Juniper MX240 Hardware Manual page 62

Figure 19: Typical DC Source Cabling to the Router
The DC power supply in PEM0 must be powered by a dedicated power feed derived from feed A, and the
DC power supply in PEM2 must be powered by a dedicated power feed derived from feed B. This
configuration provides the commonly deployed A/B feed redundancy for the system.
CAUTION:
The power source cables might be labeled (+) and (–) to indicate 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.
WARNING:
CAUTION:
drape where people could trip on them.
SEE ALSO
Connecting Power to a DC-Powered MX240 Router with Normal-Capacity Power Supplies | 248
Replacing an MX240 DC Power Supply Cable | 393
General Electrical Safety Guidelines and Electrical Codes for MX240 Routers
Site Electrical Wiring Guidelines for MX Series Routers | 509
You must ensure that power connections maintain the proper polarity.
For field-wiring connections, use copper conductors only.
Power cords and cables must not block access to device components or
64