Son Agro Ballast Q for Electrical Engineers

[Bryan]

From the info I have been able to pull from the net the Advance transformer SON AGRO ballast has a power factor of 0.8 which gives the draw of the ballast approx 5.2 amps at 120 volts(whew).

http://www.advancetransformer.com/ec...1627985351.pdf


The Universal/Magnetek SON AGRO ballast doesn't give a power factor but draws considerably less power. Specs state 4.30 amps at 120 volts.

http://ultballastspecs.tsqrd.com/hid/S430MLTAC4M.pdf

Any enginners out there that can comment on the difference between the two ballasts. Seems the Universal ballast would probably be more economical to run.

[StirCrazy]

Bryan, My guess would be that the power factor on the magnateck is 0.9 which would account for the differences..

Hmmm to bad they have no prices on that page.. would be interesting to see how the prices compare.

Steve

[Bryan]

I am going to call around next week and see what I can find out.

[rossb]

I am reaching back into my memory a bit but I think it goes something like this. The power factor is not something that you can control, it is controlled by your electric utility. The AC electricity that arrives at your house has a sinusoidal waveform. A very simple analogy would be to think it of as two phasors that roughly are the voltage and the current. If these waveforms arrive at your house in phase then the power factor is 1. If they arrive out of phase then the resultant power that you get is reduced. Altought the mathmatical calculations are not trivial if they are 45 degrees out of phase the resultant power would be about 70 percent of normal If they are 180 degrees the resultant power would be 0. Typical power factors in residential areas are in the region of .8 to .9.. So when you select a ballast the power factor consideration relates to the power you receive. If you have a high power factor (.9) you select a high power factor ballast. If you have a power factor of .8 you select a ballast that operates at that PF. Your lighting supply or local utility can tell you what your power factor is.


So if you have a 1000 W light, and assuming .8 power factor, you have to supply 1250 Watts. Also the ballasts are not 100% efficient so I expect to get 1000 watts of light it takes about 1400 watts.

Basically power ~= voltage*curent*powerfactor

[StirCrazy]

naaa, it is in the ballast.. a .8 PF and a .9 PF ballast will use different amountes of powr on the same circut.. this is why you should het HP factor ballasts when you can to save on your power bills..

Steve

[Bryan]

Forgot about the Venture ballast. It has a rated power factor of .9 drawing 4.55 amps

http://www.venturelighting.com/Balla...ame%20Page.htm

In order of efficiency we have

Magnatek/Universal 4.3 amps power factor unknown
Venture 4.55 amps 0.9 power factor
Advance 5.3 amps 0.8 power factor.

I guess the power factor of the Magnatek exceeds 0.9 which i didn't think was possible with HID ballasts. Hmm

Originally Posted by StirCrazy

Bryan, My guess would be that the power factor on the magnateck is 0.9 which would account for the differences..

Steve

[StirCrazy]

Or they are rating it slightly different.. we have seen that befor with pump motors here befor..

Steve

[rossb]

steve wrote

naaa, it is in the ballast

Good point. I had forgot about the inductive/capacitive nature of the ballast. This actually makes things worse.

Check this out for an even scarier picture.

http://www.sylvania.com/forum/pdfs/faq0002-0297.pdf

It makes one really want to research a CF before they buy.

[DJ88]

Forgot about the Venture ballast. It has a rated power factor of .9 drawing 4.55 amps

You just discarded the most efficient of the ballasts. .9 means it is 90% efficient. .8 is 80% efficient.

And pf is entirely determined by the LOAD after the supply arrives a your home. Not by the Utility company. If that were the case then all the large electricity users such as manufactiring would be getting screwed royally. They pay depending upon how good or bad the powerfactor they are running. Less than 75% they pay almost 20% surcharges(if I remember right). That is why all large end users try to adjust the pf of thier shop to as close to equality as possible. 1.0 or 100%. This is done by finding out whether they are running and inductive or capacitive shop and then adjust accordingly with capacitor banks etc.

Unless you are wanting to run many many units of a NPF ballasts, I wouldn't worry that much about whether you buy a HPF or an NPF. the differences between the two in this case where you are running one maybe two ballasts aren't going to be so extreme as to make a huge difference in our montly bill. That warning that you saw regarding running many NPF ballasts is generally only found in large end users. Not home use. If you were to start drawing so much power that you were up in that category the cops would be visiting you very shortly looking for a grow op. And a BIG one at that.

The amount of money you will save if you are running one ballast of the same wattage where one is a .8 NPF and the other is a .9 HPF ballast will end up being counted in the cents per MONTH ie. Less than one dollar. Basically PF in this hobby will not have a drastic effect on savings going back into your pocket. If you are already running or intend to run a 400W ballast the difference will not noticeable.

Basically, buy the ballast that works how you want it to or works the best. Don't go buy a .5 mind you. But the .1 you are talking about doesn't have that big a change. We aren't high end consumers of electricity. When you measure your daily use in the hundreds of kilowatts or more then start worrying about pf. Here it is a waste of time. You could be enjoying a beer with the energy you are putting into finding out all this info.

[Troy F]

:shock: