These power factor meters have three fixed coils as mentioned above and it has three terminals of R,Y and B with axes and these fixed coils are connected mutually at 120 degrees. These coils intersects on the center line of the instrument. A fixed coil C is located at the center of the three fixed coils. This coil C is connected in series with highacross one of the lines. The coil B is threaded by the spindle. It carries an iron cylinder and the sector shaped iron vanes are fixed on it. Thehas no control springs and it carries a pointer and damping vanes.