Juniper SRX 5600 Hardware Manual page 93

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.
You connect DC power to the device 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 (the cable lugs are supplied with the device). For power
cable specifications, see "DC Power Cable Specifications" on page 190.
To connect the DC source power cables to the device for each power supply:
Switch off the dedicated facility circuit breakers. Ensure that the voltage across
1.
the DC power source cable leads is 0 V and that there is no chance that the cable
leads might become active during installation.
Switch the circuit breaker on the power supply faceplate to the
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
4.
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
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
CAUTION: You must ensure that power connections maintain the proper polarity.
The power source cables might be labeled
is no standard color coding for DC power cables. The color coding used by the external
DC power source at your site determines the color coding for the leads on the power
cables that attach to the terminal studs on each power supply.
Remove the nuts and washers from the terminal studs. (Use a 3/8-in. nut driver
5.
or socket wrench.)
Secure each power cable lug to the terminal studs, first with the flat washer, then
6.
with the nut (see Figure 36 on page 68). Apply between 23 lb-in. (2.6 Nm) and
25 lb-in. (2.8 Nm) of torque to each nut. .(Use a 3/8-in. nut driver or socket
wrench.)
Chapter 9: Grounding and Providing Power to the Services Gateway
and DC cables to chassis ground. .
48V RTN
.
RTN
(+) and ( ) to indicate their polarity. There
Connecting Power to a DC-Powered Services Gateway
OFF position.
67