Author Topic: Electrical Power Saving Devices  (Read 3504 times)

Offline coutts00

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Electrical Power Saving Devices
« on: April 25, 2008, 06:03:58 PM »
I had noticed a posting on the list about power saving devices that plug into an outlet and slow the spin of the meter. A buddy who lives next door swears by these devices and has 2 of them, well we took one apart, it is comprised of a low farad high voltage AC Capacitor and a circuit for driving some LEDs.

In your average house you have 3 types of loads, Inductive, Resistive and Capacitive Loads.

  • RESISTIVE LOAD  (heaters and incandescent lights) The voltage and current peaks coincide and are therefore in phase and the power factor is in unity.
  • INDUCTIVE LOAD  (Motors and transformers) With an inductive load the current waveform is lagging behind the voltage waveform, therefore, the voltage peaks and current peaks are not in phase.
  • CAPACITIVE LOAD (Capacitors, wiring, cable) The capacitive load has a current waveform which is leading the voltage waveform, therefore the voltage peaks and current peaks are not in phase.

In the delivery of power a term called Power Factor comes into play. Power Factor is usually referred to as a number between 0 and 1. With a Resistive Load such as an incandescent lamp or an electric stove element, the power factor is 1 and all is good in the world. With an Inductive Load  such as a Ref, Fan or Aircon there is usually a drop in the Power Factor, sometimes as low as .45 but normally close to .70, this is not good and actually increases the wattage consumed. For a Capacitive Load such as a PC, TV anything using an electronic Power Supply including your CFL\'s the normal Power Factor is .85. With a power factor less than 1, devices convert some of their power into heat and the resultant energy is lost.

Enter the power factor correcting capacitor, when the Power capacitor is placed in parallel with the AC line it changes the power factor of the circuit and your devices run cooler, consume less power and cost less to run. It has been argued and proven in some cases that Power utilities actually charge you more for your power if you facility is sufficiently out of balance with respect to the power factor.

If you consider your AC for a minute, it has 2 motors, one for the compressor / condenser and one for the evaporator / fan unit, if either of these is running hot the unit has to overcome the internal heat load as well as the room heat load to cool, so the unit tends to run more often. In most window systems the thermostat is inside the unit, if the unit heats up it will affect the thermostat and the unit may come on unnecessarily. By bringing the Power Factor as close to 1 as possible the unit runs cooler and turns on only when needed to cool the room.

This is the same for your ref and your freezer. Those of us recently from the US are aware of Energy Star Appliances, these devices have the Power Correcting Capacitors already installed to make the motors produce less heat, and consume less power therefore they are more efficient. If you have a buildup of Ice in your freezer walls the device has to work harder to overcome the ice buildup to cool the food. If you look back at our Dome Building thread, heat flows from warmest to coolest trying to reach a point of equilibrium, so in the freezer, the warm food expels its heat to the cold walls of the freezer compartment, where the heat is taken away to the outside of the unit, if there is an ice buildup, the heat can\'t escape as quickly and the freezer works harder trying to bring down the temp of the food to reach equilibrium, i.e. frozen food. Enter Frost Free Freezers, a common device in Western Countries, it is uncommon here and most freezers have to be defrosted frequently to deal with the humid air that enters when the door is opened, and stays to form frost and then ice inside the unit.

So getting back to the power saver devices, as I mentioned they are just big capacitors. The capacitors themselves could be purchased for 200p not the 5000 - 7000 asked for by vendors. As to whether they actually work will depend on the overall power factor of the combined electrical load where you live and how much the power factor needs to be adjusted. Some are too small and improve your power bill a small amount, some are too large and actually increase your power factor and hence your load costing you more money. I would recommend building your own, start with a 10 microfarad 475 volt AC Capacitor, do a baseline test, and record your power meter for a day or two with a normal load, then plug it in and watch your power meter for a day or two, recording the same information. With the same load, did the meter spin faster or slower, if it went faster, reduce the capacitor to a 4.7 microfarad one, if slower try adding another 4.7 microfarad capacitor in parallel and perform the same test again, continue this until you see no change up or down in the meter, at this point you have achieved a power factor balance for the house, it will change if you suddenly unplug a large appliance or plug in a large appliance. But it should give you an idea on how to reduce your electricity bills a bit.

