Voltage optimizers

Confucius

EU standard voltage is 230  /- 10%

In practice they still use 220v and we use 240v

My (German made) dishwasher, washing machine, tumble dryer, f/freezer have labels denoting 230-240v, for what it's worth.

Sonic67

Our voltage is claimed to be 240v. In practice due to resistance there will be some resistance in the wires so it might be a bit below that. The supply might also have the voltage dropped a little at peak times to make the power go further. You might notice the old type light bulbs dim slightly. Later the voltage will be picked up again. In the past electric clocks would run slightly slow then later slightly fast. On average you get the supply you pay for.

degsod

The voltage had nothing to do with how fast or slow the old style electric clocks ran it was the frequency which in the uk is 50hz. At peak times the frequency would be reduced which would slow the clocks down at at off peak it would be increased which made them run faster. Over a 24 hour period it would balance out. On modern clocks which run off DC and use a crystal oscillator as the time reference the mains frequency does not matter.

Trollslayer

Correct, they used what is called a 'shaded pole synchronous motor'.

Sonic67

You sure? I always thought it was the voltage that was altered.

Utility frequency - Wikipedia, the free encyclopedia

appliances may not operate efficiently or even safely if used on anything other than the intended frequency.

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

A brownout is an intentional or unintentional drop in voltage in an electrical power supply system. Intentional brownouts are used for load reduction in an emergency.[1] The reduction lasts for minutes or hours, as opposed to short-term voltage sag (or dip). The term brownout comes from the dimming experienced by lighting when the voltage sags. A voltage reduction may be an effect of disruption of an electrical grid, or may occasionally be imposed in an effort to reduce load and prevent a power outage, known as a blackout.[2]

degsod

Yep am sure check out your first link about utility frequency and about two thirds of the way down under stability:-
Stability[edit]
Long-term stability and clock synchronization[edit]
Regulation of power system frequency for timekeeping accuracy was not commonplace until after 1926 and Laurens Hammond's invention of the electric clock driven by a synchronous motor. During the 1920s, Hammond gave away hundreds of such clocks to power station owners in the U.S. and Canada as incentive to maintain a steady 60-cycle frequency, thus rendering his inexpensive clock uniquely practical in any business or home in North America. Developed in 1933, The Hammond Organ uses a synchronous AC clock motor to maintain perfect pitch, based on power-line frequency stability.
Today, AC-power network operators regulate the daily average frequency so that clocks stay within a few seconds of correct time. In practice the nominal frequency is raised or lowered by a specific percentage to maintain synchronization

blankscreen

I've not read the above, but several years back i was asked to become a UK agent for these tyoe of units. All was going well until it was realised in the UK we are charged per kilowatt. So yes you would use less power in reality but not see the savings made from less energy used. The power company got the benifit.

What they can do is reduce wear on electric motors that are run for long periods, take a coveyor belt motor as example, normally run at full power loaded or not. The unit i was dealing with sensed the load, and if not or partly loaded would chop the AC sign wave accordingly, reducing heat.

Imaging a canal boat engine, if you ever listen to a 'phutt' then you get several revolutions as the big flywheel spins up, until it slows down then another 'phutt' making for better economy as your not burning fuel every cycle and using the enegy stored in the flywheel.

blankscreen

I should add, it will be of little benifit in a home, where they score is saving motor wear, that saves down time and labour.

They incorporate soft start, which inturn reduces wear on the motors, and subsequently anything it drives

Used to be the motors bought in bulk were so cheap, directors and governors not enlightenned you could not get buisnesses interested, but attutudes have gradually changed over recent years.

blankscreen

When the devices were demonstrated thevrep had an electric motor jigged and linked via an amp meter, wuth a switch to bypass the controller.

it had a platform that held a glass of water to easier show vibration, he turned on the motor in standard mode, the initial start cause quit a jolt. and when uo to speed the water was like a rough sea. With the inverter connected there was only a small jolt then smoothly up to speed hardly a ripple.

The Amp meter showed a marked drop in free running current using the inverter, what you could not see was the redused inrush current that occures with any device when initially switched on, was arrested. Here and motir stall current plays a part, especially if stopped and started many times current drawn is greatly reduced.

Traditionalky to reduce failures bigger motors than needed were used, with inverter companies can buy less robust motors, because they are not working anywhere near so hard when starting up or working in reduced loading.

If i were to sell it today i would not mention anything about saving in the electric bill - vaunted as a main USP, savings in that way will be very small due to billing by KWt in the UK, concentrate on the down time savings and cheaper motors, which even if billed by current drawn any bill savings would be dwarfed.by oroduction savings.

Alan