Juniper MX2020 Hardware Manual page 406

WARNING:
To ensure that all power is off, locate the circuit breaker on the panel board that
services the AC circuit, switch the circuit breaker to the off position, and tape the
switch handle of the circuit breaker in the off position.
CAUTION:
power supply unit, each PDM slot must contain either a PDM or a blank panel. If you
remove a PDM, you must install a replacement PDM or a blank panel shortly after the
removal.
CAUTION:
before connecting the input power cables. If the PDM must be removed, all input
power cables must be removed from the PDM before the PDM can be removed from
the chassis.
NOTE: After powering off a PDM, wait at least 60 seconds before turning the circuit breaker
back on.
The seven-feed single-phase AC PDM weighs approximately 8 lbs (3.6 kg). The nine-feed single-phase AC
PDM weighs approximately 9 lbs (4.1 kg). To install a single-phase AC PDM:
1. Make sure that the voltage across the AC power source cord is 0 V and that there is no chance that
the cord might become active during the installation process.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to
one of the ESD points on the chassis.
3. (Optional) If you are switching from a DC PDM to an AC PDM, see
Between AC and DC Power" on page 433
bar of the power distribution unit (PDU) cage to AC.
4. Remove the faceplate covering the PDM slot.
5. On the PDM, remove the two thumb screws holding the two ejector levers in the locked position. Put
the screws aside for later use.
Before performing AC power procedures, disconnect all power sources.
To maintain proper cooling and prevent thermal shutdown of the operating
The single-phase AC PDM must be installed and secured in the chassis
for instructions on how to change the setting on the internal
"Converting an MX2000 Router
386