What impact does damage caused by lightning strikes have? How can buildings and systems be protected?
Depending on the energy involved, lightning strikes can result in extensive destruction to buildings and systems, which can result in further, secondary damage.
In terms of residential or commercial buildings, which are regularly frequented by people, such damage is immediately noticed. Remedial measures to limit the damage can normally be initiated rapidly. Following such an event, the extent of the damage can be evaluated quickly and precisely. Immediate repair and recommissioning of important system functions can prevent secondary damage.
It is normally not possible for employees to continuously monitor exposed or large-scale systems. Damage or destruction is often only detected once secondary damage has occurred. For this reason, intelligent monitoring systems are increasingly used. These permanently monitor the different function statuses in a system and send the results directly to a central control unit. This enables an immediate response in the event of a malfunction and prevents secondary damage as well as long downtimes.
Up to now, there was no measuring system which could be used to reliably detect and evaluate lightning strikes on a system. Accordingly, there was no damage or fault reporting of such events.
Systems which are exposed and particularly at risk of lighting strike include, for example, wind power plants, power plants, large-scale industrial plants, and railway systems. In such systems, complete lightning protection is generally very difficult to implement, even impossible.
For detection and evaluation of lightning strikes, the LM-S lightning monitoring system is available from Phoenix Contact. It essentially consists of an evaluation unit and a sensor, which is mounted on the down conductor of a lightning protection system.
This measuring system utilizes the Faraday effect or the magneto-optic effect in order to analyze the level and flow direction of lightning surge currents, which occur in lightening arresters. In this process a light wave is magnetically influenced and the influencing value is evaluated as a measuring result. The signal transmission also takes place via fiber optics.
This offers crucial advantages in comparison to signal transmission via copper cable. Lightning currents which occur in the vicinity of the measuring system are unable to influence the light signal or couple into the transmission path. This means that the evaluation unit electronics receive a reliable and, from an EMC perspective, harmless, signal.