Background Generally, transformers are predominantly used in virtually every commercial and residential building, from the service transformer reducing the distribution voltage to a more usable voltage for the building, to step-down transformers serving individual floors, to small transformers for individual apparatus or functions. Typically a transformer is a long-lived device that can be in service for decades. Suppose that a student has got the job of designing the power distribution transformer for a residential and commercial areas. Different scenarios, specifications and require- ments of the design are communicated to him, and both the residential and commercial areas are supplied by Saudi Electric Company (SEC) 13.8 kV substation. Goals: Design-I (a-i) Suppose that the residential supply voltage in your area is 220 V. Estimate the load demand in your usual area of residence for 15 different types of loads (e.g., motors, AC, and appli- ances, etc). You need to tabulate V, 1, and kVA ratings of each selected load. (b-i) Determine the TOTAL residential kVA required. (c-i) Add a contingency factor of 20% to the total load demand. The contingency factor is required for reasonable unplanned load growth and for future planned additional load. (d-i) Search the web (market) and find single phase distribution transformers of different ratings. You need to tabulate transformers of 15 different kVA ratings, their manufacturer and cost in US dollars. You can select reasonable minimum and maximum kVA ratings of the trans- former by analysing the total load demand. (e-i) Finally, propose the suitable distribution transformer (s) (i.e., kVA ratings) based on cost and reliability to meet the load demand including contingency factor and load shedding(i.e, during high demand, some load will be turned off to prevent total interruption of service). Usually 60% of loads in residential areas are air conditioners (AC) and will be selected as the portion of the load to be interrupted