PIWIS Tester 3  . Then, start the Tester.
2. Select Measurement and test equipment  in the overview.
3. Select the HV system  measurement program in the Measurement programs  menu.
4. Select the Potential equalisation measurement  menu.
5. Perform self-test on > VAS 6558A - high-voltage testing module  according to menu guidance.
6. Go back to the Overview  .
7. Enter an operating range for the 1000 mA  test current.
8. Connect Kelvin clamps (red and black) from > VAS 6558A/27 - set of Kelvin clamps and test probes  to test cables (red and black) for > VAS 6558A - high-voltage testing module  .

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   Kelvin clamps

   Loosened or removed and installed high-voltage components have their own voltage equalising cable. Continue with Step 9. Potential equalisation measurement from high-voltage component to body 

   Loosened or removed and installed high-voltage components do not have their own voltage equalising cable. Continue with Step  12. Potential equalisation measurement from high-voltage component to high-voltage component 

   Potential equalisation measurement from high-voltage component to body

9. Attach Kelvin clamp (black) from > VAS 6558A/27 - set of Kelvin clamps and test probes  at an electrically conductive point on a high-voltage component with its own potential equalisation line.

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   High-voltage component with potential equalisation line (shown as an example)

10. Attach Kelvin clamp (red) from > VAS 6558A/27 - set of Kelvin clamps and test probes  at an electrically conductive point on the high-voltage component to be tested.

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    High-voltage component to be tested (shown as an example)

11. Press on test probes and start the test.

    Potential equalisation measurement from high-voltage component to high-voltage component

12. Attach Kelvin clamp (black) from > VAS 6558A/27 - set of Kelvin clamps and test probes  at an electrically conductive point on a high-voltage component.
13. Attach Kelvin clamp (red) from > VAS 6558A/27 - set of Kelvin clamps and test probes  at an electrically conductive point on the high-voltage component to be tested  .
14. Press on both test probes and start the test.

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

Sample illustration