Wayne
Wayne  ;D ;D

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Re: Electrical Power Saving Devices
« Reply #1 on: June 19, 2008, 10:23:13 AM »
Wayne, since you have more electrical knowledge then me, (a do it meselfer), explain how 2 wire dirty power works. I have never found 220 on the hot leg to ground, but apparently made up on the return, since the test meter says so?

BTW, the street lights in this subdivision are on the hot leg to earth ground, (not the return leg). I guess they figure it cost less that way?? Also, the return leg is twisted bare cable in this whole area.

I have one of those devises on my AC and cuts the turn of the electric meter wheel by half+. I\'ve timed it a number of times over the last couple of years. There\'s a switch to turn it off and on like a light.

This one can not be opened since it\'s full of black epoxy. Not a bad idea to cover a persons knowledge.  ;D
B-Ray

Offline coutts00

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Re: Electrical Power Saving Devices
« Reply #2 on: June 19, 2008, 11:50:33 AM »
In the US, and Australia the only two countries of which I have knowledge, house power is delivered as single phase, in the US its single phase 110 -120v in Australia its 240v +10 -20, so it could be upto 250v or low as 220v. Depending on your load, the power is delivered as either a 2 wire or 3 wire, i.e. 2 wire single phase 110v or 3 wire (2 single phases sharing a common return). Now I could be completely wrong here as most of my experience is low voltage applications, it has been explained to me that here the common or neutral is also tied to ground.

In a computer environment we like a common ground, with all computers sharing the same ground potential. Here is a snippet from Wikipedia for your reference.

http://en.wikipedia.org/wiki/Ground_(electricity)

AC power wiring installations

In a mains electricity (AC power) wiring installation, the ground is a wire with an electrical connection to earth. By connecting the cases of electrical equipment to earth, any insulation failure will result in current flowing to ground that would otherwise energize the case of the equipment. A proper bonding to earth will result in the circuit overcurrent protection operating to de-energize the faulty circuit. By bonding (interconnecting) all exposed non-current carrying metal objects together, any fault currents in the system will not produce dangerous voltages which could cause electric shock.

The power ground grounding wire is (directly or indirectly) connected to one or more earth electrodes. These may be located locally, be far away in the suppliers network or in many cases both. This grounding wire is usually but not always connected to the neutral wire at some point and they may even share a cable for part of the system under some conditions. The ground wire is also usually bonded to pipework to keep it at the same potential as the electrical ground during a fault. Water supply pipes often used to be used as ground electrodes but this was banned in some countries when plastic pipe such as PVC became popular. This type of ground applies to radio antennas and to lightning protection systems.

A power ground serves to provide a return path for fault currents and therefore allows the fuse or breaker to disconnect the circuit. The power ground is also often bonded to the house\'s incoming pipework, and pipes and cables entering the bathroom are sometimes cross-bonded. This is done to try to reduce the voltage between objects that can be touched simultaneously. Filters also connect to the power ground, but this is mainly to stop the power ground carrying noise into the systems which the filters protect, rather than as a direct use of the power ground.

Permanently installed electrical equipment usually also has permanently connected grounding conductors. Portable electrical devices with metal cases may have them connected to earth ground by a pin in the interconnecting plug. (see Domestic AC power plugs and sockets). The size of power ground conductors is usually regulated by local or national wiring regulations.

And if all that did not confuse you try reading this.

http://en.wikipedia.org/wiki/Earthing_system

As far as I know, but have found it different in different parts of the Philippines, i.e. little or no standardization, in places where there was a US base, the power system mirrors that of the US and in some cases 110v is available, in other locations the transformer neutral is wired to ground and in other cases it is not. In my house we have a common ground for all outlets, even the ones that have only 2 poles, the metal case in the wall is still earthed in case of a short.

