To implement a single-phase transformer (120:240V) at 60Hz for a given power s=2,8kVA with a core of iron, armored type, and cooling by natural convection, several calculations need to be done. Here are the steps to perform the calculations:1. Determine the voltage ratioV2 / V1 = N2 / N1where, V1 = primary voltage = 120VV2 = secondary voltage = 240V2. Calculate the current in the secondary windingIS = s / V2where, s = power = 2.8kVA3. Calculate the current in the primary windingIP = IS / awhere, a = transformation ratio = N1 / N2 = V2 / V1 (for ideal transformer)4. Determine the cross-sectional area of the core.A = s / (B * J)where, B = maximum flux density (tesla), J = current density (A/mm²)5. Calculate the number of turns in the secondary winding.N2 = V2 / 4.44 * f * Φmaxwhere, f = frequency = 60Hz, Φmax = maximum flux6. Determine the size of the wire based on the current densityJ = IS / A'where, A' = cross-sectional area of the wire7. Calculate the number of turns in the primary windingN1 = a * N2where, a = transformation ratio = V2 / V18. Determine the size of the wire based on the current densityJ' = IP / A''where, A'' = cross-sectional area of the wireThe calculations can be performed using these steps to implement a single-phase transformer (120:240V) at 60Hz for a given power s=2,8kVA with a core of iron, armored type, and cooling by natural convection.