c. Tighten the screw to 7 in
‑
lb (0.79 N m).
Figure 295: Securing the Ground Wire
5. Connect the other end of the wire to a known reliable earth ground point at your site.
6. Connect the switch to the DC power source. See the instructions in
a 450 W or 550 W DC Power Supply
Connecting DC Power Cables to a 450 W or 550 W DC Power Supply
The DC power connection at your facility must be made by a qualified electrician.
Warning
Always make sure that the DC circuit is de-energized before connecting or disconnecting the
DC power cables on the 450 W or 550 W DC power supply.
Caution
Provide proper connection and strain relief on the DC power cables in accordance with all
local and national electrical codes.
To connect the DC power cables to the 450 W or 550 W DC power supply, follow these steps:
1. Verify that the DC circuit is de-energized.
2. Attach an ESD-preventive wrist strap to your bare wrist and connect the metal end to an
appropriate ground point on the rack.
3. Verify that the ground wire is attached to the power supply.
Connecting the Ground Wire to a 450 W or 550 W DC Power Supply
on page 354.
4. Connect the DC power input cables as follows:
a. On each terminal, loosen the screw enough to allow the spade terminal to slide underneath the
captive square washer (see
b. Slide the spade terminal of the negative wire (–48 V) under the captive square washer on the
negative terminal (labeled –).
Replacing DC Power Supplies
Connecting DC Power Cables to a 450 W or 550 W DC
Power Supply
ExtremeSwitching Hardware Installation Guide 355