What are air terminals as they relate to lightning protection? I've never worked with air terminals or even seen them before.

An air terminal is the rod that stands on top of the roof/parapet/equipment/etc.
You might know it as a lightning rod.

See NFPA 780
In a NFPA compliant system you will find many of these at the roof/etc.

[This message has been edited by Ron (edited 04-30-2003).]

Air terminals are the little pokey things that point upwards.

   

http://www.harger.com/catalog2002/2_2_1.pdf



[This message has been edited by Bjarney (edited 04-30-2003).]

Thank you Ron.

Bjarney,
Thats a pretty "graphic" warning sign you've got there, I can just feel the pain, looking at the sign!.

[This message has been edited by Trumpy (edited 05-01-2003).]

Bjarney-

Thank you for graphic and text.

There new air terminals available that have a "mushroom" type head to eliminate the impalement hazard. I didn't see them in the catalog that BJ linked to, but I know that that company has them because the first time I saw them was at their booth at a trade show.
Don

Don,
How about this one? http://www.harger.com/catalog2002/2_2_5.pdf
This is the one I currently spec.

Ron,
The one I was thinking about was a mushroom shape, but that one will also prevent the problem.
Don

I thought the reason a lighting rod comes to a point is becaue it seems to "attract" the lightning bolt better?

If this is true (I don't know), wouldn't this make a blunted rod less effective?

If it doesn't matter....why make the tips so sharp?

At the job I am at now they put Rebar caps (orange plastic mushrooms) on the airterminals during the work day and remove them at night to protect the workers on the roof from the sharp points.

I was under the impression that a lightning rod has a very sharp point on it to help eliminate the splatter when the bolt hits it. I might be wrong though but that is what I was told.

I looked it up on the net. I guess that I was misinformed about the points on the rods.
http://www.abcnews.go.com/sections/science/DailyNews/franklin000515.html