|
Work item:
|
K.101 (ex K.sf)
|
|
Subject/title:
|
Shielding factors for lightning protection
|
|
Status:
|
Approved on 2014-12-07 [Issued from previous study period]
|
|
Approval process:
|
AAP
|
|
Type of work item:
|
Recommendation
|
|
Version:
|
New
|
|
Equivalent number:
|
-
|
|
Timing:
|
-
|
|
Liaison:
|
-
|
|
Supporting members:
|
-
|
|
Summary:
|
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.
|
|
Comment:
|
Previously was: Handbook on lightning - New chapter on shielding factors related to lightning
|
|
Reference(s):
|
|
|
Historic references:
|
|
Contact(s):
|
|
| ITU-T A.5 justification(s): |
|
|
|
|
First registration in the WP:
2008-04-07 14:44:52
|
|
Last update:
2015-02-11 10:35:18
|
