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Posted

Is anyone familiar with this product? http://www.poweroptimizer.com/index.htm

I've never seen one on the job. They do have a product for residential use. From the site:

The Power Optimizerâ„¢ works to reduce heat and electrical vibration by stabilizing the current and training the electrons to flow more efficiently. The result is a lengthening of the electric wave and a narrowing of the flow along the center path of the conductor. A more efficient current meeting less resistance along the path of the conductor gets more of the purchased power directly to the workload.

Posted

I think it's actually what I refer to as a 'power conditioner'. Harmonics are generated by certain types of non-linear electrical loads (computer power supplies, ECM motors, switching power supplies, etc) and since they are at higher frequencies, they tend to increase the heating of conductors which wastes your money. Power conditioners reduce the presence of these harmonics.

The company has apparently invented a new and mysterious term for power conditioners with vague descriptions in order to make it easier to sell to savvy deprived clients.

Just my opinion.

Marc

Posted

I think it's actually what I refer to as a 'power conditioner'. Harmonics are generated by certain types of non-linear electrical loads (computer power supplies, ECM motors, switching power supplies, etc) and since they are at higher frequencies, they tend to increase the heating of conductors which wastes your money. Power conditioners reduce the presence of these harmonics.

The company has apparently invented a new and mysterious term for power conditioners with vague descriptions in order to make it easier to sell to savvy deprived clients.

Just my opinion.

Marc

I've sat through a couple of presentations for harmonics filters, and remain unconvinced of their value. Thankfully, we don't have harmonics on 120/240-volt systems. The only residential harmonics problem I ever encountered was a condo with 3-phase 120/208 power and lots of electronic dimmers and personal computers. Even then, it wasn't enough to cause the problems you see in commercial and industrial systems.

Douglas Hansen

Posted

Harmonics result from non-linear loads. Doesn't matter what the power configuration is, as long as it's AC. About the only non-linear loads in residential is ECM motors on air handlers, florescent lighting and some power supplies for computers, printers, etc. Like you say, in residential it's not enough to be a problem.

Marc

Posted

The control freaks will love the idea that they can "... reduce heat and electrical vibration by stabilizing the current and training the electrons to flow more efficiently." (emphasis mine)

I hate those damned independent electrons that won't take orders.[;)]

Posted

Harmonics result from non-linear loads. Doesn't matter what the power configuration is, as long as it's AC. About the only non-linear loads in residential is ECM motors on air handlers, florescent lighting and some power supplies for computers, printers, etc. Like you say, in residential it's not enough to be a problem.

Marc

I don't 100% agree Marc. Here is how I see it: While harmonics do indeed result from non-linear loads, not all non-linear loads produce harmonics. It depends upon the power source. I don't think you can get harmonics on a system originating in a single-phase transformer, even though you connect non-linear loads to it. When you connect those same loads to two (or three) phase conductors and a neutral of a 3-phase system, then you have additive harmonics on the neutral.

Non-linear loads draw current at frequencies other than 60Hz. It doesn't matter what those frequencies are when the two phases are 180 degrees from each other; the loads on a shared neutral can never be additive. Put those phases 120 degrees from each other, which you have in a 3-phase system, and the non-linear frequencies do line up and result in a harmonic current.

I've seen some spectacular meltdowns of neutrals in 3-phase systems, including one where the utility replaced a single-phase transformer with a 3-phase and hooked up just 2 legs to the customer's original service. I've never thought it possible to have the problem on a single-phase system. Am I missing something?

Thanks

Douglas Hansen

Posted

I don't 100% agree Marc. Here is how I see it: While harmonics do indeed result from non-linear loads, not all non-linear loads produce harmonics. It depends upon the power source.

The only role that a sinosoidal power source has in the generation of harmonics is a result of the impedance that's within that source. Harmonics that are present in the current flow will pass through the voltage source. When they pass through the impedance that lies within the source, the output voltage waveform is affected. The harmonics are much more pronounced in the current flow itself and distortion in the current waveform is more easily seen. It's quite simple and is purely mathematical: any alternating waveform can be produced with the right assortment and magnitudes of sinosoids.

I don't think you can get harmonics on a system originating in a single-phase transformer, even though you connect non-linear loads to it. When you connect those same loads to two (or three) phase conductors and a neutral of a 3-phase system, then you have additive harmonics on the neutral.

Multi-phases presents possibilities with harmonics that you won't see on single phase but that doesn't mean that harmonics don't exist on single phase systems.

Non-linear loads draw current at frequencies other than 60Hz.

Yes, that's my point. Non linear loads create those frequencies in the current flow and they are superimposed upon the 60 Hz waveform to produce what you see when you view the distorted current waveform on an oscilloscope.

It doesn't matter what those frequencies are when the two phases are 180 degrees from each other; the loads on a shared neutral can never be additive. Put those phases 120 degrees from each other, which you have in a 3-phase system, and the non-linear frequencies do line up and result in a harmonic current.

I agree. The concept of shared neutrals does not apply to single phase systems. A 120/240 system is not a multi-phase system like 3 phase.

I've seen some spectacular meltdowns of neutrals in 3-phase systems, including one where the utility replaced a single-phase transformer with a 3-phase and hooked up just 2 legs to the customer's original service. I've never thought it possible to have the problem on a single-phase system. Am I missing something?

Thanks

Douglas Hansen

Just the mathematics. Nothing more. I'll look in my college texts for a better explanation and get back to you, provided that I can do so before Mike O hits the tilt button and forever banishes me to another dimension for this mathematical transgression.[;)]

Marc

EDIT: The explanations in my books aren't any easier to understand. Sorry. If you have a colleague that has a graduate degree in mathematics, you might consult with him.

Posted

So what's the verdict. Do I need one or not?

Let me think about it for a minute.

Not. [:)]

When you start hearing buzzing, screeches and whistles coming out of your television set and audio equipment, that's when you need one. The most economical of those devices don't have sufficient filtering to block out.....

Never mind.

Marc

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