10Switchmodel Installation methodMinimum distancebetween the frontand rear rack postsMaximum distancebetween the frontand rear rack postsS6820-56HFUsing the mounting brackets andlong slide rails (provided) 692 mm (27.24 in) 854 mm (33.62 in)Using the mounting brackets andsuper-short slide rails (optional,with the chassis rails not reachingout of the chassis)401 mm (15.79 in) 565 mm (22.24 in)Using the mounting brackets andsuper-short slide rails (optional,with chassis rails reaching out ofthe chassis)499 mm (19.65 in) 692 mm (27.24 in)S6820-4C Using the mounting brackets andslide rails (provided) 518 mm (20.40 in) 858 mm (33.78 in)Attaching the mounting brackets and chassis rails to thechassis1. Place the wide flange of the mounting bracket against the chassis side panel. Align themounting bracket installation holes with the screw holes in the chassis. Use M4 screws(provided) to attach the mounting bracket to the chassis.{ To install the mounting brackets at the power module-side mounting position, see Figure13, Figure 14, Figure 15, Figure 16, and Figure 17.{ To install the mounting brackets at the port-side mounting position, see Figure 18, Figure19, Figure 20, Figure 21, and Figure 22.For the S6820-56HF and S6820-4C switches, to install the mounting brackets at the powermodule-side mounting position, use the four screw holes nearest to the power module side. Toinstall the mounting brackets at the network port-side mounting position, use the four screwholes nearest to the network port side.2. Determine the chassis rail installation position:{ If the mounting brackets are installed at the power module-side mounting position, installthe chassis rails near the port side.{ If the mounting brackets are installed at the network port-side mounting position, install thechassis rails near the power module side.3. Place the chassis rail against the chassis side panel. Align the chassis rail installation holes withthe screw holes. Use M4 screws (provided) to attach the chassis rail to the chassis. See Figure13 to Figure 22.You can use super-short slide rails and long chassis rails to rack-mount the S6820-56HF switch.Based on the rack depth, install the long chassis rails not reaching out of the chassis, as shownin Figure 15 and Figure 20 or reaching out of the chassis, as shown in Figure 16 and Figure 21.