M320 Dc Power Electrical Safety Guidelines - Juniper M320 Hardware Manual

M320 Router Hardware Guide

M320 DC Power Electrical Safety Guidelines

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WARNING: The attached power cable is only for this product. Do not use the
cable for another product.
The following electrical safety guidelines apply to an M320 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 65 A @ –48 VDC
for the system, or at least 48 A @ –48 VDC for each power supply. We recommend
that the 48 VDC facility DC source be equipped with a circuit breaker rated at
60 A (–48 VDC) minimum, or as required by local code. Incorporate an easily accessible
disconnect device into the facility wiring. 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. 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.
Run two wires from the circuit breaker box to a source of 48 VDC. Use appropriate
gauge wire to handle up to 60 A.
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.
Ensure that the polarity of the DC input wiring is correct. Under certain conditions,
connections with reversed polarity might trip the primary circuit breaker or damage
the equipment.
For personal safety, connect the green and yellow wire to safety (earth) ground at both
the router and the supply side of the DC wiring.
Copyright © 2010, Juniper Networks, Inc.