TVSS and such

[sii]

Just as I was leaving today I got an email saying that I am to escort a representative from Utiliguard through our plant on Monday morning. They are pitching "a device that takes electrical spikes and moves the excess to ground" and "the potential to save us 15 -20% of our energy costs." I'm guessing a TVSS for the first claim and PFC for the second claim. Quotes are from an email forwarded directly from the rep.

My extremely limited understanding of PFC from a class I took a long time ago is that it can only save you money if your POCO has a power factor charge. Their site claims to reduce the KWH on your bill, I can't see how that's possible.

My main concern is that the VP of Operations, who originally contacted this company is the kind of guy that once he gets an idea in his head, you cannot convince him otherwise (it took me four years to convince him that just because his garage has three wire that doesn't mean he has three-phase power). I'm going to try to be open-minded regarding this, although my default is usually skepticism...I don't want to go into this with an unjustified negative opinion.

Most of this stuff is a little above my pay grade so I'm looking for some guidance to assist me in being able to have a constructive conversation with this rep. I'm also curious to see if anyone here has dealt with this company directly.

Link to site: http://www.utiliguard.com/

TIA

 

[gar]

110225-2146 EST

In my opinion they are snake oil salesmen.

The specifications look real important to an uninformed person.

I could not access any of the small tabs, only the .PDF files. The .PFD do not really describe how the product works. But your guess would be my guess also, transient limiters, and power factor correction capacitors. The oscillograms at the top and the labeling seem to be misleading.

No place did I see anything describing what is in the box. Suppose it is an MOV in parallel with a capacitor. MOVs are not a real sharp clamping device, also have a substantial variation in clamping voltage relative to the nominal value, although they are pretty good at clamping. Clamping at 130 V makes no sense. You would chop off the top of the sine wave and burn up the transient limiter. I would expect one to chose a clamping voltage at maybe 250 V for a 120 RMS sine wave.

The technical and other descriptions have too many missing links. Things that just do not correlate. For example, lack of the units of measure, like on capacitance. What does capacitance of 19,000 per leg mean. Is it 19,000 farads? Quite obviously not. Is it 19,000 microfarads? You still could not afford this in a several hundred volt Mylar capacitor for a home. Is it 19,000 picofarads? Too small to do any useful power factor correction.

Too many loose statements that seem to be OK, but may not be OK without further qualification.

In a typical home or business how does the placement of a power factor capacitor, even if optimized for a particular motor, from line to neutral at the main panel reduce the power losses in said particular motor? Probably virtually no change, thus no improvement in motor efficiency.

It is too much work to go thru all of their statements and show the problems that exist with the statements.

.

 

[steve66]

I second the snake oil salesman theory.

If it were that easy to save 15-20% on your energy bill, we wouldn't have all these energy code requirements electrical designers have to learn to deal with.

 

[ron]

Let him install it on your service on his own dime with an upstream disconnect. Measure kWH for a typical day with it off, then with it on. If it works, then buy it.
I suspect that he will just abandon the issue.

 

[mivey]

I see nothing wrong with using surge protection but with the amount of other junk related to energy savings posted on the site, I would not trust these guys. If you want surge protection, it is better to go with a company that does not lie to you. If they will lie about one thing, they would have no problems lying about another.

They may have a legitimate surge protection device but the trust factor alone would keep me away from them. I suspect the surge devices are mis-represented as well.

 

[mivey]

Let him install it on your service on his own dime with an upstream disconnect. Measure kWH for a typical day with it off, then with it on. If it works, then buy it.

That would not work unless you have a very stable load. Commercial load can vary a good bit from day to day. Better to test the device on a known load, not company-wide loads.

 

[sii]

110225-2146 EST
In a typical home or business how does the placement of a power factor capacitor, even if optimized for a particular motor, from line to neutral at the main panel reduce the power losses in said particular motor? Probably virtually no change, thus no improvement in motor efficiency.
.

