Installing An Mx240 Dc Normal Capacity Power Supply - Juniper mx240 Hardware Manual

MX240 3D Universal Edge Router Hardware Guide

Installing an MX240 DC Normal Capacity Power Supply

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WARNING: Before performing DC power 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 off position, and tape the switch handle of the circuit breaker
in the off position.
To install a DC power supply (see
Ensure that the voltage across the DC power source cable leads is 0 V and that there
1.
is no chance that the cable leads might become active during installation.
Attach an ESD grounding strap to your bare wrist and connect the strap to one of the
2.
ESD points on the chassis.
Switch the DC circuit breaker on the DC power supply faceplate to the off (
3.
Using both hands, slide the power supply straight into the chassis until the power
4.
supply is fully seated in the chassis slot. The power supply faceplate should be flush
with any adjacent power supply faceplate or blank installed in the power supply slot.
Tighten the captive screws on the lower edge of the power supply faceplate.
5.
Remove the clear plastic cover protecting the terminal studs on the faceplate.
6.
Remove the nuts and washers from the terminal studs.
7.
Secure each power cable lug to the terminal studs, first with the flat washer, then
8.
with the nut (see Figure 105 on page
(2.8 Nm) of torque to each nut. Do not overtighten the nut. (Use a 7/16-in. [11 mm]
torque-controlled driver or socket wrench.)
a. Secure the positive (+) DC source power cable lug to the
b. Secure the negative (–) DC source power cable lug to the
CAUTION: Ensure that each power cable lug seats flush against the surface
of the terminal block as you are tightening the nuts. Ensure that each nut
is properly threaded onto the terminal stud. The nut should be able to spin
freely with your fingers when it is first placed onto the terminal stud.
Applying installation torque to the nut when improperly threaded may
result in damage to the terminal stud.
CAUTION: The maximum torque rating of the terminal studs on the DC
power supply is 36 lb-in. (4.0 Nm). The terminal studs may be damaged
if excessive torque is applied. Use only a torque-controlled driver or socket
wrench to tighten nuts on the DC power supply terminal studs.
Figure 104 on page 250):
251). Apply between 23 lb-in. (2.6 Nm) and 25 lb-in.
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O ) position.
RTN (return) terminal.
(input) terminal.
–48V