When voltage changes occur in rapid succession, with magnitudes large enough to cause lighting level variations. The human eye-brain response is most sensitive to periodic r.m.s. voltage changes that occur at around 8 - 10 cycles per second.
A coil having large number of turns of fine wire is wound on the middle limb of the shunt magnet. This coil is known as pressure or voltage coil and is connected across the supply mains. The voltage coil produces a high ratio of inductance to resistance.
Covered Conductor is extensively used in voltage up gradation projects ranging between 6.6KV to 33 KV. Covered Conductors are longitudinally water blocked and covered with special grades of materials that provide insulation and ultraviolet protection.
1.6 inches = 1.6 inches x 1,000 mils per inch = 1,600 mils 0.25 inch = 0.25 inch x 1,000 mils per inch = 250 mils Area = 1,600 x 250 = 400,000 square mils