"electricity Saver" Fraud

[lingling]

So I went to Suan Lum Night Bazaar earlier today. A couple of shops were selling devices they claimed would slow down the electricity meter (labelled "energy saving unit").

The booths selling them had what appeared to be a standard electricity meter like the one you will have outside the house or apartment and were willing to demonstrate the devices using that meter. When they plugged it in, the meter slowed down.

This got me curious - would this device actually interfere with the meter by sending out control pulses (thus defrauding the electricity company), or were these people defrauding their buyers with a fake device?

I just had to buy one to find out...

There were four different "sizes" available for different prices, so I settled for the smallest "15kW" (did they mean kWh?) version: B400.

Once I got home, I opened it up.

Inside is:

1) a fuse (how nice of them)

2) a 6µF capacitor, rated for up to 250V AC (so a spike and that one will be shorted, thank's for spending the extra 50 satang for the fuse )

3) a 10mm red LED (to indicate that it is plugged in)

4) a 150kΩ resistor connected in serial with the LED (to make the LED not fry)

...making the total component value about B15 including box etc.

...so... as we already knew, this thing will not "save" any electricity, nor will it slow down a meter unless the same meter is rigged with an inductive load with a size matching the capacitor (so the capacitor takes out the inductive load). Instead, in a normal setting this one will of course use electricity so anyone who think they are "saving" on their electricity bill with one of these is of course putting a few baht extra onto their bill by having it plugged in.

External and internal photos below:

Edited April 9, 2006 by lingling

[stumonster]

I presume they intend to 'save' power by adjusting the power factor of the load with the cap - huge.

what did they have plugged in for the demo setup?

one method I have heard of was done by a watchmaker , he bored about a 1/4 mill hole in the back of the meter and glued a horsehair in there so it touched the disc to produce a bit of drag.

[GuestHouse]

The device works by creating a phase difference between the current and the voltage.

This phase lag interferes with the meter's measuring circuit, it will also intefere with the operation of ellectronic and electical equipment in the house.

The device can itself heat and catch fire.

I'd stay clear of it if I were you.

[Prakanong2005]

Did people not use large magnets in the UK years ago to slow the wheel down?

People also used to put the gas meter on backwards as well did they not?

[cobra]

The device works by creating a phase difference between the current and the voltage ...

Yes, another variation that negates having to actually tamper with the utility's metering,

The PF is degraded due to inductive reactance created by motors and other inductive devices, (refrig compressors, washers, etc.),

By adding some capacitive reactance to correct the PF towards unity helps, in home applications the savings isn't that appreciable, hence there probably wasn't a big line queued at the stall waiting to buy one.

Also definitely advise not tapering with the utility's meter, (magnets, drag induction, pulse interference, etc), they've seen every trick in the book, you'll just end up with permanent disconnection, reading by candle light)

[sting01]

The device works by creating a phase difference between the current and the voltage ...

Yes, another variation that negates having to actually tamper with the utility's metering,

The PF is degraded due to inductive reactance created by motors and other inductive devices, (refrig compressors, washers, etc.),

By adding some capacitive reactance to correct the PF towards unity helps, in home applications the savings isn't that appreciable, hence there probably wasn't a big line queued at the stall waiting to buy one.

Also definitely advise not tapering with the utility's meter, (magnets, drag induction, pulse interference, etc), they've seen every trick in the book, you'll just end up with permanent disconnection, reading by candle light)

Tampering with utility meter, nothing more easy, nothing more dangerous.

If caught, or suspected, you will simply return to the stone age.

Easy to do, because, there is a screw that is used to check the speed of the main wheel. So, just have to make it slow a bit. The main problem is to know which screw and where it's located. It's various from brand and models, and totally illegal.

Other system, are simply technically dangerous (heat, explode) and as well totally illegal.

To reduce your bill, you can use wind power, sun power ....

[Tywais]

Some information on Power Factor Correction. 6uF? Hardly sufficient for 15kW if it is all inductive. I have built a PFC for a system (fully inductive) and it can reduce the effective current significantly. In my case needed about 150uF for a 900W system. The capacitor has to be very low ESR to handle the current and they get expensive at these ratings and specs. Chances are items like refrigerators rated Green (energy efficient) already have one in it.

http://home.earthlink.net/~jimlux/hv/pfc.htm