Power Factor correction with CFL bulb question?

JohnMassa wrote: »

Bill,

I stand corrected, A local 120VAC generator feeding a 25W CFL bulb with 0.5 power factor will pull 25W/0.5 = 50 VA. On a 120VDC generator or 120V battery the draw will be 25 VA. The AC generators are a better choice as many appliances cannot use DC.

It seems that multiple transformers and long transmission lines should cause more losses due to poor power factor than does an on site generator that doesn't have losses due to multiple transformers and long transmission lines. The main losses must be primarily in the generators?

John

John

BB. wrote: »

Inetdog,

I know you deleted your post--But I believe you where correct--The office computer issue was a neutral return current problem and probably because the current spikes did not add up to "zero" in the neutral line for a Wye phase circuit (common for 120/208 VAC 3 phase power for an office park in California). 'Twas 35 years or so ago when I heard about the problem--stuff is a little fuzzier now.

-Bill

BB. wrote: »

PF issues have hit large companies before (decades ago, a local credit card processor using a whole building full of, then new, PC's kept burning out wiring and popping fuses--even though the the circuits were well under the power ratings--bad PF was the cause).

-Bill

The biggest problem was in office cubicles with built-in wiring. They were supplied with 3-phase power, and for PF=1 loads the neutral would never have to carry more current than any one of the hot lines. But with computer loads, the neutral was carrying three times as much current as the phase wires. Poof!
Beyond that, the peak phase currents were also more than the circuit was capable of even though the RMS values were OK.
And the final straw was that the current was in fact higher than you would expect from the wattage because of the poor PF.
Circuit breakers do not care specifically about the PF or the wattage, they just trip from current. (Usually RMS current, but.....)