But, that doesnât mean students have to take them all in the same week. Our class structure allows us to provide 5 cycles of classes for every 30-day period. As long as students take the classes in order, (Class 1, Class 2, Class 3, Class 4), they are free to switch between any of the cycles for that 30-day period. The only other requirement is that all 4 classes must be completed within 30 days of the first class.
Re: Advantages of three phase systems over single phase. The big advantage with 3 phase mains is that any electric motor connected to it is more efficient, has smother running and uses less parts so is more reliable. There is also a slight advantage in using 3 phase transformers over single phase ones.
In electrical engineering, three-phase electric power systems have at least three conductors carrying alternating current voltages that are offset in time by one-third of the period. A three-phase system may be arranged in delta or star. A wye system allows the use of two different voltages from all three phases, such as a 230/400 V system which provides 230 V between the neutral and any one of the phases, and 400 V across any two phases. A delta system arrangement only provides one voltage magn