What is the capacitor?

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 The Capacitor.         A capacitor is formed when two conductors, usually of aluminium, are separated by an insulator sus as paper ect. For use in motors the strips are rolled together into a compact unit and placed into a sealed metal or plastic container. This may be either cylinderical or rectangular in shape and may be mounted on, in, or away from the motor. Two terminals or leads are provied for connection. The name capacitor is descriptive of the operation of the device. The capacitor acts essentially as a storage units that is,has capacity to store electricity and provides a leading current to the auxiliary or starting winding. All capacitors have this quality and all are electrically the same;they differ only in mechanical construction.     THE OIL-FILLED CAPACITOR                 This capacitor is used mainly in the permanent-split capacitor motor and for the two-value capacitor motor. The capacitor use an oil-impregnated paper as the dielectric and are permanently conne
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Star delta starter

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.This starter is fitted above 5H.P and upto 10H.P. in this starter there is two way switch which connects the 6ends of the motor once in star then in Delta. Like D.O.L.starter it also has overload relay ,no volt coil,current adjuster and "off" switch.
   When we operate the handle down it is started, the ends A2,B2,C2,of the motor become short circuited and A1,B1, C1,get the supply. The motor becomes in star and gets 1/√3times or 58% of the full voltage by which the motor takes 1/3r current of that which the motor takes by starting in delta giving full voltage. It dropping of voltage in the line. By decreasing the current the torque of the motor also decreases to 1/3rd of the torque which it will give by direct star in deta. After taking 75% speed when the handle is done on delta, the ends,C1A2,A1B2,B1C2,are short circuited and each joint gets supply which connects the supply in delta and now since the motor is full speed the back e.m.f.is full. The motor is taking full current thereby giving the full torque.

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