other devices through the AC power cable and power source or through the air like transmitted radio waves. The Federal Communications Commission (FCC) publishes specific regulations to limit the amount of EMI and RFI emitted by computing equipment. Each Dell system meets these FCC regulations.
To reduce the possibility of EMI and RFI, follow these guidelines:
Operate the system only with the computer cover installed.
Ensure that all expansion slots are covered either by a
Ensure that the screws on all peripheral cable connectors are securely fastened to their corresponding connectors on the back of the computer.
Always use shielded cables with metal connector shells for attaching peripherals to the computer.
To prevent the possibility of RFI from a computer affecting TV reception, follow these guidelines:
Keep any TV set at least 6 ft away from the computer system.
Use cable TV when possible.
Use a directional outdoor TV antenna.
Attach line filters to the TV set.
Use
If interference occurs, rotate the computer or the TV set 90 degrees.
Magnetism
Because they store data magnetically, diskettes and
Monitors
TV sets
Printers
Telephones with real bells
Fluorescent lights
Shock and Vibration
Excessive shock can damage the function, external appearance, and physical structure of a system. Each Dell system has been designed to operate properly after withstanding a minimum of six consecutively executed shock pulses in the positive and negative x, y, and z axes. Each shock pulse can measure up to 50 gravities (G)
Excessive vibration can cause the same problems as mentioned earlier for shock, as well as cause components to become loose in their sockets or connectors. Systems can be subject to significant vibration when being transported by vehicle or when operated in an environment with machinery that causes vibration.
Each Dell system, when operating, is designed to withstand 0.25 G
Power Source Interruptions
Computer systems are especially sensitive to variations in voltage supplied by the AC power source. Overvoltage, undervoltage, and transients (or spikes) can erase data from memory or even cause components to fail. To protect against these types of problems, power cables should always be properly grounded and one or both of the following methods should be used:
Use one of the power protection devices described in the following section, "Power Protection Devices".
Place the system on a dedicated power circuit (rather than having it share a circuit with other heavy electrical equipment). In general, do not allow the system to share a circuit with any of the following:
- Kitchen appliances