The centrifugal switch is used to disconnect the starting winding of the motor once the motor approaches its normal operating speed i.e 50% – 70% speed.
The average value of the sine wave over one complete cycle is actually zero. Hence, for a sine wave, the average value is defined over half the period. The average value expressed in terms of peak value is given by Average value = 0.637 × peak value
By the term, torque is meant the turning or twisting moment of a force about an axis. It is measured by the product of the force and the radius at which this force acts. Consider a pulley of radius r meter acted upon by a circumferential force of F Newton which causes it to rotate at N r.p.m. The angular speed of the pulley is ω = 2πN/60 rad/sec Work is done by this force in one revolution = Force × distance = F × 2πR Joule The power developed = Work Done/Time = (F × 2πR)/60/N = (F × R) × (2πN)/60 The power developed = T × ω watt or P = T ω Watt pmech = (ωT)
The total number of the conductor in stranded cable is given by N = 3x2 − 3x + 1 Where x = no. of layer For layer 1 N1 = 3(1)2 − 3(1) + 1 N1 = 1 For layer 2 N2 = 3(2)2 − 3(2) + 1 N2 = 7 In layer 2 no. of conductor = N2 − N1 = 7 − 1 = 6 For layer 3 N3 = 3(3)2 − 3(3) + 1 N3 = 19 In layer 3 no. of conductor = N3 − N2 = 19 − 7 = 12
EXAMIANS
