<P> A motor capacitor, such as a start capacitor or run capacitor (including a dual run capacitor) is an electrical capacitor that alters the current to one or more windings of a single phase AC induction motor to create a rotating magnetic field . There are two common types of motor capacitors, run capacitors and start capacitors . The units of capacitance are labeled in microfarads (μF). Older capacitors may be labeled with the obsolete terms "mfd", which means microfarad and "MFD" means millifarad . </P> <P> Motor capacitors are used with air conditioners, hot tub / jacuzzi spa pumps, powered gates, large fans or forced - air heat furnaces for example . A "dual run capacitor" is used in some air conditioner compressor units, to boost both the fan and compressor motors . </P>

Why does an electric motor need a capacitor
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