To ensure that the HyperShelf is operating properly, you need to separately purchase a power cord up to 6 ft. for each PC’s power supply. The power cords included with the Dell Precision 3280 Compact Workstations are 3 ft., which are not long enough for full extension of the HyperShelf. By having the correct PC power supply cable length, it allows you to extend the shelf from the server rack for in-rack serviceability.