Attaching bottom-support rails to a four-post rack

The bottom-support rails support the weight of the switch chassis in the rack or cabinet. To maximize the stability of the rack, you must attach these rails at the lowest possible rack unit (RU).

Before you begin

Before you can install the bottom support rails for the chassis, you must do the following tasks.
  • Verify that a four-post rack or cabinet is installed and secured to the concrete subfloor.
  • If any other devices are stored in the rack or cabinet, verify that they are located below where you plan to install the switch. Also, verify that lighter devices in the same rack are located above where you plan to install this switch.
  • Verify that the bottom-support rails kit is included in the switch accessory kit. Unpack and inspect the chassis shipment for completeness and damage.

About this task

Warning: To prevent bodily injury when you mount or service this unit in a rack, take special precautions to ensure that the system remains stable. The following guidelines are provided to ensure your safety.
  • Mount this unit at the bottom of the rack if it is the only unit in the rack.
  • When you mount this unit in a partially filled rack, load the rack from the bottom to the top with the heaviest component at the bottom of the rack.
  • If the rack is provided with stabilizing devices, install the stabilizers before you mount or service the unit in the rack.

Procedure

  1. Position one of the two adjustable bottom-support rails at the lowest possible RU in the rack or cabinet. Adjust the length of the rail so that it stretches from the outer edges of the front and rear vertical mounting rails. Be sure that there is at least 9 RU of vertical space above the rails to install the chassis.

    You can expand the rail so that its mounting brackets are spaced 24 - 32 inches (61.0 to 81.3 cm).

    Figure 1. Positioning bottom-support rail on the SAN384C-6 chassis
    This graphic shows how to position the bottom-support rails on a rack for the SAN384C-6 chassis.
    • 1. Position two bottom-support rails at the lowest RU on the rack.
    • 2. Allow at least 24.5 inches (62.2 cm) (14 RU) for each chassis.
    Figure 2. Positioning the bottom-support rail on the SAN768C-6 chassis
    This graphic shows how to position the bottom-support rail on the SAN768C-6 chassis.
    • 1. Position two bottom-support rails at the lowest RU on the rack.
    • 2. Allow at least 45.5 inches (115.6 cm) (26 RU) for each chassis.
  2. Use a manual Phillips torque screwdriver to attach the bottom-support rail to the rack. Use 3-4 M6 x 19 mm or 12-24 x 3/4 in. screws for each end of the rail. Use a total of 6 - 8 screws for the rail as shown in Figure 3. Tighten each screw to 40 in. lbs (4.5 N.m) of torque.
    Figure 3. Attaching bottom-support rails to a rack on the SAN384C-6 chassis
    This graphic shows how to attach bottom-support rails to a rack on the SAN384C-6 chassis.
    • 1. Adjustable bottom-support rails (2)
    • 2. M6 x 19 mm (or 12-24 x 3/4 in.) Phillips screws (6 - 8 per rail).
    Figure 4. Attaching bottom-support rails to a rack on the SAN768C-6 chassis
    This graphic shows how to attach bottom-support rails to a rack on the SAN768C-6 chassis.
    • 1. M6 x 19 mm (or 12-24 x 3/4 in.) Phillips screws (8 per rail)
    • 2. Adjustable bottom-support rails (2)
  3. Repeat Steps 1 and 2 to attach the other bottom-support rail to the rack.

    The other rail and bracket need to be flipped 180 degrees and installed to the other side of the rack. Both the left and right sides are identical rails and brackets.

    Make sure that the two bottom-support rails are level with each other. If they are not level, adjust the higher rail down to the level of the lower rail.

    After the bottom-support rails are level and as low as possible, install the chassis in the rack or cabinet.