Search results
Results from the WOW.Com Content Network
An electric arc between two nails. An electric arc (or arc discharge) is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma, which may produce visible light. An arc discharge is initiated either by thermionic emission or by field ...
An arc flash is the light and heat produced as part of an arc fault (sometimes referred to as an electrical flashover), a type of electrical explosion or discharge that results from a connection through air to ground or another voltage phase in an electrical system. Arc flash is distinctly different from the arc blast, which is the supersonic ...
For air at standard conditions for temperature and pressure (STP), the voltage needed to arc a 1-metre gap is about 3.4 MV. [7] The intensity of the electric field for this gap is therefore 3.4 MV/m. The electric field needed to arc across the minimal-voltage gap is much greater than what is necessary to arc a gap of one metre.
The electric arc occurs between the contact points (electrodes) both during the transition from closed to open (BREAK) and from open to closed (make) when the contact gap is small and the voltage is high enough. Heating due to arcing and high current density can melt the contact surface temporarily.
Every time an electrical power device (for example: heaters, lamps, motors, transformers or similar power loads) turns on or off, its switch, relay or contactor transitions either from a CLOSED to an OPEN state ("BREAK") or from an OPEN to a CLOSED state ("MAKE"), under load, an electrical arc occurs between the two contact points (electrodes) of the switch.
It is a type of welding that uses a welding power supply to create an electric arc between a metal stick ("electrode") and the base material to melt the metals at the point of contact. Arc welding power supplies can deliver either direct (DC) or alternating (AC) current to the work, while consumable or non-consumable electrodes are used.
Along with the similar brush discharge, the corona is often called a "single-electrode discharge", as opposed to a "two-electrode discharge"—an electric arc. [ 1 ] [ 2 ] [ 3 ] A corona forms only when the conductor is widely enough separated from conductors at the opposite potential that an arc cannot jump between them.
Like the related corona discharges and brush discharges, a streamer discharge represents a region around a high voltage conductor where the air has suffered electrical breakdown and become conductive , so electric charge is leaking off the electrode into the air, but the opposite polarity electrode is not close enough to create an electric arc ...