ADEMCO RapidEye plus, Инструкция по установке и настройке

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Rapid Eye Remote Video Unit Installation and Setup Guide
Appendix C: Common CCTV Practices
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C.3.1 Ground Loops and Hum Bars
Electrical equipment is designed so that electronic circuitry is grounded
at one or more points on the equipment chassis. The system must be
designed so that these ground points are electrically connected together
and connected to the chassis or earth ground (green wire).
Ground loops can be detected before connecting the cable. Measure the
voltage difference before connecting the cable and chassis for a system
with a long run, or between any two electrical supplies.
Hum bars appear as horizontal distortion across the monitor. The hum
bar is caused by the effect of high voltage on the horizontal
synchronization signal.
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Caution: Do not attempt to solve any of the above problems
by removing the third wire on a three-prong electrical plug.
This is a violation of local electrical codes, and the
Underwriters Laboratory (UL) recommendations.
C.3.2 Electrical Interference
To eliminate electrical interference (or EMI), conduct a facility site
survey before installing any equipment. Cables can then be routed
around noisy electronics equipment so that there will be no interference
with the TV signal.
Use triaxial or fiber optic cable instead of coaxial cable when the cable
must be routed through an area having EMI caused by large machinery,
high voltage power lines, refrigerator units, microwaves, or other
sources. Triaxial cable has a center conductor, insulator, and shield,
followed by a second insulator and shield. The double shielding
significantly reduces the amount of EMI radiation that is exposed to the
center conductor.