support.dell.com Dell PowerVault Storage Systems — Rack Installation Guide 1-23Figure 1-19. Installing a Storage System Retention Bracket4. Attach the storage system retention brackets to the support rails.These brackets will secure the inner end of the storage system after it is placedonto the support rails. See Figure 1-19 for the appropriate bracket to use for aDPE or DAE.To install a bracket, align the tabs on the bracket with the holes in the support rail(see Figure 1-19), then secure the bracket using an M5 Phillips pan-head screw.5. If you are installing a DPE, install two cage-nuts in the front vertical rails.To install the cage-nuts, perform the following steps:a. Determine the proper location of the cage-nut: use a felt-tipped marker ormasking tape to place a mark on the rack’s vertical rail.— If the lower edge of the support rail is located at a 1-U increment onthe vertical rail, as shown in Figure 1-16, place a mark on the vertical rail10-1/4 inches (6-U or 26 cm) above the lower edge of the support rail.— If the lower edge of the support rail is located at a 1/2-U increment onthe vertical rail, as shown in Figure 1-16, place a mark on the vertical rail9-3/8 inches (5-1/2-U or 14 cm) above the lower edge of the support rail.b. Install the cage-nut and cage-nut tool as shown in Figure 1-7.support railretention bracket (DAE only)retention bracket (DPE only)mounting bracket nuts (2)Phillips-head-pan-headM5 screws(2 per rail)DAEDPEM5 Phillipspan-headscrewM5 Phillipspan-headscrewMS flat metalwashers(2 per rail)