Specifications

7-2 Cisco MGX 8220 Reference, Release 4.1
Safety Recommendations
• Never attempt to lift alone an object that might be too heavy.
• Always power OFF all power supplies and unplug all power cables before opening, installing, or
removing a chassis.
Maintaining Safety with Electricity
WarningBefore working on a unit or near power supplies, unplug the power cord(s) on AC units; disconnect
the power at the circuit breaker on DC units.
Follow these basic guidelines when working with the electrical equipment:
• Locate the emergency power-OFF switch for the room you are working before beginning any
procedures requiring access to the interior of the MGX 8220 chassis.
• Disconnect all power and external cables before installing or removing a chassis.
• Examine your work area for possible hazards (for example, moist floors, ungrounded power
extension cables, frayed power cords and missing safety grounds).
• Never work alone when potential hazardous conditions exist.
• Never assume the power has been disconnected from a circuit; always check.
• Never perform any action that creates a potential hazard or makes the equipment unsafe for
people.
• Never install equipment that appears damaged.
WarningFor protection against shock hazard, verify that all power cords are disconnected before servicing
the unit. The maximum voltage that may be present in the unit is 240VAC in AC systems and 48VDC in DC
systems.
Grounding
The two 48VDC power feeds must be properly grounded on the positive 48V and safety ground pins.
Ensure that the MGX 8220 frame and all other frames are attached to an isolated ground connection.
For AC systems, an insulated grounding conductor that is identical in size to the grounded and
ungrounded branch circuit supply conductors, but is green with yellow stripes, is installed as part of
the branch circuit that supplies the unit. The grounding conductor described is to be a separately
derived system, at the supply transformer or motor generator set.