NIRAS VOLUME 5 [5.1] 91
Utilization equipment Equipment which converts electric energy to mechanical work, chemical energy, heat, or light, or performs similar conversions. VAR The term commonly used for voltamperes reactive. Volt The practical unit of electromotive force, or potential difference. One volt will cause 1 A to flow when impressed across a 1-立 resistance. Voltage A unit of electromotive force. One volt applied to a conductor offering 1 立 of resistance will produce a current in that conductor of 1 A. Voltampere Voltamperes are the product of volts and the total current which flows because of the voltage. In dc circuits and ac circuits with unity power factor, the voltamperes and the watts are equal. In ac circuits at other than unity power factor, the voltamperes equal the square root of (watts squared plus reactive voltamperes squared). Watt The practical unit of active power which is defined as the rate at which energy is delivered to a circuit. It is the power expended when a current of 1 A flows through a resistance of 1 立. Pw = I2R Watthour The unit volume of electric energy which is expended in 1 h when the power is 1 W. Wound-rotor induction motor An induction motor in which the secondary circuit consists of a polyphase winding or coils whose terminals are either short-circuited or connected to an external circuit.