Mx104 Dc Power Electrical Safety Guidelines - Juniper MX104 Hardware Manual

MX104 DC Power Electrical Safety Guidelines

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Copyright © 2017, Juniper Networks, Inc.
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 the rating specified in
"MX104 DC Power Specifications" on page 99
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 percent 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 24, –60, or –48 VDC. Use
appropriate gauge wire as specified in
on page 100.
Be sure to connect the ground wire or conduit to a solid office (earth) ground. We
recommend a closed loop ring 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.
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.
The marked input voltage for a DC-powered router is the nominal voltage associated
with the battery circuit, and any higher voltages are only to be associated with float
voltages for the charging function.
Because the router is a positive ground system, you must connect the positive lead to
the terminal labeled + , the negative lead to the terminal labeled
to the chassis grounding points.
DC Power Electrical Safety Warnings for Juniper Networks Devices on page 248
Chapter 35: Electrical Safety Guidelines and Warnings
per input for each power supply.
"MX104 DC Power Cable and Lug Specifications"
– , and the earth ground
247