Juniper SRX5400 Hardware Manual page 235

CAUTION:
the services gateway is operational. For proper airflow, the power supply must remain
in the chassis, or a blank panel must be used in an empty slot.
NOTE: After powering off a power supply, wait at least 60 seconds before turning it back on.
To remove a DC power supply (see
1. Switch off the dedicated facility circuit breaker for the power supply being removed. Follow your site's
procedures for ESD.
2. Make sure that the voltage across the DC power source cable leads is 0 V and that there is no chance
that the cables might become active during the removal process.
3. 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.
4. Switch the circuit breaker on the power supply faceplate to the off position O.
5. Remove the clear plastic cover protecting the terminal studs on the faceplate.
6. Remove the nuts and washers from the terminal studs. (Use a 3/8-in. nut driver or socket wrench.)
7. Remove the cable lugs from the terminal studs.
8. Loosen the captive screws on the bottom edge of the power supply faceplate.
9. Carefully move the power cables out of the way.
10. Pull the power supply straight out of the chassis.
Do not leave a power supply slot empty for more than 30 minutes while
Figure 101 on page 239):
238