EMC System Protection for Contemporary Lightning Protection

EMC System for Contemporary Lightning Protection
by
Daniel Soleil

Abstract : Electromagnetic Compatibility (EMC) is under-emphasized in the typical approach to lightning hazard mitigation to high value facilities. For modern sensitive structures with electrical, electronic or explosives storage, properly constructed EMC architecture is required.

EMC classical domain is a lot of features for equipment as others (density, weight, acoustical noise etc.) : conduction currents and radiation fields. Making sites is today a classical combination of good equipments (not sensitive and not attacker) and fitted as the best art rules known and standards up to date. The lightning protection driven by CEI 62 305 is a typical authoritarian step to secure large systems.

The researches about “zero failure” from the elecromagnetical environment show many mistakes with these classical rules. A better analysis called EMC System is born from military, aeronautic, spatial activities with stimulations of circuits with continue and transient waves to measure and calculate coupling and attenuation. These works are very complex and employed heavy measurements and calculations by strong electromagnetical specialists.

A new approach called Zero method is recognized from more 15 years ago, based only on the measurement of electrical noises in place inside of large sensitive installations. It seems some axis of researches and don’t need stimulations. It is very performing and appreciated by industrials customers for hospitals, petroleum, gas and power plants, computers, robotized factories etc.

Zero method is a performing and economic tool to treat electrical disturbances and lightning protection for the target “zero failure”.

What about zero method ? (See some papers USA, Russian, UK, Paris, Singapour)

Zero method rests only on an obvious fact : Reference potentials must never be disturbed. Generally the 6 references are : Electronic zero, DC and AC energy, ground, earth and communications.

Then it revisits Ohm generalized law : v = zi = 0 with only i = 0. That is the good manner to obtain the famous equipotentiality with HF currents. We note z = 0 is only good for the personal and goods safety in LF domain. For that, zero method rests on 2 specialized measurements : v = 0 and I = 0.

Now it is possible to correct the sensitive installations by these specialized working

• Hardening sources of energy and distributions
• Derivating out of the sensitive meshed grounding network to a specialized lightning earthing.
• Using new specialized EMC System rules for topology and fitting (grounding the shielding wires, electromagnetic plates etc.)
• Using some specialized EMC System components inside of classical circuits energy or signals.

Conclusions :

EMC System is able to resolve the electrical effects coming from the industrial disturbances and the lightning effects inside of large sensitive installations.

It is an interesting tool to help the analysis of a site by CEI 62 305 which gives the different solutions for before and after lightning protection level.

Lastly, it is a particularly appreciated method for electricians in charge to resolve these delicate problems of disturbances. The efficiency of these solutions is confirmed along more 15 years of operation.

It is particularly quick and economical, some customers calculate at less 2 years the feed back of money for lightning protection, out of the stand by of exploitation.

This document is available in PDF format by clicking our Documents Button on top of page and following instructions.