The Electrical Harmonizer 4

[djohnst]

A supplier is offering to sell us an Electrical Harmonizer which he claims "Optimizes incoming voltage to appropriate utilization level" for energy cost savings.
This device is actually a step-down transformer that reduces the voltage by about 6% from say 485 volts to 455 volts, the idea being to reduce the voltage to a level that is still within the operating range of the equipment within our building, but since P=E*I reducing E should result in lower P consumed and thereby lower energy costs.
The supplier has impressive documentation that confirm the savings.
My questions: Has anyone had good or bad experiences with this type of product? Does anyone know the long term effect of operating equipment such as fluorescent lights, or chiller, fan and pump motors with variable speed drives at slightly reduced voltages?

 

[buzzp]

The EPRI has done some studies on reduced voltage to save energy. One document is from 1984 but the principles still apply. It is called "The Effects of Reduced Voltage on the Operation and Efficiency of Electric Systems". EPRI EL-3591, Project 1419-1.
There is some hard test data in this document and you will probably be somewhat surprised at its conclusions. The bottom line is, every place is different and must be considered seperately.
This is from a reputable source with no outside influence (hopefully). There seems to be a wide variety of opinions on this but the concept does work for some energy users. The report is well worth reading.

 

[jtkirb]

if the guy sells magnets that attach to your water pipes as another product line- show him the door.

JTK

 

[jraef]

That is a well done report, even if it does appear to have a slight bias. CVR is of course nothng new under the sun, but they state the case well. I will concede that there may be a benefit to this device if truly used with the prudence discussed in that article, because CVR will work better for some and worse for others. Essentially this is point-of-use CVR, so a user who can benefit from it will be able to do so without the utility doing it, which would adversely affect the others.

One thing they may have left out of the equation however was the cost of engineering services they say (and I agree) would be necessary before implemeting this. If your facility already has a qualified EE on staff who can do a thorough site study, no problem. If you need to hire this out, that needs to go into the capital cost part of the payback formula. I would not trust a vendor to do a survey for me, they tend to "skew" data to justify the time they invest in doing the survey.

I also take a litle umbrage with this statement from that scenario;

The lighting systems compensate for the lower voltage levels by producing less light. Since the facility is still well lit, this does not cause any problems.

That is a big ASSumption! I did lighting system design for a number of years, and lighting levels on work spaces are a critical element. One canot ASS-U-Me that every lighting system is overdesigned. Most well planned ones are not.

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[waross]

On the practical side,
stevenal said it before I got a chance.
See if the utility will drop a tap on the transformers.
Quick, cheap, and reversable.
On the lower voltage lighting comments;
Years ago our company was asked by a department store to install a large number of incandescent High-light fixtures over the display areas. They called for a set of buck transformers to reduce the panel voltage by 12 volts. Their maintenance chief told us that the energy savings would pay for the transformers. He then mentioned the labour cost of having to move a large part of a furniture display to replace a burned out bulb.
"With the reduced voltage the lamps last several times as long. The really big saving is in relamping labour costs."
yours

 

[mc5w]

Reducing the voltage to quartz halogen bulbs can actually DECREASE the life. There are 2 mechanisms involved:

1. If the bulb is too cool tungsten chloride and tungsten bromide will not boil off of the quartz envelope. This leads to excessive depositation of tungsten on the inside of the quartz envelope.

2. The filament normally burns hot enough that when the tungsten chloride or bromide hits the filament, tungsten redeposits on the filament and the clorine and bromine turn into free gas. If you burn the filament at too low of a temperature tungsten does not redeposit.

If you want to do dimming what you want to do is to turn off bulbs in a chessboard pattern. By judicial selection of bulb wattage you can have 3 light levels just like a 3-way light bulb.

If you want analog dimming that preserves lighting efficiency then you need to do fluorescent dimming. However, dimming ballasts have a tendency to be h#!!atiously expensive.

 

[waross]

Hi mc5w
How much under voltage can quartz halogens accept without problems?
Thanks
yours

 

[davidbeach]

You can run the halogen lamps at what ever dimming level you want if you run them at full output for 15 minutes per week. You can greatly extend their life my limiting them to 90% of rated voltage for all except those 15 minutes per week.

 

[jraef]

Wow, that is interesting, and heretofore completely foreign to me. That explains why I lost quartz bulbs in portable floodlights so much faster after installing dimmers. Workers complained that the lights were too hot to work under, and they didn't need all that light most of the time anyway, so I had them install dimmers on the control panels. The bulbs lasted less than 1/2 their previous life. I guessed it was harmonics from the electronic dimmers causing vibrations in the filaments.

Well, I'm done for the day, I limit myself to one new bit of knowledge per day.

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