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.
We mentioned above that, in Canada, the voltage between the active and neutral in the single phase, low voltage supply to our homes is 120 volts and that this phase is only one of the phases in the 3 phase system. The voltage between the phases of a 120/208V 3 phase system is 208 volts (in Canada). A 208 volt, 3 phase supply is able to deliver more energy than a 120 volt, single phase supply. 3 phase supplies are normally restricted to large electrical loads, such as large electric motors.