Phoenix Contact LM-S lightning monitoring system

The LM-S lightning monitoring system analyses lightning surge current characteristics. The analysis can be used to evaluate industrial system loads more effectively than using the number of lightning strikes and the maximum surge current amplitude, Phoenix Contact claims. Additional parameters such as surge current slope, charge and specific energy allow inferences to be made as to the actual operational system load.

The analysis unit uses up to three optical sensors mounted directly on the arresters through which the lightning surge current passes. The sensor connects to the electronic analysis unit via a fibre-optic cable, separating the electronic system from the lightning surge currents being measured. This prevents interference and damage to the electronic system.

The unit’s electro-optical converters emit light signals for measurement and convert them into electric signals after they pass through the sensor. A processor with a data buffer continuously analyses the signals. When a lightning event occurs, the characteristic parameters for the surge current are calculated from these values.

The lightning surge current amplitude, maximum current slope, charge and specific energy of the lightning strike are stored in the analysis unit and accessed via an ethernet interface. The LM-S can thus be integrated into the existing infrastructure.

The web interface can be used to make calibrations and adjustments for local conditions. In order to calculate the parameters, the unit’s web interface provides a selection of profiles. Up to 500 data records can be stored in the analysis unit memory. This data can be transmitted to external computers using the export function for statistical analysis and archiving.