3Com 3C16897 8-slot DC Chassis Connecting DC Power To connect DC power cords, do the following

Connecting and Configuring Power 43

Connecting DC Power To connect DC power cords, do the following:

Cords

1Power off all the related parts of the switch when connecting the DC power cord.

2Loosen the mounting screw and remove the cover of the connection terminals on the DC power distribution box.

3Loosen the mounting nut of the connection terminal, using a socket wrench.

4Connect the -48 V terminal (with a blue wire) of the DC power cord on the switch to the terminal marked with -48 V and fasten the nut.

5Connect the grounding terminal (with a black wire) of the DC power cord of the switch to the return terminal and fasten the mounting nut with socket wrench.

6Cover the connection terminals and fasten the mounting screws.

7Connect the other end of the DC power cord to the connection terminal for power input to the switch.

Figure 33 Connecting the DC Power Cord

1	3
2
4

1 -48 V input

2Return

3Grounding screw

4Fastening screw

Configuring AC Power The dual AC input power module uses an internal switch that automatically selects Sources the primary power source. However, to select the primary power source manually,

do the following:

1Connect the first power cord to the AC source or backup system that you select as the primary power source for the chassis.

2Power on the switch. The power module will receive power from the AC source you connected to.

3Connect the second power cord to the second AC source or backup system.

If the primary AC source fails, the switch automatically fails over to the secondary AC source. There is no disruption to system operation during the power fail-over.