Juniper SRX550 Hardware Manual page 139

Connecting the SRX550 High Memory Services Gateway to a DC Power Source
Copyright © 2016, Juniper Networks, Inc.
Chapter 17: Providing Power to the SRX550 High Memory Services Gateway
CAUTION: Do not mix AC and DC power supplies within the same services
gateway. Damage to the device might occur.
A 645 W DC power supply with PoE support is available for the SRX550 High Memory
Services Gateway.
WARNING: Before performing the following procedure, 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 off position (
breaker in the off position.
You connect DC power to the device by attaching power cables from the external DC
power sources to the terminals on the power supply faceplate. You must provide the
power cables.
The power supply has two sets of terminals, to accommodate a redundant DC power
feed. If one feed fails, the services gateway draws its power from the other feed. The
terminals for Feed A are labeled
. You do not need to use both feeds; if you only have one DC power source, or if you do
B-
not want to use feed redundancy, you can connect just one feed.
To connect the DC source power cables to the services gateway power supply:
Switch off the dedicated facility circuit breakers. Ensure that the voltage across the
1.
DC power source cable leads is 0 V and that there is no chance that the cable leads
might become active during installation.
Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect
2.
the strap to the ESD point on the back panel of the chassis.
Remove the clear plastic cover protecting the terminals on the power supply faceplate.
3.
Verify that the DC power cables are correctly labeled before making connections to
4.
the power supply. In a typical power distribution scheme where the return is connected
to chassis ground at the battery plant, you can use a multimeter to verify the resistance
of the and DC cables to chassis ground:
–48V RTN
The cable with very large resistance (indicating an open circuit) to chassis ground
will be –48V .
The cable with very low resistance (indicating a closed circuit) to chassis ground
will be .
RTN
O ), and tape the switch handle of the circuit
A+ and A- . The terminals for Feed B are labeled B+ and
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