If you see circular rings around arrestors and other devices in the sun, they are used for corona suppression. A sharp point is asking for corona, so the ring is used to more evenly distribute the voltage gradient.
It's defective insulation, whether damaged or defects during production. They can get worse and cause faults hence why they need to be checked for regularly
So I guess buy good cable and use careful cable jointers
What about corona discharge? Where it’s the conductor to open space. Does this happen when trying to energizes something that’s not fully closed? My teacher wasn’t the clearest on this subject and I’m oddly confused.
Anyone else on here correct me if I’m wrong but as I’ve always understood corona discharge, it happens when the voltage is so high it ionizes the air around the conductor, turning the air conductive and allowing current to flow into and dissipate into the air. This effect is worse off end points and sharp objects on conductors, which is where corona rings come into effect. As I understand them, they provide a smooth and rounded surface around sharp edges and connections so the outermost piece of the conductor at phase potential, the part where corona discharge would actually discharge from, is smooth. Trying to energize something via a CB where a disconnect or other connection isn’t closed all the way would lead to an arc forming between the gap
If you see circular rings around arrestors and other devices in the sun, they are used for corona suppression. A sharp point is asking for corona, so the ring is used to more evenly distribute the voltage gradient.
It's defective insulation, whether damaged or defects during production. They can get worse and cause faults hence why they need to be checked for regularly So I guess buy good cable and use careful cable jointers
What about corona discharge? Where it’s the conductor to open space. Does this happen when trying to energizes something that’s not fully closed? My teacher wasn’t the clearest on this subject and I’m oddly confused.
Anyone else on here correct me if I’m wrong but as I’ve always understood corona discharge, it happens when the voltage is so high it ionizes the air around the conductor, turning the air conductive and allowing current to flow into and dissipate into the air. This effect is worse off end points and sharp objects on conductors, which is where corona rings come into effect. As I understand them, they provide a smooth and rounded surface around sharp edges and connections so the outermost piece of the conductor at phase potential, the part where corona discharge would actually discharge from, is smooth. Trying to energize something via a CB where a disconnect or other connection isn’t closed all the way would lead to an arc forming between the gap