• If the load on the active PSU is more than 50 percent, then the redundant PSU is switched to the active state.• If the load on the active PSU falls below 20 percent, then the redundant PSU is switched to the sleep state.You can configure the hot spare feature by using the iDRAC settings. For more information about iDRAC settings, see the IntegratedDell Remote Access Controller User’s Guide available at Dell.com/idracmanuals.Removing a redundant power supply unitPrerequisitesCAUTION: Many repairs may only be done by a certified service technician. You should only perform troubleshooting andsimple repairs as authorized in your product documentation, or as directed by the online or telephone service and supportteam. Damage due to servicing that is not authorized by Dell is not covered by your warranty. Read and follow the safetyinstructions that are shipped with your product.CAUTION: The system requires one power supply unit (PSU) for normal operation. On power-redundant systems,remove and replace only one PSU at a time in a system that is powered on.1. Follow the safety guidelines listed in the Safety instructions section.2. Disconnect the power cable from the power source.3. Disconnect the power cable from the PSU and remove the straps that bundle and secure the system cables.4. Unlatch and lift the optional cable management arm if it interferes with PSU removal. For information about the cablemanagement arm, see the systems rack documentation at Dell.com/poweredgemanuals.StepsPress the release latch and pull the PSU out of the chassis.Figure 78. Removing and installing a redundant PSU1. release latch 2. PSU connector3. power connector 4. PSU handleNext stepsInstall the PSU.NOTE: If you are removing the PSU permanently, install a PSU blank.Related linksInstalling a redundant power supply unitInstalling the power supply unit blank117
