Juniper SRX5400 Hardware Manual page 192

SRX5400 Services Gateway Hardware Guide
178
A DC-powered Services Gateway is equipped with a DC terminal block that is rated
for the power requirements of a maximally configured Services Gateway. To supply
sufficient power, terminate the DC input wiring on a facility DC source capable of
supplying at least 58 A @ –48 VDC for the system, or at least 32 A @ –48 VDC for
each power supply. We recommend that the 48 VDC facility DC source be equipped
with a circuit breaker rated at 40 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 50 A.
A DC-powered Services Gateway 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 Services Gateway and the supply side of the DC wiring.
The marked input voltage of –48 VDC for a DC-powered Services Gateway 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 Services Gateway is a positive ground system, you must connect the
positive lead to the terminal labeled
–48V , and the earth ground to the chassis grounding points.
DC Power Disconnection Warning
WARNING: Before performing any of the following procedures, ensure that
power is removed from the DC circuit. To ensure that all power is off, locate
the circuit breaker on the panel board that services the DC circuit, switch the
circuit breaker to the
breaker in the
OFF
Waarschuwing Voordat u een van de onderstaande procedures uitvoert,
dient u te controleren of de stroom naar het gelijkstroom circuit uitgeschakeld
, the negative lead to the terminal labeled
RETURN
OFF position, and tape the switch handle of the circuit
position.
Copyright © 2014, Juniper Networks, Inc.