Electroflow Power Conditioners 1

[trosepe]

Does anyone have any experience, good or bad, with 'Electroflow Power Conditioners'. The claim is they reduce energy costs, system losses and harmoics and improve PF. They have been applied in plant that has 50% of the motor load controlled by VFD.

The plant load is 4.1MW and 1.4MVAR. There are about 1MVAR of these electroflow units connected at the main 480v swbds. They connected them in parallel with existing feeder circuit breakers to the MCC's. The plant has approx 700KVAR of static capacitors connected at the larger 480V motors.

With all the electroflow power conditioners off, the plant PF os .89 and THD is 2.2%. They have been loosing an inordinate number of drives latley; just several months after the installation of the electroflow equipment. I have advised the to leave the electroflow units disconnected until the affect is evaluated.

They seem to be just switched capacitor banks. I am concered with over correction of the plant PF and resonance with the harmonics from the drives. Anyone that has experience with these or similar units please let me know what your experiences were. Thanks.

 

[jraef]

From their website it looks like they have multiple LRC tank circuits and a zig-zag transformer. The zig-zag is nothing new as a harmonics filter, the LRC tank circuits are a bit scary when it comes to drives however, for the exact reason you are suspicious of. It's wouldn't be hard to end up with a resonant interaction. They say they are "tuned", but how do you tune to a moving target such as a plant with that much use being non-linear loads??

In general I was thinking the thing is somewhat benign and probably provides some power quality benefits,

http://www.electroflow.com/electroflow/electroflow.html

But then I read that they provide "...guaranteed 34% electrical savings" and it all crashed for me. That's the call of the snake-oil salesman in my opinion... To their credit, they stop short of saying "energy savings" but guaranteed? What if I buy one here in Northern CA where we have no power factor penalties? Would I get my money back from them when the "guaranteed" savings don't materialize?

I find that savings from improving power factor and power quality, while undoubtedly real, are almost impossible to quantify because there are waaaaaay too many variables. So when someone markets a device as being this simplistic, I find that suspicious and that leads me to question everything else they claim, including their "tuning".


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[jraef]

Sorry, too many edits in that posting. Savings from pf improvement are fine, it's savings from power quality improvement that I find difficult to quantify.

 

[LionelHutz]

Last time I ran across them, from what I could figure out they were just selling capacitors.

The salesman was so proud to tell the story of a very satisfied plant where they showed the current was reduced when their equipment was turned on, which was implied to mean the customer would save so much money on their hydro. Big deal, correcting the power factor always has the effect of reducing the current.

Their "proof" was pages (very crappy pages at that) of calculations and vector drawings showing how a capacitor would correct the power factor and boost the voltage and other such stuff. Once again, big deal. The capacitor is not intelligent and it won't selectively boost the voltage on a low phase. It won't selectively target certain harmonics. The interaction is what it is, not what you hope it to be.

As for how they would impliment a system to ride-through a 1 second power outage? Well, they would not answer how they would do it but they were indicating it would not require transfer switches or UPS equipment or any other such devices. Just their unit connected in parallel to the incoming power. This sounds like complete bullshit to me. There would be no way you could ever prove if it worked because your incoming voltage and the "backup" voltage are paralleled together. Also, say the power to your whole area went out. The system would need to be capable of powering your whole neighbourhood for a second? Not likely.

 

[pwrengrds]

There has been a lot of comments on electroflow on this web site, do a search. For a pf controller it works ok, the one I dealt with the controller board had to be replaced with a pf controller off the shelf due to quality control problems of the electroflow boards. It's much cheaper to just buy a PF controller with some tuning if needed.