Juniper Networks EX4200 - Manual (Page 110)

WARNING: It is particularly important to provide a properly grounded and shielded
environment and to use electrical surge-suppression devices.
Table 25: Site Electrical Wiring Guidelines
Guidelines Site Wiring Factor
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.
Signaling limitations
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.
Radio frequency interference
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
Electromagnetic compatibility
Related Topics ■ General Safety Guidelines and Warnings for EX Series Switches on page 207
■ General Electrical Safety Guidelines and Warnings for EX Series Switches on
page 235
■ Prevention of Electrostatic Discharge Damage on EX Series Switches on page 236
■ Power Supply in EX2200 Switches
■ Power Supply in EX3200 and EX4200 Switches on page 26
■ AC Power Supply in an EX8200 Switch
■ DC Power Supply in an EX8200 Switch
84 ■ Site Electrical Wiring Guidelines for EX Series Switches
Complete Hardware Guide for EX3200 and EX4200 Ethernet Switches