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Show When tho Fuse Blows. The "blowing" of a fuse In an electric street car. which fills tho average passenger pas-senger with alarm, simply Indicates that a safety device bus proved reliable and thai a danger of Injury to thc motor has been averted by It. Thc current which will flow through a motor- when It Ih standing j-tlll Is In almost all Gases far in excess of that which tho motor Is designated desig-nated to carry: nnd indned in a well designed de-signed motT a current dangerous for the motor svl'd Lo reached before tho motor has been staficd. The effect of this "heavy current on thc motor. If allowed to uon-tlnue. uon-tlnue. Is to heat thc windings to a dangerous dan-gerous degree and destroy the Insulation, possibly setting it on fire; and it is to prevent this occurrence, whether due to careless handling of the car or to unexpected unex-pected causes, that tho fuses are used. A fuse Is simply a short piece of wire of Huch a size that It will be melted by a current cur-rent which, If allowed to How through the motor tor any time, will damage It. Thc melting of the fuse opens the circuit and cuts ofT the current from tho motor. To protect thc car thc fuse Is pjaced In a fireproof box. When the Use- Plows out there Is generally gen-erally a volatilization of the metal of the fuse and a slight explosion These explosions explo-sions usually cause a report and some smoke. Chicago Tribune. ' |