Warning: It is particularly important to provide a properly grounded and shielded environment and to use electrical surge-suppression devices.

Signaling limitations

If your site experiences any of the following problems, consult experts in electrical surge suppression and shielding:

• Improperly installed wires cause radio frequency interference (RFI).
• Damage from lightning strikes occurs when wires exceed recommended distances or pass between buildings.
• Electromagnetic pulses (EMPs) caused by lightning damages unshielded conductors and electronic devices.

Radio frequency interference

To reduce or eliminate radio frequency interference (RFI) from your site wiring, do the following:

• Use twisted-pair cable with a good distribution of grounding conductors.
• If you must exceed the recommended distances, use a high-quality twisted-pair cable with one ground conductor for each data signal when applicable.

Electromagnetic compatibility

If your site is susceptible to problems with electromagnetic compatibility (EMC), particularly from lightning or radio transmitters, seek expert advice.

Some of the problems caused by strong sources of electromagnetic interference (EMI) are:

• Destruction of the signal drivers and receivers in the switch
• Electrical hazards as a result of power surges conducted over the lines into the equipment