Remarkable! It's been awhile since I used to be a factory authorized service tech for Miller back in the eighties but as far as power factor correction is concerned, when I made my first post, I did'nt even look at the manual, and was only going from my memory which is'nt the best way to go so, I did'nt even know if it was included with the deltawelds 452's...
I do know that back in the day, one could order PFC (Power Factor Correction) with the 3 phase units because, I personally installed twenty of the then Miller delta weld 600's, and thirty-two Miller Intelliweld's@ the old GM assembly plant in North Tarrytown, NY!!! I even rebuilt two transformers, and changed many a motherboard, SCR's, hall devices, added Capacitors, PFC banks, and many other components due to how terribly they protected those power sources from hi freq coming from other sources, and yet they did'nt do anything to prevent the hi freq from infiltrating the equipment!!! Go figure!!!
The result would be a disruption of the internal harmonics from an outside source combined with then unconditioned 3 phase primary input power lacking a VAR automatic switching capacitor circuitry for "Active"
PFC as opposed to what we ended up doing as a less efficient solution which was to install "active" PFC for each power source... Talk about Capital Equipment Tax write offs!!!!
Power Factor Correction can be used, and is commonly used in the form of active type power factor correction with localized 3 phase power sources such as a Miller deltaweld 600 or the Deltaweld 452 if ordered as an option from Miller but, it does'nt come standard. Single phase power sources usually use a form of "Passive" PFC which normally consists fo a bank of capacitors and resistors for filtering which will only compensate current fluctuations and are used primarily with single phase primary input.
Power Factor Correction compensates current fluctuations that were notorious (less than a factor of one) in certain parts of NY state and especially in the greater NYC metro area.
here's wikipedia's explanation in order to clarify what 357max meant:
http://en.wikipedia.org/wiki/Power_factor_correctionHere's more to read on PFC:
http://www.ibiblio.org/obp/electricCircuits/AC/AC_11.html#xtocid88953http://www1.eere.energy.gov/industry/bestpractices/pdfs/mc60405.pdfhttp://www.onsemi.com/pub/Collateral/HBD853-D.PDFhttp://freeenergynews.com/Directory/PowerFactorCorrection/index.htmlhttp://www.dansdata.com/gz028.htmhttp://www.fairchildsemi.com/an/AN/AN-42047.pdfhttp://www.endpcnoise.com/cgi-bin/e/pfc.htmlLineVoltage Compensation is sort of another form of power factor correction that compensates for fluctuations in line voltage which makes it different than normal known Power Factor Correction circuits. Nonetheless, if your line voltage is'nt compensated in a sufficient amount of time, your power factor can become less than one which would then require one to have PFC in the first place... This can be achieved by installing what is known as a an "Active" Power Factor Correction circuit.
Having both types of circuits installed locally such as part of the power source itself is extremely beneficial in locations throughout the country where there are known conditions whereby at certain times of the workday, both Line Voltage Compensation, and Power Factor Correction or better known as "Active" PFC is required, and must be installed locally in order to keep the factories, and shops humming like a symphony as opposed to sounding like having the harmonics of a Heavy Metal Rock band due to the fluctuations of Line voltage, and current changes. The power companies use both as the customers locate further, and further from the substations.
So I respectfully disagree that power factor correction is only limited to single phase power sources because, it all depends on what type of PFC is being used which for single phase usually means a passive form of PFC.
Respectfully,
Henry... You know - like the unit of electrical measurement!!! :) :) :)