THE INADEQUACY OF EARTHING IN BUILDING STRUCTURES IN ZARIA
THE INADEQUACY OF EARTHING IN BUILDING STRUCTURES IN ZARIA
No Thumbnail Available
Date
2007-10
Authors
MU’AZU, HASSANA ASPITA
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
ABSTRACT
Earthing and lightning protection systems protect people from the danger of electrocution
and equipment from over-voltages by dissipating the excess energy into the earth, and at
the same time reducing the potential difference between equipment and earth. This study
investigated the effect of lightning strikes on people, buildings, communication towers
and equipment by determining the number of lightning strikes on the structures
depending on their location and height as well as the earthing resistances. With the aid of
data obtained from April 1995 to February 2003, from the National Aeronautic and Space
Agency (NASA), Lightning Imaging Sensor (LIS) Science Team and from NASA's
Optical Transient Detector and colour coded onto a map, the annual flash rate for Zaria
was obtained. Based on this, the number of lightning strikes on two structures; the control
tower of the Zaria Aerodrome and the communication tower of the Zaria Nitel Exchange;
were determined. The Fall-of-Potential Method (also referred to as Earth-Spike Method)
was method used for the earth resistance measurement. The null-balance analogue type
Megger Earth Tester was used as the test instrument to determine the earth resistance of
the following locations within Zaria: Department of Electrical Engineering, Zaria
Aerodrome Control Tower, Commercial Complex, No. 8 Sokoto Road and Nitel
Exchange Communication Tower. The earth resistance measurements taken for the
various locations were in conformity with the general standards: "The resistance to earth
of the earth electrode subsystem should not exceed 10Ω at fixed permanent facilities".
All the earthing resistances measured around the ring earth of the Nitel Communication
Tower were within NITEL recommended resistance of less than 1Ω.
Description
A THESIS SUBMITTED TO THE DEPARTMENT OF ELECTRICAL
ENGINEERING, AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL
FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF A
MASTER OF SCIENCE (M. SC) DEGREE IN ELECTRICAL
ENGINEERING
Keywords
INADEQUACY,, EARTHING,, BUILDING,, STRUCTURES,, ZARIA