Typical Question...why so much surge?

....after looking over the proposal, I have a few questions for you. If we take a surge does the surge protector have to be replaced? If we have surge protection on the main panels, why do we need them on the distribution panels? As for the outside pole lights, they run through the distribution panel and if we have a surge protector on that, why would I need them on the light poles?

Thank you,

Tammie, General Manager


Hi Tammie,

All good questions. Let me try to answer your questions as briefly and as quickly as possible:

The Omega Power panel suppression (SPD) comes with a 10 Year Limited Warranty. The manufacture Warranties their products because all or almost all of the lightning transients (surges) that are removed by the SPD do not damage the suppressor. Under properly grounded and installed protection systems, this product will have under a 1% return rate due to lightning damage. The lowest in the industry. Progress Energy claims that their suppression losses have dropped by 95% since they switched to this product in 2002. It takes a direct and high magnitude lightning strike to damage these suppressors and if that happens, you will be glad you had them.

There are several reasons why we suppress all layers in the distribution system. Since 1992, IEEE has recommended three ‘layers’ of suppression on the AC power. There are several reasons for this recommendation:
  • By the time the surge gets to the third ‘layer’ of suppression, all of the high energy from a lightning strike has been clamped with decreasing percentages of the energy removed at each layer.
  • Most close proximity lightning strikes energize the power in a building through what we call the ‘back door’. For example, a lightning strike to a light pole, nearby tree, large display signage, etc... will send energy back to the branch panel or the closest point to the strike. Once it gets to the branch panel, it will damage other loads on that same panel. The problem with ‘main only’ suppression philosophy is the suppressor on the Main Switch will have no chance of stopping equipment damage at the branch panel level when this happens. 80% of all transients in a typical facility DO NOT go through the Main.
  • The most important fundamental is: Suppression installed as close as possible to the equipment to be protected. Branch panels, equipment control cabinets, distribution switchgear, equipment disconnects, etc... are usually the closest connection point that we can effectively install suppression. Branch panels usually provide the most cost effective and best performance level for suppression in every electrical system.
  • Upstream suppression serves to protect down stream suppression, a Warranty requirement for the smaller suppressors in the design.

Light poles act like lightning rods in a storm. The pole creates a natural, high energy streamer launch point (beginnings of a lightning strike) as the electrical fields build just prior to the actual strike. We estimate that in some cases, up to 50% of lightning energy will enter through the exterior light pole ‘back door’. The light pole does not have to be struck directly for high energy to move through the pole during the event. The inexpensive protection we place in each light pole provides the first line of defense to the building electrical system from the lightning rod (outdoor light fixture).

Proper suppression and grounding system design is critical. Most lightning rod contractors will recommend one suppressor on the main and try to sell lightning rods for much more money. This approach has proven time and again to be both inefficient and ineffective when protecting electrical equipment from lightning damage. Many other electrical contractors and specifying engineers will only protect the main in their bid or specifications. It is our opinion that they just do not have enough hands on experience, nor do they have our level of understanding of the electrical dynamics of lightning.

The Seminar LP101 Article at
http://www.omegaps.com/ does a good job of explaining this. Written for Alabama Power and Auburn University, this does a nice job of quickly summarizing the main issues.

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Lightning Strike to Boat

Lightning strike kills man near Lake Charles

02:33 PM CDT on Sunday, September 6, 2009

Associated Press

LAKE CHARLES, La. -- A lightning strike on a fishing boat killed one man and injured another. State wildlife agents say Saturday's strike on Old Black Bayou near Lake Charles killed 44-year-old Joe Landry. He was pronounced dead at the scene. His fishing partner -- Richard Bergeron of Lake Charles-- was treated and released later Saturday from a hospital. Investigators say the two were attempting to pick up anchor and retreat from a small storm when lightning hit.
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Matched Array Suppression Design

It is not that uncommon when mixing suppressors of different technologies that coordination becomes a big issue.  Most manufacturers will not warranty their surge products when used in combination with other surge manufacturers products.  This is not a marketing plot. Read More...
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These are selected excerpts from a letter that was written to a large municipal police department after an onsite inspection. Lightning Protection, Bonding, and Suppression coordination topics are discussed. Read More...
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