Juniper MX2010, Hardware Manual

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Installing an MX2010 DC Power Supply Module (-48 V)
Before you install a PSM, be aware of the following:
NOTE: The DC PSM is hot-swappable when a minimum number of PSMs installed and operational.
WARNING: The DC PSMs have no circuit breakers that can physically disconnect DC
line from the router. After DC feeds have been connected to the PDM, the DC voltage
is always present on the power midplane and is distributed to the PSM connectors on
the power midplane.
CAUTION: To maintain proper cooling and prevent thermal shutdown of the operating
PSM, each PSM slot must contain either a PSM or a blank panel. If you remove a PSM,
you must install a replacement PSM or a blank panel shortly after the removal.
NOTE: After powering on a PSM, wait at least 60 seconds before turning it back off.
To install a DC PSM (see Figure 168 on page 376 ):
1. With one PSM installed and operational, install an additional PSM with the power supply switch in the
off (O) or in the on (|) position.
CAUTION: If there is only one PSM installed and operational, the power supply
switch must be placed in the off (O) position.
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. While grasping the handle on the PSM faceplate with one hand, use your other hand to guide the power
supply module into the chassis.
4. Tighten the captive screws on the PSM faceplate.
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