When you use an appliance or other electrical marvel in your home, you are taking advantage of single phase power. However, a typical industrial electrical motor may use three phase power and it is quite different than standard residential power. If you plan to understand what turns the wheels of industry you should have a fundamental grasp of three phase electric power and here is information to get you started.
Let’s Not Get Too Complicated
In order to completely explain three phase power one would have to talk about electrical generators and explain how current is created. You would need to check out sine wave charts and equations and before long the process could get so complicated that you end up more confused than when you started. This is why we are only going to cover basics.
Comparing Household and Industrial Electricity
If you know anything about electricity, you know that standard house current has two hot wires (about 120 volts each) and one neutral wire (which is grounded). You’ll see three large wires coming into the weather head from the transformer. This gives you 120 volts from hot to neutral and 240 from hot to hot.
In commercial applications large equipment draws a lot of power for many industrial electrical motor applications. If you were to use standard single phase power, it would be terribly inefficient. This is why three phase power is used.
Three Phases of Power
A three phase 208 volt system has three hot wires and one neutral. From phase to phase there is 208 volts and 120 volts from phase to ground. On the other hand, a 480 volt system has three hot wires with 480 volts phase to phase and 277 volts phase to ground.
Why Three Phases?
In order to get better understanding of three phase power, picture three paddle wheels in your mind. Paddle wheel A represents single phase 120 volt power (hot to ground). Wheel B is single phase 240 volt power (phase to phase) and wheel C is three phase 208 volts (ungrounded circuit).
Wheel A gets it power from one boost per cycle. It must turn a full 360 degrees to get another boost. Wheel B has two boosters (180 degrees apart) it gets two boosts per cycle to keep spinning. Wheel C has three boosts (120 degrees apart) so it is boosted three times per cycle. Which is the most efficient operation?
If you are using a powerful industrial electrical motor you will get much better energy efficiency and more power from three phase electricity. This is the reason it is in use today for large applications.
