LIGHTNING, TRANSIENT & HIGH FREQUENCY IMPACT ON MATERIAL SUCH AS CORRUGATED TUBING

In conducting analysis of systems that have failed as a result of lightning and transients, we have observed repeated incidences associated with corrugated flexible tubing. The nature and frequency of lightning strokes is considered. The failure process is investigated. Standards and articles provide adequate minimum design for installation. Ten areas of electrical systems correlate to lightning impact. These are (1) jacket thickness, (2) wall thickness, (3) cathodic cell, (4) high frequency impedance, (5) wire size, (6) number of grounding connections, (7) bonding, (8) voltage levels, (9) damage at high levels, and (10) electromagnetic waveguide. Actual photos illustrate lightning interaction on a charged metal surface, transfer of energy to a pipe system, exit damage on a pipe, and intense arcing on a grounding electrode conductor.