M7I Dc Power Electrical Safety Guidelines - Juniper M7i Hardware Manual

Related
Documentation

M7i DC Power Electrical Safety Guidelines

Copyright © 2019, Juniper Networks, Inc.
Green and yellow—Earth
Blue—Neutral
Brown—Live
When a router is equipped with two AC power supplies, both power cords (one for
each power supply) must be unplugged to completely disconnect power to the router.
Note the following warnings printed on the AC power supply faceplate:
To completely de-energize the system disconnect maximum of 2 power cordsets.
Apparaten skall anslutas till jordat uttag när den ansluts till ett nätverk. [Swedish]
Preventing Electrostatic Discharge Damage to an M7i Router on page 228
General Electrical Safety Guidelines and Electrical Codes for M Series, MX Series, and
T Series Routers on page 254
M7i DC Power Electrical Safety Guidelines on page 255
The following electrical safety guidelines apply to a DC-powered router:
A DC-powered router is equipped with a DC terminal block that is rated for the power
requirements of a maximally configured router. To supply sufficient power, terminate
the DC input wiring on a facility DC source capable of supplying at least 31 A @ –48 VDC
per input for each power supply.
Incorporate an easily accessible disconnect device into the facility wiring. We
recommend that the 48 VDC facility DC source should be equipped with a circuit
breaker rated at 40 A (–48 VDC) minimum, or as required by local code. In the United
States and Canada, the 48 VDC facility should be equipped with a circuit breaker rated
a minimum of 125% of the power provisioned for the input in accordance with the
National Electrical Code in the US and the Canadian Electrical Code in Canada.
Run two wires from the circuit breaker box to a source of 48 VDC. Use appropriate
gauge wire to handle up to 50 A.
Be sure to connect the ground wire or conduit to a solid office (earth) ground. A closed
loop ring is recommended for terminating the ground conductor at the ground stud.
A DC-powered router that is equipped with a DC terminal block is intended only for
installation in a restricted access location. In the United States, a restricted access
area is one in accordance with Articles 110-16, 110-17, and 110-18 of the National Electrical
Code ANSI/NFPA 70.
NOTE: Primary overcurrent protection is provided by the building circuit
breaker. This breaker should protect against excess currents, short circuits,
and earth faults in accordance with NEC ANSI/NFPA70.
Chapter 38: Electrical Safety Guidelines and Warnings
255