How strong an electric current can be? In our domestic appliances, we mostly use up to 10A (amperes), sometimes slightly more. But in a high-power equipment similar to that which is used to construct electrical grids, these electric current strength values can easily reach thousands in magnitude.
Image credit: Photonicinduction (still from YouTube video)
So if 10A is quite enough to boil water in your kettle, you can approximately imagine what a couple of thousand amps can do. And it is quite logical to assume that currents like that need extraordinary equipment to safely relay such power to its proper destination. The list of required components includes special cables, insulators, circuit breakers, and fuses.
All of these components are quite special, and their operation poses certain dangers. Some countries even have regulations limiting possibilities of purchasing such components for handling extremely high electrical currents, unless buyer represents companies or other entities specially trained and authorized to use potentially dangerous equipment.
This video quite impressively illustrates specifics of building an electrical circuit capable of conducting 5000 amps. And also shows an interesting experiment about what happens when a fuse burns out while trying to handle extraordinary amount of electric current.