The long and the short of it, you should have an earth in the house tied to a copper or gal pipe going at least 8ft into the ground and a heavy duty 12 gauge or better wire tied to it, that wire is tied to a bus and all other ground wires are tied to the bus or bus bar. So when having this common ground, you use it as a reference point for power. Measure from the hot wire to ground, you should have 220v if you have 110v, tie the neutral wire to the ground wire and check again, you should now have 220v from hot to ground. And your neutral wire should have 0v from it to ground. When the electrician came here to do the wiring, he was going to wire it up the way he normally does it, but after showing him how he could hurt himself and why it should be done the way I do it, he now does all his installations this way.

Disclaimer. I am not an electrician or electrical engineer, do not try this at home. I am in no way responsible for what results you get or if you get a jolt out of it. It is only my recommendation, you should print this information and show it to a local electrician to see if he verifies its info. Let him take the chances.

Wayne
Wayne  ;D ;D

Offline dylanaz

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Re: Electrical Power Saving Devices
« Reply #3 on: September 30, 2008, 02:34:17 AM »
start with a 10 microfarad 475 volt AC Capacitor, do a baseline test, and record your power meter for a day or two with a normal load, then plug it in and watch your power meter for a day or two, recording the same information. With the same load, did the meter spin faster or slower, if it went faster, reduce the capacitor to a 4.7 microfarad one, if slower try adding another 4.7 microfarad capacitor in parallel and perform the same test again, continue this until you see no change up or down in the meter, at this point you have achieved a power factor balance for the house, it will change if you suddenly unplug a large appliance or plug in a large appliance. But it should give you an idea on how to reduce your electricity bills a bit.

Nice ! Wow

Got any diagram laying around just to picture this in my head?


Thanks!
I have seen so much conflict while in the Philippines - amazingly 99% of it was merely online computer experiences :D

Offline tropicalpenpals

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Re: Electrical Power Saving Devices
« Reply #4 on: December 29, 2008, 08:56:09 PM »
I had noticed a posting on the list about power saving devices that plug into an outlet and slow the spin of the meter. A buddy who lives next door swears by these devices and has 2 of them, well we took one apart, it is comprised of a low farad high voltage AC Capacitor and a circuit for driving some LEDs.

In your average house you have 3 types of loads, Inductive, Resistive and Capacitive Loads.

  • RESISTIVE LOAD  (heaters and incandescent lights) The voltage and current peaks coincide and are therefore in phase and the power factor is in unity.
  • INDUCTIVE LOAD  (Motors and transformers) With an inductive load the current waveform is lagging behind the voltage waveform, therefore, the voltage peaks and current peaks are not in phase.
  • CAPACITIVE LOAD (Capacitors, wiring, cable) The capacitive load has a current waveform which is leading the voltage waveform, therefore the voltage peaks and current peaks are not in phase.

In the delivery of power a term called Power Factor comes into play. Power Factor is usually referred to as a number between 0 and 1. With a Resistive Load such as an incandescent lamp or an electric stove element, the power factor is 1 and all is good in the world. With an Inductive Load  such as a Ref, Fan or Aircon there is usually a drop in the Power Factor, sometimes as low as .45 but normally close to .70, this is not good and actually increases the wattage consumed. For a Capacitive Load such as a PC, TV anything using an electronic Power Supply including your CFL\'s the normal Power Factor is .85. With a power factor less than 1, devices convert some of their power into heat and the resultant energy is lost.

Enter the power factor correcting capacitor, when the Power capacitor is placed in parallel with the AC line it changes the power factor of the circuit and your devices run cooler, consume less power and cost less to run. It has been argued and proven in some cases that Power utilities actually charge you more for your power if you facility is sufficiently out of balance with respect to the power factor.

If you consider your AC for a minute, it has 2 motors, one for the compressor / condenser and one for the evaporator / fan unit, if either of these is running hot the unit has to overcome the internal heat load as well as the room heat load to cool, so the unit tends to run more often. In most window systems the thermostat is inside the unit, if the unit heats up it will affect the thermostat and the unit may come on unnecessarily. By bringing the Power Factor as close to 1 as possible the unit runs cooler and turns on only when needed to cool the room.

