T1600 Dc Power Electrical Safety Guidelines - Juniper T1600 Hardware Manual

T1600 DC Power Electrical Safety Guidelines

Related
Documentation
Copyright © 2010, 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 at least 67 A @ –48 VDC
per input for the three-input 240-A power supply or 48 A @ –48 VDC per input for the
four-input 240-A power supply. We recommend that the 48 VDC facility DC source
be equipped with a circuit breaker rated at 80 A (–48 VDC)minimum for the three-input
240-A power supply or 60 A (–48 VDC) minimum for the four-input 240-A power
supply, 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 80 A for a three-input 240-A power supply or 60 A for a
four-input 240-A power supply.
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 of –48 VDC 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
RTN
ground to the chassis grounding points.
Site Electrical Wiring Guidelines for M Series and T Series Routers on page 363
T1600 General Electrical Safety Guidelines on page 330
Appendix A: T1600 Router Safety and Regulatory Compliance Information
, the negative lead to the terminal labeled , and the earth
–48V
335