Hazard of low-frequency electromagnetic coupling of overhead power transmission lines to electroexplosive devices

The purpose of this investigation was to determine whether the fields generated by overhead transmission lines and stations pose a hazard to electroexplosive devices (EEDs). An analysis showed that under worst-case conditions, the maximum induced current in an EED resulting from power-line coupling is approximately 6.3 mA for the case of electric field coupling and 0.67 mA for the case of magnetic field coupling. The no-fire levels of numerous devices including, but not limited to, impulse cartridges, blasting caps, detonations, flares, switches, and pressure cartridges were compared to determine the most sensitive. It was concluded that worst-case coupling assumed in the analysis is insufficient to induce a hazardous current level in an EED