So how would they go about sizng PFC equipment on a 480 volt 1600 amp service that has over a hundred motors connected to it? Wouldn't they have to do long term studies?

 

[gar]

110226-2005 EST

sii:

To answer your last question.

So how would they go about sizing PFC equipment on a 480 volt 1600 amp service that has over a hundred motors connected to it? Wouldn't they have to do long term studies?

The ideal way would be to put optimized power factor correction at each motor. Thus, when the motor is switched on and off so is the PFC. This automatically balances the whole plant, and minimizes unnecessary power loss in the wiring in the plant.

To do all the correction at the input to the plant means there is no power saving within the plant. In this case there might be automatic adjustment of the amount of compensation. Or maybe an average compensation might work. What you do in a specific case will be dependent upon on how the load and power factor change.

My comment that you quoted had to do with homes and small businesses, and also that there is probably no change in the efficiency of a motor with or without power factor correction. If anybody wants to demonstrate that power factor correction improves motor efficiency, then run the experiment as follows:

1. A stiff voltage source is used such that there is less than 0.1 V change in the voltage at the load under test, out of 120 V nominal (less than 0.1%), when either or both motor and power factor capacitor are the load on the voltage source.

2. Use a high quality wattmeter to monitor power input to the motor or motor plus power factor correction with no external mechanical load on the motor. The motor unloaded is at its worst power factor.

3. Do the test on an induction motor, and not a synchronous motor.


Homes and small business in most areas do not have a penalty for poor power factor. Thus, no saving in the customer cost if the PFC is at the main panel which is close to the meter. If the PFC is at the load, then there is a small saving. Then the question is whether or not the saving in energy to that one load pays for the PFC cost?

Unless the PFC location causes a change in voltage at the motor load it will have negligible effect on the motor efficiency. Improved motor efficiency would mean the motor would run cooler at the same mechanical load.

Most of the home show demonstrations use VA (volt-amperes) as the criteria to show an apparent power saving. This is a fraudulent demonstration. VA is not a measure of power on anything except a pure resistive load.

.

 

[highvolts582]

energy savings large buildings/idustrial

energy savings large buildings/idustrial

there are systems that involve using capaciters and moter controllers that involve heating airconditioning and machinery control that will help save money . if this equipment will save you money in stuff breaking from surges that could be viable. but I would not go into this thinking your going green or anything. not with a tvss anyway. you should be thinking solar energy and talk to a large hvac company that does energy control systems. Goethals bridge in new york has one of these systems. so does the courthouse across the street from yankee stadium has one of these.

 

[Besoeker]

My extremely limited understanding of PFC from a class I took a long time ago is that it can only save you money if your POCO has a power factor charge. Their site claims to reduce the KWH on your bill, I can't see how that's possible.

Depending on where it is located in relation to the load that it is being corrected, it may say some in I2R losses in the conductors. But nothing remotely close to the 20% being guaranteed.

Most of this stuff is a little above my pay grade so I'm looking for some guidance to assist me in being able to have a constructive conversation with this rep.

How about "Please close the door - on your way out"?

 

[Besoeker]

What does capacitance of 19,000 per leg mean. Is it 19,000 farads?

F:Mhz. F is Farads. Credibility in shreds
And the installation drawing looks very amateurish.
And the testimonials....

 

[sii]

Depending on where it is located in relation to the load that it is being corrected, it may say some in I2R losses in the conductors. But nothing remotely close to the 20% being guaranteed.

How about "Please close the door - on your way out"?

It sounds like this is a "facility level" product. I assume it automatically adjusts to correct the facility's PF.

My dad would always say "don't let the door hit you in the #$% on the way out."

 

[mivey]

Depending on where it is located in relation to the load that it is being corrected, it may say some in I2R losses in the conductors. But nothing remotely close to the 20% being guaranteed.

That's what bugged me.

How about "Please close the door - on your way out"?

:grin: