Installing the Mounting Hardware for a Front-Mount Open-Frame Rack
If you are installing the router in a front-mount open-frame rack, you must first install the large mounting shelf on the rack and remove the mounting brackets from the chassis. The small mounting shelf and the spacer bars are not needed.
Table 1 specifies the holes in which you insert screws to install the mounting hardware in an open-frame rack (an X indicates a mounting hole location). The hole distances are relative to one of the standard U divisions on the rack. For reference, the bottom of all mounting shelves is at 0.04 in. (0.02 U) above a U division.
Table 1: Open-Frame Rack Mounting Hole Locations for the M120 Router
Hole | Distance Above U Division | Large Shelf | |
|---|---|---|---|
30 | 17.26 in. (43.8 cm) | 9.86 U | X |
27 | 15.51 in. (39.4 cm) | 8.86 U | X |
24 | 13.76 in. (34.9 cm) | 7.86 U | X |
21 | 12.01 in. (30.5 cm) | 6.86 U | X |
18 | 10.26 in. (26.0 cm) | 5.86 U | X |
15 | 8.51 in. (21.6 cm) | 4.86 U | X |
12 | 6.76 in. (17.1 cm) | 3.86 U | X |
9 | 5.01 in. (12.7 cm) | 2.86 U | X |
6 | 3.26 in. (8.3 cm) | 1.86 U | X |
3 | 1.51 in. (3.8 cm) | 0.86 U | X |
2 | 0.88 in. (2.2 cm) | 0.50 U | X |
1 | 0.25 in. (0.6 cm) | 0.14 U | |
To install the large mounting shelf (see Figure 1):
- On the rear of each rack rail, partially insert a mounting screw into the highest hole specified in Table 1 for the large shelf.
- Install the large shelf on the rack. Hang the shelf over the mounting screws using the keyhole slots located near the top of the large shelf flanges.
- Partially insert screws into the open holes in the ears of the large shelf.
- Tighten all the screws completely.
