Juniper MX2020 Hardware Manual page 493

Copyright © 2015, Juniper Networks, Inc.
excessive torque is applied. Use only a torque-controlled driver or socket
wrench to tighten nuts on the DC power supply terminal studs.
CAUTION: You must ensure that power connections maintain the proper
polarity. The power source cables might be labeled
their polarity. There is no standard color coding for DC power cables. The
color coding used by the external DC power source at your site determines
the color coding for the leads on the power cables that attach to the
terminal studs on each power supply.
NOTE: The DC PDMs in slots
and PDM3/Input1
feed , or feed
A
feed redundancy for the system to balance the power draw. For information
about connecting to DC power sources, see
Electrical Specifications" on page
NOTE: Make sure the amperage switch is set to 60 A or 80 A to match
the DC circuit input feed.
Replace the clear plastic cable restraint cover over the terminal studs on the faceplate.
11.
Route the positive and negative DC power cables through the plastic cable restraint
12.
cover.
Verify that the power cabling is correct, that the cables are not touching, and that they
13.
do not block access to router components or drape where people could trip on them.
Switch on the dedicated customer site circuit breaker.
14.
Verify that the LED on the PDM is lit steadily.
–48V
15.
For each of the DC PDMs, switch the DC circuit breaker to the
16.
NOTE: The circuit breaker may bounce back to the
move the breaker too quickly.
Verify that the –48V LED is lit steadily green.
17.
Turn the power switch to the on (
18.
that are installed.
PDM0/Input0
can be powered by dedicated power feeds derived from
. This configuration provides the commonly deployed
B
179.
) position for the PSMs that are zoned for the PDMs
|
Chapter 25: Replacing Components
and to indicate
(+) (-)
, ,
PDM2/Input0 PDM1/Input1
"MX2020 DC Power Subsystem
position.
ON
OFF position if you
,
A/B
461