Has Anyone Tried These Home-Capicitator Gadgets?

[MikeFerrara]

Charlie is of course correct. The only thing I would add is that some Industrial applications do measure and bill for reactive power. The meters used measure all sorts of neat things that your residential meter doesn't.

You can certainly hook a cap up across an inductive load like a fan and show that the current goes down. Iin fact, if the magnitude of the cap impedence is equal to that of the inductor, the current will drop very near zero...if you had a perfect cap and a perfect inductor, it would be zero. However, if you check the meter outside on your house, you will see that nothing changed. Residential meters measure REAL power. Also note that I mentioned "perfect" caps and inductors. They don't exist. Real caps and inductors also have resistance...ie, the impedence is not at an angle of +/- 90 degrees. So, when you hook up that additional load your real power consumption will actually go up a bit and cost you a little more...Edit: I should add that the extra load would be balanced by the fact that IF the cap was physically located close to the inductive load that you would save some IR loss in the house wireing. I can't see that being significant though and if that savings is even measureable I'd guess it would take a long time for it to pay for the stupid cap. LOL

 

[DennisW]

Wonderful explaination Charlie, assuming everyone is an Electrical Engineer. My wife and I are both Electrical Engineers, so we understand, however, it's been 30 years since I took the power class.

Basically if you have a whole lot of big electric motors, you can use capacitors to reduce the inductive load, thereby saving quite a bit on your electric bill. This is why the big industrial users hire Power Engineers. They pay for themselves.

For the normal household? You don't have enough inductive load to be able to show any decrease worth the cost of a gadget that is pretty bogus.

Charlie, you are truly a geek, and yes, it takes one to know one.

 

[MikeFerrara]

Wonderful explaination Charlie, assuming everyone is an Electrical Engineer. My wife and I are both Electrical Engineers, so we understand, however, it's been 30 years since I took the power class.

Basically if you have a whole lot of big electric motors, you can use capacitors to reduce the inductive load, thereby saving quite a bit on your electric bill. This is why the big industrial users hire Power Engineers. They pay for themselves.

For the normal household? You don't have enough inductive load to be able to show any decrease worth the cost of a gadget that is pretty bogus.

Charlie, you are truly a geek, and yes, it takes one to know one.

No that's not it at all. Your residential electric meter only measures real power I^2R as apposed to apparent power VA. You only pay for real power so correcting your power factor won't help you regardless of how inductive your load is. That's why it's bogus.

Industry is another matter and they do/may bill for VARs (volt amps reactive). They may also adjust billing based on "peak demand" and "time of use". In this case, the meters used do measure reactive power...but, again, the residential meter hanging on the side of your house does not.

 

[MikeFerrara]

ooops, I should add a disclaimer here. I've been out of the power distribution industry for a couple of years now so I suppose it's possible that there are some places where residential is paying for reactive power though I doubt it.

 

[Darnold9999]

I particularly liked this line:

"Therefore, the amount of electricity purchased from the utility company by a power factor optimization has been greatly reduced, resulting in power savings for the home or office."

A conclusion, when parsed, that has no meaning but sounds like it does.