Juniper MX2020 Hardware Manual page 380

Before you remove a three-phase delta AC PDM, be aware of the following:
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.
WARNING:
dangerous voltages.
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.
NOTE: After powering off a PDM, wait at least 60 seconds before turning the circuit breaker
to the ON position.
To remove a three-phase delta 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 removal process.
2. Attach an electrostatic discharge (ESD) grounding strap to your bare wrist, and connect the strap to
an approved site ESD grounding point. See instructions for your site.
3. Disconnect the AC power cord (see
Before performing AC power procedures, disconnect all power sources.
Do not touch the power connectors on the PDM. They can contain
To maintain proper cooling and prevent thermal shutdown of the operating
Figure 163 on page 361) from the power source.
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