Water leak problems

Use this information to resolve issues related to water leaks.

The SD650 design is robust, and is unlikely to leak. If the water is observed outside of the enclosure, make sure the both enclosure and rack power supplies have been disconnected. If no water is observed outside of the enclosure, but there is a suspicion of a water leak in the enclosure or in one of the six compute trays, complete the following steps to determine the source of the leak. The enclosure is equipped with a pair of drip sensor assemblies to help detect any water leaks.
Note: A small leak may not reach either of the drip sensors to trigger a warning. Visual confirmation of a small leak may be required.

Suspicious leakage symptoms

The following situations might occur due to leakage problems:
  • Processor over temperature error indicated by the System Error "!" LED being solid ON at the front of the node

  • One or more of the nodes shut down unexpectedly

  • Enclosure FPC management may report Leak_Snsr1_FAULT or Leak_Snsr2_FAULT

Possible causes of a leak:
  • Leak at quick connects during installation or removal procedures

  • Leak in the water loop tubing

Complete the following steps in order until you are able to isolate the cause of the potential leak:
  1. Check enclosure FPC messages to see if any leakage warnings have been reported. See Messages and Codes Reference for more information.

  2. Walk to the rear of the rack and visually check the status of each enclosure's left and right side drip sensor LEDs.

    Users usually have multiple enclosures per rack. Each enclosure has two drip sensors.
    Note: Each enclosure has two drip sensors that should turn on a yellow LED visible through a hole located in the lower left leg of the lower EMC shield if the sensor detects moisture in its drip sensor catch basin.
    Figure 1. Drip sensor LED
    Drip sensor LED
    Table 1. Drip sensor LED
    1 Drip sensor LED (yellow)

  3. Visually check the drip sensor catch basin for any moisture.

    1. Remove the lower left EMC shield in the front of the left drip sensor.

      Figure 2. Lower left EMC shield removal
      Lower left EMC shield removal
    2. Use a flashlight to visually inspect the plastic catch basin for any moisture.

    3. Re-install the EMC shield.

      Figure 3. Lower left EMC shield installation
      Lower left EMC shield installation
    4. Repeat steps for the right side drip sensor catch basin.

  4. Power down all nodes either through the OS or by pressing and holding the power button for five seconds.

    Note: Green Power LED for each node (two per compute tray) should be blinking to indicate the nodes are in standby state.
  5. Disconnect power cords from all six enclosure power supplies.

    Important: Fully disconnect the power to the entire enclosure prior to attempting to identify a leak within an enclosure.
  6. Check the water loop for any moisture.

    1. Remove the top node (bays 11&12) from the enclosure (see Remove a DWC tray from the enclosure), place it on a stable work surface, remove the cover (see Remove the tray cover), and carefully inspect the entire water loop (both rubber and copper tubing) for any signs of moisture. Re-install the compute tray into enclosure (see Install a DWC tray in the enclosure).

    2. Repeat steps for the tray in bays 9 and 10.

    3. Repeat steps for the tray in bays 7 and 8.

    4. Repeat steps for the tray in bays 5 and 6.

    5. Repeat steps for the tray in bays 3 and 4.

    6. Note: It is important to visually inspect the bottom of the enclosure with a flashlight prior to re-installing the bottom most tray (bays 1 and 2) into the enclosure.

      Repeat steps for the tray in bays 1 and 2.

  7. If you are unable to identify the problem in the steps above, then you may need to replace one or more of the tray water loops (see Water loop replacement). Contact Product Engineer for the further assistance.

Important: The procedures above only cover the Lenovo DWC solution (from the Eaton Ball valves up through the manifold and into the enclosures and compute trays). If your datacenter Cooling Distribution Unit experiences repeated or frequent low water alerts then you should inspect the data center plumbing between the cooling distribution unit and the Lenovo DWC solution (rack).