Apparent Power ain’t True

24Jul09

power_factor_physics_tshirtManaged to get overly keen with an Owl power monitor and discovered a whacking 55w on an induction hob when switched off but not isolated.

So the vampire appliance is clearly in the dock looking guilty and as a planet saver I’m angry as hell.

The technical bit follows because the real chargeable power used when measured accounting for power factor is a whole lot less in the region of 6w not the panic stricken 55w.

This is explained because the Owl meter measures current and has no way of measuring the voltage or power factor. The hob will have a mains suppression capacitor which means that the standby supply current will be out of phase to the voltage and be mostly a capacitive load. Although this uses current this would not be measured by a true power meter and not be charged by the electrical supply company.

Phew, false alarm, panic over.

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One Response to “Apparent Power ain’t True”

  1. I won’t get a power saver then!


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