The Diseases Of Electrical Machinery

ELECTRICAL MACHINERY. 4i we may short-circuit the defective coil. While in the above cases the breakdown is not in itself dangerous, even in the case of a motor with a regulating resist- ance in the magnet Circuit, since it will be at once noticed, nevertheless the fault may lead to trouble. A break in the regulating, if it were to occur while the motor was running, would cause the motor either to race or to burn out. A continuous-current motor, the excitation of which is suddenly removed, will either run up to an enormous speed, or else stop and be burnt out, according to the load and the position of the brushes. The Connections of Starters for Shunt Motors. Although it may appear superfluous to speak here about the correct connection of a starting resistance, yet numerous unpleasant experiences of the author’s make it appear necessary to him to say something about this question. The rule for a shunt motor is that the starter must be con- nected so that it lies before the armature, see Fig. 20, while the shunt winding is connected parallel to the --------- --------- armature and the starter. In that case we fulfil the condition that when switch- ing in, the shunt stands under the full pressure, i. e that the magnets are strongly magnetised, while the armature current is weakened by the resistance con- ------wwww* Fig. 20.