Stray currents, electrical hazards

Stray Electrical Currents and Induced Radio Frequency Currents. For information on stray currents see API 2003 [3j. For information on both hazards see the author s review Sources of Ignition in [157]. Electrostatic Discharge (ESD) Damage to Electronic Equipment. Marine Tankers and Barges (see [5] ISGOTT ). 

Static electricity hazards and nuisances are typified by the generation of large potentials (0.1-100 kV) by small charging currents (0.01-100 pA) flowing in high resistance circuits (10 -10 Q). This in part differentiates static electricity from other electrical phenomena. For example, stray currents in low resistance circuits are typically of the order 1 A for potential differences of the order 1 volt (A-4-1.3). The electric field at any point in relation to a conductor is proportional to its potential, while magnetic field is proportional to... 

The hazards which stray currents present to electric blasting caps can be greatly diminished by isolating all electric power lines from ground except at the power source and providing a separate, common bus, bonded to the frames of all electrical equipment. 

Currents flowing into electrolytic environments (ground, water) from inadequately insulated working electric circuits are called stray currents. From the corrosion point of view, industrial equipment powered by dc currents is the most hazardous source of stray currents for metal underground structures. Alternate stray currents of 50 Hz frequency pose a much smaller hazard. Corrosion losses caused by them are estimated at several percent in relation to the corrosion loss caused by dc stray currents of the same magnitude (Baeckmann et al., 1997). 

Traction stray currents are dynamic in character their intensity and flow direction continuously change, depending on the load of the traction and localization of electric locomotives in relation to the power supply substation. As a consequence, dynamic changes of the potential of underground structures and random periods of their anodic and cathodic polarization occur. This renders determination of the hazard caused by electrolytic corrosion difficult (Szeliga, 1994). 

Electrostatic Current, Stray. See under ELECTRICITY, EXTRANEOUS AND HAZARDS ASSOCIATED WITH IT... 

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