Cisco Systems MGX 8220 Maintaining Safety with Electricity, Grounding

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Cisco MGX 8220 Installation and Configuration
Release 5.0, Part Number 78-6430-03 Rev. D0, November 2003
Chapter
Safety Recommendations
•Wear safety glasses if you are working under any conditions that might be hazardous to your eyes.
•Never attempt to lift an object th at might be too heavy to lift a lone.
•Always power OFF all power supplies and unplug all power cables before opening, installing, or
removing a chassis.
Maintaining Safety with Electricity
Warning Before 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 wh en wo rki ng w i th th e 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 safe ty grou nds) .
•Never work alone when potential hazard o us c on d it io ns exist .
•Never assume the power has been disconnected from a circuit; always check.
•Never perform any action th at creates a potential haza rd or makes the equipmen t unsafe for people.
•Never install equipment that appe ars d ama ged.
Warning For 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 240 VAC in AC systems
and 48 VDC in DC systems.
Grounding
The two 48V DC power feed s mu st be properly grounded on the positive 48V and saf ety g r ou nd pins.
Ensure that the MGX 8220 fr ame and all other frames are atta che d to an i sol ate d 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, and installed as part of
the branch circuit that supplies the unit. The grounding conductor described is a separately derived
system, at the supply transformer or motor generator set.