Electrical insulators play a substantial function in electrical power distribution. To eradicate the induced voltages in Cable Screen is to bond (Earth) the sheath at both ends of the cable circuit. The resistance involving Phase-Phase-Neutral-Earth should under no circumstances be much less than .5 M Ohms for the usual supply voltages.
The eddy currents circulating radially and longitudinally of cable sheaths are generated on equivalent principles of skin and proximity effects i.e. they are induced by the conductor currents, sheath circulating currents and by currents circulating in close proximity existing carrying conductors.Overhead transmission lines are insulated from their assistance towers by ceramic, phenolic or other materials. Up to 33 kV, pin sort insulators are preferred more than suspension kind insulators simply because they are less costly in price and beyond this voltage, they become uneconomical.Sadly insulator failure is a principal purpose why electrical devices cease operating.
Preventive Upkeep And Checklist need to provide quite higher insulation resistance to the leakage currents. Having said that, for high voltage transmission lines , strain insulator consists of an assembly of suspension insulators as shown in Figure.
An overhead line method with supports, insulators, conductors and accessories comes in the way of scenic beauty and is generally an eyesore to the viewing public. From the line, the current path might be over the insulator down the pole to the ground.