Understanding Rated Power: Calculating with Voltage Range for Household Devices

[keehweelaw]

hi all,

am a little confusing with the rated power stated for a product / device. usually we will see product with voltage range 220V - 240V, power 53kW. so this 53kW is calculated by using 220V or 240V or 230V? as different countries have different power supply to the households; i.e. Australia using 240V, China 230V and EU 220V...

 

[I_am_learning]

If you hook it to 240V system it will consume lightly less current than if you hooked to 220V, in such a way that the power would be 53KW in both case.
Ideally.

 

[keehweelaw]

nope...in real time it will consume more than 53kW if the device is connected to 240V...and it is 53kW at 230V...

i am just wondering, what is the norm way for people to indicate this on a product?

 

[Studiot]

Under UK and now European law all electrical devices have to carry a 'rating plate' which states, amongst other things, their power consumption at standard voltage.

Since harmonisation the standard voltage throughout the EU is 230 volts.

Some devices, mostly electronic ones, will have internal regulators to draw the same power regardless of the input voltage, within their range.

Other devices such as resistive heaters will draw more or less power according to the actual line voltage.

go well

 

[keehweelaw]

thanks Studiot.
so i ll consider 53kW at 230V is correct in doing labeling for a product...

 

[Studiot]

Yes indeed.

You can either state the voltage and current or the voltage and power, you do not need all three.

But if this is a real product or an exercise you should consult your own electricity regulations for details of what else needs to be on the rating plate.

Some products now have to show energy efficiency ratings as well.

Please note that responsible manufacturers often add additional non statutory information that common sense dictates.