Juniper ACX5448-D Hardware Manual page 122

To install a DC PSM (see
1. 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. Wrap and fasten one end of the ESD grounding strap around your bare wrist, and connect the other
end of the strap to the ESD point on the chassis.
3. Using both hands, slide the DC PSM straight into the slot on the rear panel of the chassis until the PSM
is fully seated in the slot. The power supply faceplate must align with any adjacent power supply
faceplate or blank installed in the power supply slot.
4. Remove the clear plastic cover protecting the terminals on the faceplate.
5. Remove the screws from the terminals.
6. Secure each power cable lug to the terminal with the screw (see
5 lb-in. (0.6 Nm) and 6 lb-in. (0.7 Nm) of torque to the screw. Do not overtighten the screw (use a
socket nut driver).
a. Secure the positive (+) DC source power cable lug to the RTN (return) terminal.
b. Secure the negative (–) DC source power cable lug to the –48V (input) terminal.
CAUTION:
7. Replace the clear plastic cover over the terminals on the faceplate.
8. Verify that the power cabling is correct, that the cables do not touch or block access to router
components, and that they do not drape where people could trip over them.
Figure 81 on page 126):
You must ensure that power connections maintain the proper polarity. The
power source cables might be labeled (+) and (–) to indicate 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 PSM.
Ensure that each power cable lug seats flush against the surface of the terminal
block as you are tightening the screws. Ensure that each screw is properly
threaded into the terminal. Applying installation torque to the screw when
improperly threaded can result in damage to the terminal.
Figure 83 on page 126). Apply between
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