Checking the grounding of a SAN Volume Controller, the uninterruptible power supply, and the redundant ac-power switch

Ensure that you understand how to check the grounding of a SAN Volume Controller, the uninterruptible power supply, and the optional redundant ac-power switch feature.

To test the grounding of a SAN Volume Controller node, perform the following steps. Follow the steps for the SAN Volume Controller configuration that you are using. Before you start, confirm that you know the SAN Volume Controller model type, the uninterruptible power-supply type, and whether you are using redundant ac power. Determine the location of the signal cables that are attached to the SAN Volume Controller.

When you are asked to test the grounding continuity, use your local procedures to perform the test. The test is successful if the measured resistance is 0.1 ohm or less.

Attention: Some electrical circuits can be damaged if the external signal cables are present at the SAN Volume Controller while it is undergoing a grounding test.
  1. Ensure that the SAN Volume Controller node is powered off. See MAP 5350: Powering off a SAN Volume Controller node IBM® System Storage SAN Volume Controller Troubleshooting Guide.
  2. If the uninterruptible power supply is a 2145 UPS, ensure that other SAN Volume Controller nodes that are powered from the uninterruptible power supply are powered off.
  3. Use the power button to power off the uninterruptible power supply.
  4. Disconnect all signal cables from the SAN Volume Controller node, which includes the following cables:
    • The fibre-channel cables
    • The Ethernet cable or cables
    • The serial cable that is connected to the uninterruptible power supply
  5. Disconnect all signal cables from the uninterruptible power supply. If the uninterruptible power supply is a 2145 UPS, there might be multiple signal cables.
  6. If the uninterruptible power supply is a 2145 UPS, disconnect any power cables that are connected to SAN Volume Controller nodes, except the one that is being tested.
  7. If redundant ac power is not used, disconnect the uninterruptible power-supply power cable from the site power-distribution unit.
  8. If redundant ac power is used, turn off any SAN Volume Controller that is being supplied from the redundant ac-power switch, and remove the power cable to this system from the redundant ac-power switch.
  9. If redundant ac power is used, disconnect both input power leads from the site power distribution units.
  10. If redundant ac power is not used, test the grounding continuity between a conductive area on the SAN Volume Controller frame and the ground pin on the plug of the uninterruptible power-supply input-power cable.
  11. If redundant ac power is used, test the grounding continuity between a conductive area on the SAN Volume Controller frame and the ground pin on the plug of the main power cable of the redundant ac-power switch. If the test is successful, test the grounding continuity between a conductive area on the SAN Volume Controller frame and the ground pin on the plug of the backup power cable of the redundant ac-power switch. Both tests must be successful.
  12. After you have completed testing the grounding continuity, perform one of the following procedures, depending on the outcome of the test.
    • If the test is successful, reconnect any cables that were removed, and power on any uninterruptible power-supply units and SAN Volume Controller nodes that were powered off.
    • If the test was not successful, ensure that all cables are securely connected. If the test still fails, test the individual system components. Before you test the individual components, remove all cables from the components. If any component test fails, replace the component. After each component has been tested and the failing ones have been replaced, repeat the complete system test by returning to step 1.
      Test the components in the following order:
      1. The SAN Volume Controller node, from the frame to the ground pin of the input power receptacle
      2. The uninterruptible power supply from the ground pin of the input power receptacle to the ground conductor of the output power receptacle
      3. If used, the redundant ac-power switch from the ground pin of the main input power receptacle to the ground conductor of the output power receptacle, and from the ground pin of the backup input power receptacle to the ground conductor of the output power receptacle
      4. The SAN Volume Controller node to uninterruptible power-supply power-cable assembly, between the two ground conductors of the power cable
      5. The uninterruptible power-supply input-power cable, between the two ground conductors of the power cable
      6. If used, the redundant ac-power switch main input-power cable, between the two ground conductors of the cable
      7. If used, the redundant ac-power switch backup input-power cable, between the two ground conductors of the cable
Parent topic: Inspecting the SAN Volume Controller for unsafe conditions
Parent topic: Maintenance procedures
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