Arc flash
（重定向自Breakopen）
![An electric arc between two nails](/Images/godic/202501/01/Lichtbogen_3000_Volt3918.jpg")
![A controlled arc-flash, produced in a flashtube. Even though the energy level used is fairly low (85 joules), the low-impedance, low-inductance circuit produces a flash of 24,000,000 watts. With an arc temperature of 17,000 K (30,100 °F), the radiation output is centered at 170 nanometers, in the far UV. The intense burst of radiation easily penetrates the shade #10 welding filter which shields the camera.](/Images/godic/202501/01/24_Million_Watt_high_speed_flash_through_welding_lens3919.jpg")
![A 480 volt switchgear and distribution panel, requiring category-4 arc-flash protection.](/Images/godic/202501/01/Electrical_Main_and_distribution_panel_for_480_volt3919.JPG")
An arc flash (also called a flashover), which is distinctly different from the arc blast, is part of an arc fault, a type of electrical explosion or discharge that results from a low-impedance connection through air to ground or another voltage phase in an electrical system.