This is the same for your ref and your freezer. Those of us recently from the US are aware of Energy Star Appliances, these devices have the Power Correcting Capacitors already installed to make the motors produce less heat, and consume less power therefore they are more efficient. If you have a buildup of Ice in your freezer walls the device has to work harder to overcome the ice buildup to cool the food. If you look back at our Dome Building thread, heat flows from warmest to coolest trying to reach a point of equilibrium, so in the freezer, the warm food expels its heat to the cold walls of the freezer compartment, where the heat is taken away to the outside of the unit, if there is an ice buildup, the heat can\'t escape as quickly and the freezer works harder trying to bring down the temp of the food to reach equilibrium, i.e. frozen food. Enter Frost Free Freezers, a common device in Western Countries, it is uncommon here and most freezers have to be defrosted frequently to deal with the humid air that enters when the door is opened, and stays to form frost and then ice inside the unit.

So getting back to the power saver devices, as I mentioned they are just big capacitors. The capacitors themselves could be purchased for 200p not the 5000 - 7000 asked for by vendors. As to whether they actually work will depend on the overall power factor of the combined electrical load where you live and how much the power factor needs to be adjusted. Some are too small and improve your power bill a small amount, some are too large and actually increase your power factor and hence your load costing you more money. I would recommend building your own, start with a 10 microfarad 475 volt AC Capacitor, do a baseline test, and record your power meter for a day or two with a normal load, then plug it in and watch your power meter for a day or two, recording the same information. With the same load, did the meter spin faster or slower, if it went faster, reduce the capacitor to a 4.7 microfarad one, if slower try adding another 4.7 microfarad capacitor in parallel and perform the same test again, continue this until you see no change up or down in the meter, at this point you have achieved a power factor balance for the house, it will change if you suddenly unplug a large appliance or plug in a large appliance. But it should give you an idea on how to reduce your electricity bills a bit.

Wayne

You will commonly find this sort of equipment on a larger scale with things like lift motors where invertor motors are added. How much would it save on a small scale is hard to say like you state depends on what you are using.

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Re: Electrical Power Saving Devices
« Reply #5 on: December 30, 2008, 11:51:56 AM »
Good golly miss molly, so much engineering information that floats WAY over my head, but interesting! Just MAYBE I can pickup a \"BIT\" from ya\'ll\'s efforts?  ;D

One compositor is all that\'s needed to reduce the draw, (meter spin), of an AC or Refer? I\'ll need to reread to see if it\'s inline or parallel?

My refer knowledge is some 50 years old after taking a 3 months course and working the field for a few years. but no home units, mostly belt driven units and roof top AC.

Just a funny thing I remember from back then. I and my boss went to a doctors office with an AC problem. We were on the roof about 30 minutes and everything working. My boss presented the bill and the doc came UNGLUED!! My boss just said, 10% for what we did and 90% for what we know, JUST LIKE YOU! End of the story.  ;D

Offline coutts00

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Re: Electrical Power Saving Devices
« Reply #6 on: January 09, 2009, 12:20:01 AM »
Put the capacitor legs parallel to the power, one to common and one to Neutral, make sure its turned of when you do it, or you will be singing you light up my life to the tune of 220v.

Wayne
Wayne  ;D ;D

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Re: Electrical Power Saving Devices
« Reply #7 on: January 09, 2009, 11:43:29 AM »
Thank\'s Wayne!

Now, with the saver I\'ve been using for years and a ground to the cable TV line and working for years has presented an TV cable internet problem, since hooking to cable internet and working OK for many months.

Taking the devise ground to a normal grounding and the devise doesn\'t work!

WHAT the ............... is going on?
B-Ray

Put the capacitor legs parallel to the power, one to common and one to Neutral, make sure its turned of when you do it, or you will be singing you light up my life to the tune of 220v.

Wayne

Offline My Freedom

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Re: Electrical Power Saving Devices
« Reply #8 on: February 11, 2009, 08:08:34 AM »
great thread I\'ve been looking for something like this for a while ;D