If the wires exceed the recommended distances, or if wires pass between buildings, give special consideration
to the effect of a lightning strike in your vicinity. The electromagnetic pulse that is caused by lightning or
other high-energy phenomena can easily couple enough energy into unshielded conductors to destroy electronic
switches. You will want to consult experts in electrical surge suppression and shielding if you had similar
problems in the past.
Caution
Shock and Vibration Requirements
The switch has been shock- and vibration-tested for operating ranges, handling, and earthquake standards.
Grounding Requirements
The switch is sensitive to variations in voltage that is supplied by the power sources. Overvoltage, undervoltage,
and transients (or spikes) can erase data from memory or cause components to fail. To protect against these
types of problems, ensure that there is an earth-ground connection for the switch. You can connect the grounding
pad on the switch either directly to the earth-ground connection or to a fully bonded and grounded rack.
When you properly install the chassis in a grounded rack, the switch is grounded because it has a metal-to-metal
connection to the rack. Alternatively, you can ground the chassis by using a customer-supplied grounding
cable that meets your local and national installation requirements. For U.S. installations, we recommend
6-AWG wire. Connect your grounding cable to the chassis with a grounding lug (provided in the switch
accessory kit) and to the facility ground.
You automatically ground AC power supplies when you connect them to AC power sources. For DC power
supplies, you must connect a grounding wire when wiring the power supply to the DC power source.
Note
An electrical conducting path shall exist between the product chassis and the metal surface of the enclosure
or rack in which it is mounted or to a grounding conductor. Electrical continuity shall be provided by using
thread-forming type mounting screws that remove any paint or non-conductive coatings and establish a
metal-to-metal contact. Any paint or other non-conductive coatings shall be removed on the surfaces between
the mounting hardware and the enclosure or rack. The surfaces shall be cleaned and an antioxidant applied
before installation.
Note
Planning for Power Requirements
The switch includes two power supplies (1-to-1 redundancy with current sharing) in one of the following
combinations:
• Two 500-W AC power supplies
• Two 1200-W HVAC/HVDC power supplies
Cisco Nexus 93108TC-FX ACI Mode Hardware Installation Guide
7
Preparing the Site
Shock and Vibration Requirements