Lightning Arrestors vs Surge Suppressors

[lightningprodude]

Is anyone aware of any Nationally recognized agency or article siting the differences between lighnting arrestors and surge suppressors. I have a client that is convinced that a lightning arrestor is sufficient to eliminate transient damage and I would like to site somethning with some credibility to educate him. Can anyone help?
Respone to mikeadams@lightningpro.com

[hurk27]

here's a good site to read up on lighting:

Lightning-protection Institute

[dereckbc]

NFPA is not going to be of any help as they are concerned with protection of fire and safety, rather than equipment protection.

The main difference between lightning arrestors and surge arrestors is which side of the meter it is connected too. Lightning arrestors are primarily used by POCO's, although you can purchase them. They are usually fairly small units that do not offer much protection because of there size and limitations. The best protection comes from the use of a POCO provided lightning arrestor installed at the transformer, and a class "C" service entrance device built into the service equipment.

Information is hard to come by. It is mostly proprietary from companies like telephone and radio. It is a specialized field requiring a lot of training and education. However you can learn a lot from:
ANSI 62.41
ANSI 62.45
UL-1449 Second Edition
NEMA LS1 1992.

You can also refer to the following keeping in mind thier concern is fire, not operation:
NFPA 780
UL-96A
NEC 280
NEC 285

There are also some books written by various professionals. You can find some of them at the Lightning Protection Institute that Wayne pointed to. They are all base on the compiled information provided by ANSI, NEMA, UL, NEC, NESC, and NFPA.

[ December 02, 2003, 06:14 PM: Message edited by: dereckbc ]

[lightningprodude]

I appreciate the responses, I run a lightning protection company and we do 100% full-time lightning protection, so I am painfully aware of ANSI/IEEE, UL 1449 and so forth. I have been struggling with finding a good publication that sites specific differences in lightning arrestors vs. SPD's- not being an engineer myself, I do not carry as much creed as an E.E. speaking on the same topic, although I can explain the differences, I would like to have some published literature on this specific topic.

[hurk27]

LPD one thing to remember. There is no such thing as a surge protector (TVSS) Or a lighnting arrestors that will give you total protection from a lightning hit. I studied Lightning @ U of gainsville back in 1978-82. and there is nothing short of a fairday cage that will give you total protection, And even then there would be no garantee. the most effective means is a set of air terminals that with the connecting GEC's running down to a ground ring or a grid around a structure with 40' raidals running away from the structure with 10' rods at 20' intervals. The site I posted explains this. Then a TVSS system as a finel last dich effort to lessen any voltage left over that might get into a structure. Yes it seems like alot but you get what you pay for.
A 40 or 50KA hit would just destroy a TVSS system that was hit directly. the object is to direct the strike to earth. TVSS systems are not design to do that. they are design to limit voltage spikes between a set of wires and or earth. Intercepting and routing to ground is always the first step! before even thinking about TVSS in true lightning protection.

[lightningprodude]

I appreciate your opinion, however, if you look at the statistics, damage from lightning is far greater to the electronics inside a building as opposed to structural damage. So in terms of bang for your buck, a full system of surge suppression, sized accordingly and installed properly at the right locations in a facility dramatically reduces damage from external transients such as lightning. We routinely use suppressors with a 80kA per mode surge current rating on the main and a 40kA per mode rating on the sub panels and a private labeled plug strip at the wall outlets and have had enough success to be specified with the FAA, and 200 Counties as the lightning protection consultants. Believe it or not, there are suppressors out there that can withstand direct lightning and are warrantied for 25 years for such an application