Site Electrical Wiring Guidelines; Distance Limitations For Signaling; Radio Frequency Interference; Electromagnetic Compatibility - Juniper Internet Router M160 Hardware Manual

Site Electrical Wiring Guidelines

When planning the electrical wiring at your site, consider the factors
discussed in the following sections.

Distance Limitations for Signaling

Improperly installed wires can emit radio interference. In addition, the potential
for damage from lightning strikes increases if wires exceed recommended
distances, or if wires pass between buildings. The electromagnetic pulse (EMP)
caused by lightning can damage unshielded conductors and destroy electronic
devices. If your site has previously experienced such problems, you might want
to consult experts in electrical surge suppression and shielding.

Radio Frequency Interference

You can reduce or eliminate the emission of radio frequency interference (RFI) from
your site wiring by using 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, you might want to
seek expert advice. Strong sources of electromagnetic interference (EMI) can
destroy the signal drivers and receivers in the router and conduct power
surges over the lines into the equipment, resulting in an electrical hazard.
It is particularly important to provide a properly grounded and shielded
environment and to use electrical surge-suppression devices.
CAUTION: To comply with intrabuilding lightning/surge requirements, intrabuilding
wiring must be shielded, and the shield for the wiring must be grounded at both
ends.

Router Power Requirements

Table 16 lists the power requirements for various hardware components
when the router is operating under typical voltage conditions. For PIC power
requirements, see the M160 Internet Router PIC Guide.
Power Guidelines, Requirements, and Specifications
Preparing for Router Installation
65