Juniper MX480 Hardware Manual page 257

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. Verify that the power supplies are fully inserted in the chassis.
5. Verify that the source power cables are connected to the appropriate terminal: the positive (+) source
cable to the return terminal (labeled RETURN) and the negative (–) source cable to the input terminal
(labeled -48V).
6. Switch on the dedicated customer site circuit breakers to provide power to the DC power cables.
7. Check the INPUT OK LED is lit steadily green to verify that power is present.
8. If power is not present:
Verify that the fuse is installed correctly and turn on the breaker at the battery distribution fuse board
or fuse bay.
Check the voltage with a meter at the terminals of the power supply for correct voltage level and
polarity.
9. On each of the DC power supplies, switch the DC circuit breaker to the center position before moving
it to the on (—) position.
NOTE: The circuit breaker may bounce back to the off (O) position if you move the breaker
too quickly.
If any of the status LEDs indicates that the power supply is not functioning normally, repeat the
installation and cabling procedures described in
10. Verify that the BREAKER ON LED is lit green steadily.
11. Verify that the PWR OK LED is lit green steadily, indicating the power supply is correctly installed and
functioning normally.
If the power supply is not functioning normally, repeat the installation and cabling procedures described
in "Replacing an MX480 DC Power Supply" on page
"Replacing an MX480 DC Power Supply" on page
396.
260
396.