AUTOMATIC VOLTAGE OPTIMIZERS
IT’S TIME TO SAVE
Voltage optimisation is a term given to the systematic controlled reduction in the voltages received by an energy consumer to reduce energy use, power demand and reactive power demand. While some voltage “optimisation” devices have a fixed voltage adjustment, others electronically regulate the voltage automatically. Voltage optimisation systems are typically installed in series with the mains electrical supply to a building, allowing all its electrical equipment to benefit from an optimised supply. Overvoltage leads to sites using more electricity than needed, and as a result incurring higher electricity bills. The overvoltage is not only costly but can also be detrimental to equipment. Excess voltage produces additional noise, heat and vibration, causing stress on internal parts, especially to motors which are vulnerable to overheating and wear out more quickly. IREM Ecostab voltage optimisation system ensures that a building only receives and pays for the voltage that it actually needs, and no more, optimizes power quality and generates energy savings. IREM Ecostab Voltage Optimisers are available in power rating from 8 to 2800 kVA, singlephase and three-phase versions.
VOLTAGE OPTIMISATION (VO):
The average voltage supply from many national grids around the world is often higher than the ideal operating voltage for most electrical equipment like lighting and motors. For example, a 230V linear appliance used on a 240V supply will take 4.3% more current and will consume almost 9% more electricity than at 230V. Sites fitted with a voltage optimisation system often achieve reductions in the region of 5 to 15% for energy consumption, costs and therefore carbon emissions! The first step to evaluate the profitability of installing a voltage optimiser is to monitor and know your present incoming voltage levels, the IREM
Energy Saving Meter allows you to determine this. IREM Ecostab Voltage Optimisers of “B” series are fitted with 2 digital network analysers. These multimeters display all the electrical parameters measured, voltage, current, frequency, power, power factor, THD, etc. from the input mains and at the optimiser output.
These multimeters have:
- Graphic LCD display 128x80 pixel, backlit;
- 4 keys for display and setting;
- quick and easy navigation;
- texts for measurements, settings and messages in 5 languages;
- true RMS measurements (TRMS);
- seamless data acquisition;
- high accuracy.
IREM Ecostab Voltage Optimisers of “S” series, besides the standard equipment of the “B” series, are fitted with an additional display showing the energy saving achieved by the VO. The values displayed are calculated according to the method recommended by the VDE-AR-E 2055-1 Standard.
The saving is displayed ensuring the accuracy of the metrological chain of measuring instruments.
SAVING AND RETURN ON INVESTMENT
By means of potentiometers the OPTIMAL OPERATINg VOLTAgE can be set according to the peculiar features of the connected loads. The minimum stabilised voltage is 207V.
The dwindling fossil fuel reserves, the need to reduce carbon dioxide emissions and lower availability of financial resources has spurred energy production from renewable sources and strongly boosted the development of technology for optimising (limiting) electricity consumption.
Ecostab automatic voltage optimisers are one of the solutions offered by new technologies to users.
These devices comply with the requirements of IEC 60038 for electric equipment operating tolerances and supply an operating voltage which minimises consumption without impairing performance or reducing reliability. IEC 60038 establishes that the electric equipment must be able to work correctly at an input voltage within ±10% of the nominal value, that is from 253V to 207V for singlephase devices and from 440V to 360V for three-phase devices. This is an essential feature for all electric devices because energy producers establish that the supplied voltage may vary within these limits contractually. As a consequence, if a load is supplied at a value close to the lower operating tolerance limit (-10%) also when the mains voltage assumes the higher value established by contract (+10%), the difference between 253V and 207V in absolute terms is 18%.
This power supply difference allows to:
- obtain a significant saving of energy;
- extend the working life of electric equipment. Ecostab voltage optimisers prevent devices from being powered at higher values than the rated voltage. For example, it is a known fact that the life of sodium bulbs is reduced by 50% when they are powered at a voltage 10% higher than their rated value;
- secure a significant reduction of carbon dioxide emissions. This corresponds to approximately 630 g for every saved kWh of energy.
Ecostab automatic voltage optimisers deliver a stabilised voltage which can be set to the minimum tolerance established in IEC 60038, i.e. -10% (207V). This value is guaranteed also in presence of significant mains voltage variations. Interestingly, these devices are also excellent mains voltage stabilisers.
- Standard single-phase models can deliver a variable voltage from 230V to 207V with input voltage between 207-253V range.
- Standard three-phase models can deliver a variable voltage from 360/207V to 400/230V with input voltage between 360/207V and 440/253V.
Models capable of broader input voltage variations may be built on demand. These may be needed because voltage may sometimes exceed the 10% tolerance specified in the supply contract.
Automatic voltage stabilisation is a key function that sets Ecostab voltage optimisers apart from simple autotransformers, which also reduce voltage but cannot guarantee certain savings due to the continuous voltage variations of the mains.
In order to prevent the delivered voltage from dropping excessively low as a consequence of mains fluctuations, autotransformers can never provide maximum savings. The following diagram shows three different power supply possibilities with average absorbed power and saving for an electric motor.
The area included between the red and the green lines represents the maximum saving achievable by Ecostab compared to the autotransformer economisers.