// Electric Machinery and Transformers // Irving L kosow // Prentice Hall of India // 2nd editiom // Chapter 13: RATINGS,SELECTION,AND MAINTENANCE OF ELECTRIC MACHINERY // Example 13-1 clear; clc; close; // Clear the work space and console. // Given data // MOTOR(class A insulation ) is operated for 6 hrs T = 125 ; // Temperature in degree celsius recorded by the embedded detectors life_orig = 10 ; // Life in years of the motor (standard) // Calculations delta_T = T - 105 ; // Positive temperature difference between the given // max hottest spot temperature of its insulation and the ambient temperature recorded. // 105 is chosen from table 13-1(class A insulation) R = 2 ^ (delta_T/10); // Life reduction factor Life_calc = life_orig / R ; // Reduced life expectancy of the motor in years // Display the results disp("Example 13-1 Solution : "); printf(" \n Life reduction factor : R = %d \n ",R ); printf(" \n Reduced life expectancy of the motor : Life_calc = %.1f years",Life_calc);