Juniper Networks M5 - Manual (Page 130)

Replace Power System Components
Connect DC Power to the Router
Connect DC power to the router by inserting power cables from external DC power sources
into the quick-connect terminals on the faceplate of each power supply. Power and grounding
cables are not supplied with the router. For information about the required cable type, see
“DC Grounding, Connection, and Cable Specifications” on page 46.
The router must be connected to at least two separate external DC power
sources.
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 the power supply faceplate. You must ensure that power connections
maintain the proper polarity. The power source cables might be labeled
(+) and (–) to indicate their polarity.
To connect DC power to the router, follow this procedure (see Figure 39):
1. Verify that there is no power flowing from either external power source, so that the
voltage across the leads of the power cables is 0 V. Ensure that there is no chance that
the cable leads might become active during the procedure.
2. For each power supply, verify that the power switch on the power supply faceplate is in
the OFF (O) position.
3. Connect the grounding cable to a proper earth ground for both external DC power
sources, if it is not already.
4. Verify that a licensed electrician has attached the cable lug provided with the router
to the grounding cable, and that the cable is attached to a grounding point on the
chassis rear.
5. If necessary, strip a short section of the protective cladding from the end of each power
cable so that the metal core can come in direct contact with the quick-connect terminal.
6. Thread the power cables through the hook located on the faceplate to the right of
the quick-connect terminals.
7. Insert the exposed end of each power cable straight into the appropriate quick-connect
terminal:
•
Insert the positive (+) source cable into the return terminal, which is labeled RTN.
•
Insert the negative (–) source cable into the input terminal, which is labeled –48V.
110 M5 and M10 Internet Routers Hardware Guide