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If I'm not wrong, all consumer electrical devices I encountered before they mention the power spec as consumed power meaning active power.

But I stumbled upon a device spec showing power as VA not W. Power input: 90 VA. Can this be typo? And if not, what would be the reason to write apparent Power (VA) which is the power combining both active and reactive power. They don't even mention power factor so impossible to calculate active power.

Here is the section of the specs taken from this page:

enter image description here

Is this a practice which can be deliberately done?

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  • \$\begingroup\$ This is a common practice for giving power in VA. So where is the problem? \$\endgroup\$ Commented Jan 12 at 14:50
  • \$\begingroup\$ From the consumer side it doesnt tell anything about consumed power in W. It doesnt show power factor to derive the active power. \$\endgroup\$ Commented Jan 12 at 14:52
  • \$\begingroup\$ Well, you can assume the maximum power this device will consume will not exceed 90W. \$\endgroup\$ Commented Jan 12 at 14:59
  • \$\begingroup\$ There's an "inquire" button on the link so, have you tried asking them? I mean that nobody here is going to inquire on your behalf and, it's unlikely that any answers will be anything other than guesses (unless of course some has one in their position and is willing to make a measurement). \$\endgroup\$ Commented Jan 12 at 15:23
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    \$\begingroup\$ from an user POV the apparent power is relevant to ensure proper installation (e.g. grid load) or why do you assume the real power should be listed? \$\endgroup\$ Commented Jan 12 at 15:27

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The VA spec. is actually very important for designing systems with devices that draw reactive power.

Take for example a 120V AC device with a power rating of 120W (and a power factor PF of 10%).

If you have to provide cabling for this device connected to a power source, how much current does your cable need to handle?

120W/120V=1A would be the wrong answer, because the RMS current would be 10A, actually (= 120W/120V/PF).

So the 1200 VA specification easily lets you determine the max. cable current: I = 1200 VA / 120V = 10A.

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