1.6 inches = 1.6 inches x 1,000 mils per inch = 1,600 mils 0.25 inch = 0.25 inch x 1,000 mils per inch = 250 mils Area = 1,600 x 250 = 400,000 square mils
Type B MCB: Type B devices are generally suitable for domestic applications. They are designed to trip at fault currents of 3 - 5 times rated current.
Type C MCB: Type C devices are the normal choice for commercial and industrial applications These devices are designed to trip at 5 - 10 times rated current
Type D MCB: The Type D devices have more limited applications, normally in industrial use where high inrush currents may be expected. Type D devices are designed to trip at 10 - 20 times.
The speed regulation of a motor expresses how much its speed varies between no-load and full load. The synchronous motor runs at a constant speed whose magnitude is dependent on supply frequency and the number of poles. Since the speed of the motor is constant hence its speed regulation is zero. Under no-load conditions with normal excitation, armature current Ia drawn by a synchronous motor lags the applied voltage V by a small angle.