Home PF Correction?

[mivey]

Just because it isn't itemized or measured on a small scale doesn't mean you aren't paying for it and that it isn't measured in aggregate for larger areas.

If a customer wants to contribute money to help out everybody on the system, that is up to them. They are not going to get a direct ROI, and will continue to pay for a portion of the utility's var correction costs.

In other words, I can pay to get my house to a unity power factor but I'm still going to pay for a portion of my neighbor's bad power factor.

 

[gar]

080703-1212 EST

I bought a GE 89624 so called dimmable CFL this morning, without tax $14.

The device is interesting, but I would not call it dimmable.

At the same time I bought the least expensive dimmer, $5. This dimmer is a two wire device, and a ground wire that is not part of the function. Two means all power to function the device comes from current thru the load device. Turn on of this dimmer is at maybe 45 degrees and phase shifts from there.

Back to the CLF. It is not dimmable with a Powerstat. In fact it is close to a constant light output from 120 V down to about 95 to 98 V. At 95 to 98 V it just quits. With a constant power load, which constant brightness might imply, the input current increases slightly as voltage is decreased. This happened.

The GE CFL had a much better current waveform then the previously mentioned Commerical Electric lamp. The GE had a nice rounded peak and therefore lower amplitude high frequency components. Still it is narrower than the Tektronix I previously mentioned. Peak amplitude is about 0.6 A and starts at about 1.8 MS (38 degrees) and terminates about 90 degrees. Clearly this will produce a leading power factor like the Commerical Electric.

With the phase shift dimmer control no dimming occurs until the turn-on phase angle is somewhat past the peak of the input current pulse. Then there is only a small change in phase angle to produce the very limited adjustment range.

With a phase shift dimmer that could more closely approach 180 degrees low end dimming might be better. But nothing comparable to incandescent lamps from a dimmer type Powerstat. These have a non-linear winding.

Note: both CFLs had a leading power factor and you do not compensate these with capacitance.

,

 

[Jraef]

If a customer wants to contribute money to help out everybody on the system, that is up to them. They are not going to get a direct ROI, and will continue to pay for a portion of the utility's var correction costs.

In other words, I can pay to get my house to a unity power factor but I'm still going to pay for a portion of my neighbor's bad power factor.

That's right. Essentially you can be a "good citizen" and reduce your VAR demand on the PoCo (by some infinitesimal fraction of your total demand), but they are not going to reward you for it. In fact even if EVERYONE did that, they would still not pass the savings on to the residential consumers. They have PUC edicts that require them to maintain the capacity anyway. Bottom line, buying these (essentially worthless) devices will net no financial benefits to anyone other than the manufacturer of the devices.