| Author: | Lau, Kim-man |
| Title: | Evaluation of lightning and earthing practice in Hong Kong |
| Degree: | M.Sc. |
| Year: | 2001 |
| Subject: | Lightning -- Protection Hong Kong Polytechnic University -- Dissertations |
| Department: | Multi-disciplinary Studies Department of Building Services Engineering |
| Pages: | 1 v. (various pagings) : ill. ; 30 cm |
| Language: | English |
| Abstract: | The aim of this report is to emphasized the significance of lightning protection, earthing and bonding systems although they are relative small item in a building. A survey is conducted on different types of buildings to observe the local practices and common problems, hence, to suggest possible improvements and to encourage good practices on design, installation, inspection and maintenance to be applied in the future. Increasing utilization of the early streamer emission (ESE) together with coaxial cable of lightning protection design in Hong Kong has been noted. It offers a new concept on lightning protection and provides a more simple, cost effective and flexible system design than conventional design. But the increasing risk of side flash due to reduced number of down conductors in a high rise building should be considered. In addition, the use of a coaxial cable as the down conductor should be avoided because of possible insulation breakdown and side flashing at the top of the cable. Instead, the building reinforced steel bar is recommended. Common problems such as high earth resistance and separate "clean earth" requirement for telecommunication installation of building are discussed, and possible solutions are verified. Significant improvements on earth resistance are observed by using the building foundation pilling as the earth electrode or soil chemical treatment. Equipotential bonding between main earth termination, functional earth termination and lightning earth termination must be maintained to reduce the risk of equipment damage and life hazards. As extensive supplementary bonding is required according to the Codes of Practice. Practical testing is suggested to minimize the supplementary bonding. And the selection of the size of supplementary bonding conductor according to regulation is verified. Since there will not be immediately danger when lightning conductors or bonding conductors are being removed, testing and maintenance on these system are always ignored. Poor practices such as outstanding testing record, insufficient commissioning and lack of routine maintenance are found in most buildings. As a result, protection to occupants and property within these buildings is not ensured. |
| Rights: | All rights reserved |
| Access: | restricted access |
Files in This Item:
| File | Description | Size | Format | |
|---|---|---|---|---|
| b15977833.pdf | For All Users (off-campus access for PolyU Staff & Students only) | 5.14 MB | Adobe PDF | View/Open |
Copyright Undertaking
As a bona fide Library user, I declare that:
- I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
- I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
- I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.
Please use this identifier to cite or link to this item:
https://theses.lib.polyu.edu.hk/handle/200/630