Study on Lightning Damage by H.R. Heinicke, Inc.
Lightning is always discharging from the top of chimneys and is also always seeking the fastest way to connect the ground to the sky. When tall structures, such as industrial chimneys and smokestacks are not properly grounded to at least 25 ohms, the potential for lightning to ground the chimney through the structure may be greater than through a lightning rod cable or in the case where there is no lightning protection system at all. In conclusion, lightning strike damage occurs when chimneys are not properly grounded.
Lightning cable maintenance is important because when copper oxidizes or the weather works against it over a period of time, connections may become loose or disconnect. Additionally, anchors may come loose, and the wind can work the cable and cause abrasion and disconnections in the lightning protection system. A major problem in grounding systems is the theft of copper. In cases such as this, according to code, the lightning protection cable may be run inside the chimney column or through a building structure rather than being accessible to pedestrians. Additionally, chimney companies typically use a lightning protection cable to access the chimney, which is another reason why it is a good idea to keep the anchors in good condition.
It is not uncommon for lightning systems to be neglected. In fact, there are many chimneys whose owners have never addressed the lightning issue in regards to their chimney at all. However, when there comes a day when the masonry is soaked with water and there is a large discharge more than has been in the past and more than can reach the ground, explosions occur and large portions of the masonry come crashing down to the ground, destroying property and factory equipment. Neglecting to ground an industrial chimney smokestack is not a good idea for insuring better returns of a company's investments. And having a lightning system installed will reduce your insurance costs.
Examples of Lightning Damage to Smokestacks
Testing your lightning protection system not only requires the testing of all connections, as required by the UL 96A, but also testing the ground. There are two ways to test the ground. One method is more involved than the other. One uses existing ground in the building while the other uses the ground in the field. It is best that both methods should be used together to insure proper connection.
If a chimney is not properly grounded, it should be considered that not only is the chimney at risk, but perhaps also a tank that holds chemicals, the factory's transformers, assembly lines, and the access to the building as well. Therefore, to keep a plant running effectively and efficiently, maintenance staff should always include chimney grounding as part of their regular maintenance projects.
The code used for installing lightning protection systems ironically does not include ground testing. As a matter of fact, one could receive a stamped UL 96A approved system with no ground testing whatsoever. Also, ironically the UL 96A refers to the NFPA 780 which infers that 25 ohms are necessary for one ground rod but denies it in another paragraph as said by some interpretations which can appear as a contradiction. However, the military has code that does require ohm testing to match the situation with the ground. We know how to help you ground your chimney properly; apparently other companies do not, nor do the codes that they may necessarily follow or the towns that approve them.
Scheduling regular stack column inspections is an essential is an essential part of any company that has an industrial chimney. If you are not sure how long it has been since you have received an inspection, you should request all aspects of an inspection to be performed. This ensures not only the safety of the smokestack but also helps to avoid costly future industrial smokestack repairs----such as repairs to rusting rebar on industrial smokestacks and industrial chimneys.
Continental Chimney specializes in the safest and most efficient practices for industrial smokestack repair, demolition, and maintenance. For more information on industrial chimney inspections or to schedule your industrial chimney smokestack maintenance with an industrial chimney contractor today, contact us today for a quote or free binocular inspection.
Donald Perry 01/05/2019 Latest Technology