February 2012|Online electrical engineering & Electrical Interview Questions

Sunday, February 12, 2012


So here is the Electrical Question and it has been asked by Bagi .His doubt is "What is No Load condition?Can anyone explain what No Load condition exactly mean?" .The answer for this question is very simple.

Let me give an analogy.If you want to carry a lap top or a luggage , it is just a load for you in addition to your weight.Imagine a train (Engine A) running with 2 coaches(Engine A) and another train with 20 coaches(Engine B) .Obviously the Engine A has less load than Engine B to pull.

Similarly when it comes to electrical,we say it as Load current.As the supply voltage is constant, the current consumption will be different for different appliances.If you take a mixer-grinder catalog,there they would have mentioned the rated current for the motor used in it.So whenever there is a appliance running at your home you will be consuming electricity and where does the electricity comes from ? .Can you guess now? .Yes,it comes from the power plant and the appliances we are running at home now act as load for these power plants.

But do our home appliance come in direct contact with the power plants.No is the answer,for supplying the generated electricity we have substations and distribution stations. So the electrical load is in substation as well.Now you will be having clear idea about load.

Whenever we connect/disconnect an appliance to the plug point we ensure that switch is in Off state.If you connect/disconnect keeping the switch in On state,you can see the sparks coming from the plug point.When the appliance is in off state there is no load for the appliance.Same thing applies to isolator in substation.Before doing any maintenance work,the load will be disconnected using circuit breakers.Then the isolators will be opened to perform the maintenance/repair work and closed when the work is over.And then close the circuit breaker to resume the operation.

Now you know why there is announced power cuts in your area.Its for maintenance work or to manage the more demand of electricity.