Wiring and Connecting DC Power
94 7705 SAR-M Chassis Installation Guide
Wiring and Connecting DC Power 
Warnings and Notes 
Danger: 
• Only qualified personnel should install or replace this equipment.
• Confirm that the DC power source is OFF during installation. The power source should 
be a safety extra-low voltage (SELV) source.
• Turn OFF power at the power source before you install or remove power cables or 
cords. 
• The unit should be connected to a DC branch circuit with a 5 A (minimum) and 
10 A (maximum) circuit breaker or fuse that meets the requirements for branch circuit 
protection (applies to both –48 VDC and +24 VDC installations). A suitable disconnect 
device must be provided in the DC branch, either a circuit breaker or switch that can be 
employed to disconnect power to the system during servicing.
• Before working on equipment that is connected to power, remove jewelry, such as rings, 
necklaces, and watches. When metal objects are in contact with power and ground, 
serious burns can occur or the objects can be welded to the terminals.
• You must use cables that meet local electrical code requirements. 
Warning: 
• Do not install equipment that appears to be damaged.
• The router and equipment rack must be properly grounded. Electrostatic discharge 
(ESD) damage can occur if components are mishandled. 
• Always wear an ESD-preventive wrist or ankle strap and always connect an ESD strap 
to a nearby ground point that is connected to the site grounding point when working on 
the 7705 SAR-M. Typical ground points include the ground connection point on the 
7705 SAR-M left-hand side mounting bracket (but only after the 7705 SAR-M is 
installed and the chassis ground wire has been connected), the grounding stud on the 
7705 SAR-M right-hand side mounting bracket, or a properly grounded rack or work 
bench. 
• For IBN installations, the battery return terminal(s) on the 7705 SAR-M must always be 
connected to the building ground at the power source. For redundant supply 
configurations, separate battery return wires must be used.
• For CBN installations, the battery return terminal should be connected to chassis 
ground at the chassis or frame.