Juniper SRX3400, Hardware Manual, Page: 93 / 232

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Powering Off the SRX3400 Services Gateway on page 82
Connecting the SRX3400 Services Gateway to a DC Power Source
You connect DC power to the services gateway by attaching power cables from the
external DC power sources to the terminal studs on the power supply faceplates. You
must provide the power cables.
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, and tape the switch handle of the circuit breaker
in the off position.
WARNING: To meet safety and electromagnetic interference (EMI)
requirements and to ensure proper operation, you must properly ground the
services gateway chassis before connecting power. See
“Grounding the
SRX3400 Services Gateway” on page 76 for instructions.
CAUTION: Before services gateway installation begins, a licensed electrician
must attach appropriate cable lugs to the grounding and power cables that
you supply. A cable with an incorrectly attached lug can damage the services
gateway.
CAUTION: Do not mix AC and DC power supplies within the same services
gateway. Damage to the services gateway might occur.
To connect the DC source power cables to the services gateway for each power supply:
1.
Switch off the dedicated facility circuit breakers. Ensure that the voltage across the
DC power source cable leads is 0 V and that there is no chance that the cable leads
might become active during installation.
2.
Remove the clear plastic cover protecting the terminal studs on the faceplate.
3.
Verify that the DC power cables are correctly labeled before making connections to
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 that the ohm
output of the
-48V and RTN DC cables to chassis ground. The cable with very large
resistance (indicating an open circuit) to chassis ground will be -48V and the cable
with very low resistance (indicating a closed circuit) to chassis ground will be RTN .
79 Copyright © 2013, Juniper Networks, Inc.
Chapter 8: Grounding and Providing Power to the SRX3400 Services Gateway