128] QUESTION 2 The daily load of a 500 kVA transformer is as given in Table 1, below: Duration (hours) Load Power factor (kVA XXXXXXXXXX XXXXXXXXXXN/A TABLE 1 You are an engineer responsible for...

128] QUESTION 2 The daily load of a 500 kVA transformer is as given in Table 1, below: Duration (hours) Load Power factor (kVA) 3 450 0.8 14 380 0.75 155 0.86 2 0 N/A TABLE 1 You are an engineer responsible for buying a transformer that will supply this load. Two transformers are presented to you as alternatives for supplying this load. Table 2 gives their respective specifications. TRANSFORMER Full load Copper loss kVA Iron loss Cost A 500 2 kW 3.6 kW R210 000 500 1.78 kW 7.0 kW R185 800 TABLE 2 Do the following: Calculate the ALL-DAY efficiency of each unit. (17) 2.1 Calculate the cost of the losses of each unit, if this load runs for 260 days a year, and the average cost of electricity per kW.h is 56 cents. 2.2 (4) If the interest & depreciation charge on the capital invested (i.e., the Cost) is 14.5%, calculate the cost to your company per year for each transformer. 2.3 (3) Now determine the annual cost of each transformer, taking 2.2 & 2.3 into account 2.4 (2) (1) Based on your findings in 2.4, which transformer would you buy? 2.5 [27]