Replacing An M320 Dc Power Supply Cable - Juniper M320 Hardware Manual

M320 Router Hardware Guide

Replacing an M320 DC Power Supply Cable

202
To replace a power cable for a DC power supply:
Locate a replacement power cable that meets the specifications defined in "M320
1.
DC Power Cable Specifications" on page 257.
CAUTION: A licensed electrician must attach a cable lug to the power
cable that you supply. A cable with an incorrectly attached lug can damage
the router (for example, by causing a short circuit).
Make sure that the voltage across the DC power source cable leads is 0 V and that
2.
there is no chance that the cables might become active during the removal process.
CAUTION: You must ensure that power connections maintain the proper
polarity. The power source cables might be labeled
their polarity. There 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.
Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect
3.
the strap to one of the ESD points on the chassis.
Switch the circuit breaker on the DC power supply faceplate to the off position (
4.
Remove the power cable from the DC power source.
5.
Remove the clear plastic cover protecting the terminal studs on the faceplate.
6.
Remove the nuts and washers from the terminal studs (see Figure 107 on page 203).
7.
(Use a 7/16-in. (11 mm) nut driver.)
Remove the cable lug from the terminal studs.
8.
Loosen the captive screw on the cable restraint on the right edge of the power supply
9.
faceplate.
Carefully move the power cable out of the way.
10.
Attach the lug on the replacement power cable to the terminal studs, making sure
11.
the cable is not touching or in the way of any router components.
Attach the lugs on the DC source power cables to the terminal studs.
12.
Attach the lugs on the positive (+) DC source power cables to the terminal studs.
a.
Attach the lugs on the negative (–) DC source power cables to the terminal studs.
b.
Secure each cable lug to the terminal stud, first with a washer, then with a nut. Use a
7/16-in. (11 mm) nut driver or socket wrench to tighten the nut. Apply between 23 lb-in.
(2.6 Nm) and 25 lb-in. (2.8 Nm) of torque to each nut.
and to indicate
(+) (–)
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