Using Incandescent Lamp Failure Levels for Assessment of the Surge Environment

The paper reports a joint investigation of the failure modes and levels of incandescent lamps (“light bulbs”) exposed to surges occurring in low-voltage AC power systems. Tests were performed in one European laboratory and in one U.S. laboratory on typical 100-W bulbs used in the two environments, the North American 120-V systems, and the 230-V European systems. Through complementary tests and high-speed video observation of the flashes, more detailed understanding of the parameters has been obtained. Having determined what it takes to fail a light bulb by a surge, this information can be used to assess the surge environment by noting that frequent bulb failures do not occur, therefore surges above the failure threshold must be infrequent.