Installation Guide

c. Slide the spade terminal of the positive wire (–48 V RTN) under the captive square washer on the
positive terminal (labeled RTN).
d. Tighten both screws on the terminal block to 11 in‑lb (1.25 N m).
Figure 270: Tightening Terminal Screws (Connecting to a –48 V Source)
5. Slide the cover into place over the terminal block.
6. Connect the cables to the DC source voltage, using hardware appropriate to the installation site and
following local and national electrical codes.
7. Energize the DC circuit.
Leave the ESD strap permanently connected to the rack, so that the strap is always available when you
need to handle ESD-sensitive components.
You can now connect network interface cables to the switch, using the instructions in Connecting
Network Interface Cables on page 359.
Install a 450 W or 550 W Internal DC Power Supply
Summit 550 W power supply units (PSUs) are available with either front-to-back or back-to-front
airflow. If you install two PSUs, both must have the same airflow direction.
Summit 450 W power supplies are compatible with Summit X480 series switches and with Summit
X670 series switches that have front-to-back ventilation airflow.
Summit 550 W power supplies are compatible with Summit X670 and X770 series switches. They are
available in versions for switches with either front-to-back or back-to-front airflow.
Note
You cannot combine power supplies of dierent wattages in the same switch.
To install a Summit 450 W or 550 W DC power supply, refer to the following sections as needed:
1. Make sure you have the tools and materials you need.
See Required Tools and Materials for Installing a 450 W or 550 W DC Power Supply on page 340.
Installing Switches
Install a 450 W or 550 W Internal DC Power Supply
Summit Family Hardware Installation Guide 339