Calix 500 Series, Руководство пользователя

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Proprietary Information: Not for use or disclosure except by written agreement with Calix.
© 2001-2007 Calix. All Rights Reserved.
Introduction
This document details the National Electrical Code (NEC) requirements for properly
grounding an ONT during installation.
This document also provides specific information for installing the ground on the Calix 500-
Series or 700-Series ONTs, on the following models:
ONT Type Models Available
500-Series 410, 412, 422, 424, 502, 504, 522, 524, 560
700-Series 710, 711, 712, 714, 720, 721, 722, 724, 740, 761
Grounding Purpose
Providing proper grounding to the ONT has two different purposes:
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Grounding provides for the safety of the intended user and maintenance personnel. The
grounding requirements of the NEC provide a degree of safety in the event the outer
metallic case of the protected device becomes energized by a current-carrying conductor.
In this event, the grounded case would cause the over-current device to trip, thereby
removing the power to the device.
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The protection and survivability of the electronics equipment. High voltage spikes that
occur during electrical storms, as well as static buildup on power utility lines, have been
known to cause a great deal of damage to electronic equipment. When the voltage
potentials reach sufficient amplitude, flashovers take place. In most cases, damage is
caused by the super heating present during the flashover. The high voltage potentials that
are induced into AC utility conductors and communications cables during electrical
storms are of a wavelength that approaches the RF spectrum. To be effective in the
discharging of induced RF energy, grounding conductors must provide a low impedance
path to earth. Keeping conductors as short as possible and using the most direct path,
free of sharp bends, will help to lower the impedance of the ground circuit.
Note: Grounding conductors must never be placed inside a metallic conduit unless bonded
at both ends of the conduit so that the conduit itself becomes the conductor.