Problem 7: Lab 4 What are the main differences between single-unit, three-phase power transformers and three- phase transformer banks? Problem 8: (Lab 4) Consider a three-phase transformer bank connected in a wye-delta configuration. Each winding at the primary of the three-phase transformer bank is made of 5400 turns of wire, while each winding at the secondary is made of 1250 tums of wire. If the line voltage Eves at the primary is equal to 100 kV, determine the line voltage Esec. at the secondary