Work item:
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K.101 (ex K.sf)
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Subject/title:
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Shielding factors for lightning protection
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Status:
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Approved on 2014-12-07 [Issued from previous study period]
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Approval process:
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AAP
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Type of work item:
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Recommendation
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Version:
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New
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Equivalent number:
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-
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Timing:
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-
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Liaison:
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-
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Supporting members:
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-
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Summary:
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This Recommendation contains the calculation procedure for the shielding factors used in ITU T K.46, ITU-T K.47, ITU-T K.56, and ITU-T K.94, and it is intended to:
i. provide the rationale for the shielding factor approximate formulas or values contained in the aforementioned Recommendations;
ii. allow a more precise calculation of the shielding factors, by using the equations provided in this Recommendation.
The shielding factors considered in this Recommendation refer to:
" The lightning current distribution in a telecommunication tower, i.e., the tower factor (?T) as per ITU T K.56 and ITU-T K.97.
" The lightning current distribution among several conductors placed in a cable ladder, i.e., the feeder factor (?F) as per ITU T K.56 and ITU-T K.97.
" The shielding factor (?) provided by cable trays, as per ITU T K.56.
" The guard wire shielding factor (?) as per ITU T K.47.
" The refraction factor (?) due to the earthing connection of a telecommunication cable, as per ITU T K.46.
" The shielding factor (?) provided by a telecommunication cable having a metallic sheath (shield), as per ITU T K.46.
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Comment:
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Previously was: Handbook on lightning - New chapter on shielding factors related to lightning
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Reference(s):
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Historic references:
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Contact(s):
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ITU-T A.5 justification(s): |
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First registration in the WP:
2008-04-07 14:44:52
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Last update:
2015-02-11 10:35:18
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