page_144

< previous page | page_144 | next page >

Page 144

| Figure 8-14 (a) De-ion arc quencher: 69-kV de-ion breaker. |

| contacts are surrounded by a number of thin metal plates or grids spaced about 1/16 inch or about 2 millimeters apart (Figs. 8-14A and 8-14B). When the contacts open, the resultant arc is broken up into a number of small 1/16-inch arcs, which are then caused by a magnetic field to rotate at very high speeds, thereby preventing overheating and burning of the metal; all arcing is confined to the grid area (Fig. 8-15). |

| In an ac circuit, when the zero point of the current cycle is reached (Fig. |

| Figure 8-15 De-ion arc quenching. |

< previous page | page_144 | next page >