Installing an AC power supply unit or cooling fan module1. Slide the power supply unit or cooling fan module into the chassis until the release tab clicks intoplace.2. Connect the power cable to the power supply unit or cooling fan module and plug the cable into apower outlet.3. Secure the power cable using the Velcro strap.Figure 14. Securing the power cable1. Velcro strapCAUTION: When connecting the power cable, secure the cable with the Velcro strap.NOTE: If the enclosure is powered on, all the power supply LEDs remain off until the AC powercable is connected to the power supply unit or cooling fan module and the power switch isturned on.4. Turn on the power supply unit or cooling fan module.About DC power supply unitsAn MD Series storage array receives its power from two power supply modules. In a DC-powered MDSeries storage array, the power supply module receives power from two 48 V DC PSUs. Each powersupply module has two cooling fans.NOTE: The fans that keep the array cool are integrated into the power supply modules and cannotbe replaced separately. If a fan stops functioning, you must replace the entire power supply module.Power indicator codesThe DC power supply module has LEDs that indicate power supply status. Under normal conditions, thepower output and line input LEDs are lit at the same time.20