page_210

< previous page | page_210 | next page >

Page 210

| Figure 11-11 Link expulsion fuse: (A) 25-ampere fuse before and after blowing, (B) 200-ampere fuses with extra heavy pigtail for carrying large currents, and (C) 75-ampere fuse without fiber tube and spring. (Courtesy, James R. Kearney Corp.) |

| holder are mounted between stationary contacts in open air; such open cut-outs also hinge at the bottom. In both instances, when the fuse blows, some indication is given. In one instance, the door of the cut-out (Fig. 11-12A) or the fuse holder (Fig. 11-12B) is flipped to the open position. In the other, the blown fuse cartridge drops so that it can be seen from the ground (Fig. 11-13 on pages 212-13). |

| A similar fuse is used for some voltage ratings above 15,000 V, usually associated with electric transmission lines (up to about 69 kV), although the fuse element may be different; it may be a liquid, sand, boric acid, or de-ion fuse. |

| Double Venting |

| Unlike the enclosed cut-out where the expulsion tube vents only at one end, usually the bottom, the open cut-out may have an expulsion tube that vents at one or both ends, sometimes referred to as double venting. In the latter case, the tube can vent accumulated gases more rapidly and can have a |

< previous page | page_210 | next page >