PFC

[tanner0441]

Hi

I used to do power factor correction at one company I worked for and it consisted of a lot of measuring, maths, and lots of time with a AVO circular slide rule, and switching in or out capacitors or inductors.

As it was only £20 I have bought an electronic device that is reported to do the same thing for domestic situations. It is suposed to balance the power factor for washing machine motors, fridges and freezers, and anything else inductive. I was told if I am not happy just return it for a full refund.  They were talking of 5 to 20% saving so see what happens.

So if anyone has experience with these things or know how it workes I would love to know.

Brian

[wooferhound]

is PFC

Power Factor correction ?

[tanner0441]

Hi

Sorry yes.

When you have an inductive load on an AC circuit the current waveform can lag the voltage waveform, power factor correction is to bring them into line and make things more efficient, and cheaper to run.

Brian

[independent]

As far as I know 100% PFC correction doesn't cost you less.

Here, where I live, we don't get billed in VA we get billed in watts. Only industrial users get billed in VA, that is actual, measured, Volts times Amps. So, when you have something, like say a fridge, and it's compressor is running at 33% efficient PFC you are only paying for a 1/3 of the amount of power you are effectively using. The advantage of using an appliance with 100% PFC correction is that there are less harmonics in the electrical system, however, you end up paying more to use the device than if you didn't correct it.

HTH

[Flux]

That is certainly true in the UK. Domestic metering is kWh not KVA so power factor correction saves you nothing.

If you have a long line to your property and voltage drop is a big issue with heavy loads then PFC may reduce the line current slightly and reduce this volt drop.

Also PFC only works with linear inductive loads, it will work for transformers and motors but will not correct for screwed up power factor caused by electronic switching power supplies and similar things where the low power factor is caused by waveform rather than phase angle issues.

Industrial users are penalised for running at low power factor and correction is worth the cost.

Flux