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| 16 Reactors, Capacitors, Rectifiers.. |

| To describe the functioning of reactors, capacitors, and rectifiersall important types of equipment associated with ac circuitsit is first necessary to understand some of the basic characteristics of ac circuits. Reactors are principally used to limit short-circuit currents, capacitors to reduce current flow and maintain voltage by improving the power factor, and rectifiers to change ac to dc. |

| For inductance, capacitance, and impedance, refer to Chap. 1: Theory of Operation. |

| Reactors |

| Function |

| A reactor is a device used for introducing inductance or inductive reactance into a circuit. Its primary purpose is to limit the current that is allowed to flow through the circuit, particularly under the short-circuit conditions, in order to protect equipment from excessive heat and destructive mechanical forces. It is, therefore, connected in series with the equipment or feeder it is to protect. |

| Principle of Operation |

| A reactor usually consists of a coil wire. The current flowing through the coil produces a magnetic field that cuts the turns of the coil and sets up a counter voltage. With normal current flowing, the counter voltage is relatively |

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