When you buy a new appliance, you would have noticed that they tell you what the power rating is? Are you a bit baffled by this? It’s not surprising considering that not all appliances use the same electricity connection power units.
They might be displayed in kilowatts (kW) or kilovolt-amperes (kVA.) You might think it is the same thing, but, depending on the type of circuit, it usually isn’t. It can all be very confusing so let’s do something to help clear that confusion, shall we?
Our first step to understanding electricity ratings is to know how to convert one to the other and the difference between the two main ratings.
Before you can convert one to the other, you have to know what type of circuit is being used. With direct current, the kW and kVA are the same because the current and the voltage are in phase. If you have a DC current, therefore, either reading applies. If you are using an alternating current, on the other hand, the kW reading will tell you what the actual power is, and the kVA will tell you what power it is capable of. To convert the one to the other, you would need to find the Power Factor for the particular device that you are going to use.
The equation itself gets complicated, so we advise using an online converter like the one at
So, what is the actual difference between the two, then?
- KVA electricity denotes the apparent power.
- KW in electricity shows the useful or active power.
So, the kW is the power that we have to work with. The kVA is more like the potential power.
Again here, it depends on the kind of current that is being used. When it comes to an alternating current, only a portion of the kVA can actually be usefully used in the home to do work. With alternating current, the amount of power available at any one time depends on the load on the circuit.
The more lagging there is, the less power will be available for use.
With direct current, the potential power and the apparent power are the same because you have direct access to all the current. So, it is better to check the kW rating when checking what voltage your device needs.
Household Items consumption
Different appliances need different amounts of electricity to run properly. Think of it this way. Your power bank can usually charge your phone pretty effectively but is not able to charge a tablet because the power requirements are much higher.
You need to know what the appliance’s power requirements are so that you can be sure it will run properly, that it can handle your power supply, and to ensure that it won’t overload your power supply.
If you are unsure, you can always ask a salesperson, check the manufacturer’s website or phone the manufacturer’s helpline.
If the device is not getting enough power from your home circuit, it won’t perform properly. Should your power supply be too strong for it to handle, it will get blown out. If it draws too much power from the circuit, it could overload your circuit.
As a result, you should always be sure that you check the actual electricity watts that your device requires.
– Reference Video: Learning Engineering