Dell PowerEdge M420 Hardware Owner's Manual - Page 266

NOTE: PDU inlet cords for this system may be too thick to fit in the wire guides installed in the rack vertical rails. If this is the case, remove the wire guides by removing the attachment screw securing each guide. Route the PDU inlet cords along the vertical rails, securing them with tie wraps or Velcro strips. Power Supply Blanks If the M1000e enclosure is operated with only three power supplies, power supply blanks must be installed in the three unoccupied power supply bays (4 through 6) to maintain proper cooling airflow in the enclosure. Removing a Power Supply Module NOTE: The power supply modules are hot swappable. Remove and replace only one power supply module at a time in a system that is turned on. 1 Release the power cord retention clip and disconnect the power cord from the power supply module. See Figure 4-1. 266 Installing Enclosure Components