support.dell.com Dell PowerVault Storage Systems — Rack Installation Guide 1-19Installing a DPE or DAE in the RackTo install a DPE or DAE in the rack, perform the following steps:1. Determine where you want to install the support rails.CAUTION: If you are installing more than one DPE storage system,install the support rails so that the first storage system is installed justabove its SPS unit tray) which you mounted in the lowest availableposition in the rack).CAUTION: If you are installing one or more DAE storage systems, installthe support rails so that the first DAE is installed just above anyinstalled DPE/SPS set of units installed in the rack or, if there is no DPE/SPS set of units installed, at the lowest available position in the rack.In the Dell rack, the vertical rails of the rack are marked by small indentations in1-U (1.75-inch) increments.• For a DPE, you must install the support rails so that there are 11.375 inches(6 1/2-U or 29 cm) of vertical space between the lower edges of the DPE’ssupport rails and the component in the rack above the DPE.• For a DAE, you must install the support rails so that there are 6.125 inches(3 1/2-U or 15.6 cm) of vertical space between the lower edges of the DAE’ssupport rails and the component in the rack above the DAE.• As shown in Figure 1-16, the lower edge of the support rails must be alignedat a 1-U or 1/2-U increment on the vertical rails.2. After determining where to install the support rails, mark the location of thelower edge of the support rails on the rack’s vertical rails with a felt-tipped markeror masking tape.