Lightning conductor
This 1876 Currier & Ives print depicts Franklin's kite experiment in June 1752. It's a fanciful illustration of Franklin's identity of lightning and electricity, from which he invented the lightning conductor. |
Contents |
[edit] Introduction
A lightning conductor (or lightning rod) is a metallic tip typically placed at the highest point of a building. Lightning conductors are most often made from conductive materials, such as copper and aluminium, and come in many different forms including hollow, solid, pointed, rounded, flat or brush shaped. Lightning conductors are also referred to as finials, air terminals or strike termination devices.
In the 1800s, some lighting conductors took on decorative characteristics, frequently topped with glass balls and weather vanes.
[edit] Origin
There are earlier examples of exploratory (or even unintentional) lightning conductors prior to the work of Benjamin Franklin. However, it was Franklin who made the formal connection between lightning and electricity. The Franklin Rod tested his theories as part of his ongoing investigations into the properties of electricity.
For his work with lightning conductors, Franklin explored using an iron pole sharpened to a point. He pursued this theory around the same time he proposed the idea of flying a kite with a key attached during an electrical storm.
[edit] How lightning conductors work
Lightning conductors do not prevent lightning strikes, they simply provide a low-resistance path to earth when strikes occur. In this way, the discharge is transmitted through the conductor instead of through the building so that the latter is protected from electrical and other damage, fire or injury to occupants.
To perform this function, the lightning conductor must be properly grounded. One or more types of conductors, often in the form of metal strips, are used to earth the structure. The conductors are sometimes provided with sharp points. At these points the paths of the electric field are closely concentrated so that ionisation of the air around the points takes place.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Cost-of-living crisis and home improvement plans
Starting on the right footing and top tips for projects.
Delays on construction projects
Types, mitigation and the acceleration of works.
From Chaucer to Fawlty Towers.
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.
New project and cultural district described in detail.
The nature of EPCs, crticism and inaccuracies.
History, issues and redesign.
From waste recycling to energy performance the hierchy.
An introduction to WERCS and WEEE responsibilities
Dealing with 2 million tonnes of waste equipment a year.
Global BACS Market: analytics and optimisation
A BSRIA glance at building automation and control systems.
What it is and how to use it.
Types of insulating plaster by binder and insulant.
Investors in People: CIOB achieves gold
Reflecting a commitment to employees and members.
Scratching beneath the surface; a guide to selection.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.
UK gov apprenticeship funding from April 2024
Brief summary the policy paper updated in March.