Replacing an Assistant Cooling Unit

Impact on the System

During the replacement of an assistant cooling unit, system performance and reliability are compromised. Therefore, you are advised to replace an assistant cooling unit during off-peak hours.

Prerequisite

• A replacement assistant cooling unit is ready.
• The assistant cooling unit that you want to replace has been located.

You can locate a component in either of the following ways:

• Locating a component based on alarms in DeviceManager: On the Alarms and Events page of DeviceManager, view the help information and determine the ID of the component to be replaced. Then locate the component at your site based on its ID.
• Locating a component based on the status of its Running/Alarm indicator: For details about the indicators on different components, see Indicator Introduction of each component in the Product Description specific to your product model and version.

• Each assistant cooling unit is equipped with three fan modules. Before replacing an assistant cooling unit, ensure that the fan modules of the other assistant cooling unit work properly.

Precaution

• Remove and insert an assistant cooling unit with even force. Excessive force may damage the appearance or connectors of the assistant cooling unit.
• Remove only one assistant cooling unit at a time.
• An assistant cooling unit must be replaced within five minutes. Otherwise, the system heat dissipation is compromised.
• A controller enclosure's controller and assistant cooling unit (ACU) have the same appearance, but can be distinguished according to the silkscreen in the lower left corner of the front panel. CTM refers to a controller and ACU refers to an assistant cooling unit.

Tools and Materials

• ESD wrist strap
• ESD bag
• Labels

Procedure

1. Check status before replacement.
   1. Check system status.

      Start SmartKit and choose Routine Maintenance > Health Check. On the Health Check page, perform inspection as instructed. For details, see Checking System Status.

      If any items fail the inspection, rectify the faults by performing the recommended actions in the inspection reports. Ensure that all other parts except the parts to be replaced are working properly.

   2. Check the status of the parts to be replaced.

      Start SmartKit and choose Parts Replacement > Parts Replacement. On the Parts Replacement page, click FRU Replacement. Then complete the check before the replacement as prompted. For details, see Replacing an FRU.

      You can proceed to next steps only when all items pass the pre-replacement check and the replacement page is displayed. If any item fails, rectify the fault as prompted.

2. Wear an ESD wrist strap.
3. Press the latch on the assistant cooling unit to release the handles and pull out the assistant cooling unit, as shown in Figure 5-17.
   Figure 5-17 Removing an assistant cooling unit
   

4. Take the spare part out of its ESD bag.
5. Remove the three fan modules from the original assistant cooling unit and install them on the replacement assistant cooling unit.
   1. Press the latch on the panel, open the panel, and pull out the three fan modules one by one, as shown in Figure 5-18.
      Figure 5-18 Removing fan modules
      

   2. Insert the three fan modules into the replacement assistant cooling unit and close the panel, as shown in Figure 5-19.
      Figure 5-19 Installing fan modules
      

6. Place the removed assistant cooling unit into an ESD bag.
7. Fully open the handles of the replacement assistant cooling unit, insert the assistant cooling unit into the empty slot until it clicks into place, and close the handles, as shown in Figure 5-20.
   Figure 5-20 Installing an assistant cooling unit
   

8. Wait about one minute (a maximum of five minutes) and check the status of the Power and Alarm indicators on the assistant cooling unit to determine whether the assistant cooling unit has been successfully installed, as shown in Figure 5-21.
   • If the Power indicator is steady on and the Alarm indicator is off, the assistant cooling unit has been successfully installed.
   • If the Power indicator is off or the Alarm indicator is steady on, the newly installed assistant cooling unit is faulty, the assistant cooling unit slot is faulty, or the assistant cooling unit is incorrectly installed.
   Figure 5-21 Indicators on an assistant cooling unit
   

9. Confirm the replacement.
   1. Perform a post-replacement inspection.

      After the parts replacement, return to the SmartKit page and click Replaced. Then complete the parts check after the replacement as prompted.

   2. Check system status.

      On the Parts Replacement page, click Inspection to check the system status again. If any item fails inspection, rectify the fault based on the suggestions in the inspection report.

   3. After the preceding procedure is complete, check services on the host for storage-related errors.

Follow-up Procedure

After an assistant cooling unit is replaced, label it to facilitate subsequent operations.