" />
" />
" />
" />
" />
" />
" />
" />
" />
" />
" />
A Simple, Managed Process
Free Site Assessment
Power Quality Analysis
Energy Savings Proposal
Commissioning of Products
Free Verification Testing
Years of Energy Savings
Power Quality Analysis
Energy Savings Proposal
Commissioning of Products
Free Verification Testing
Years of Energy Savings
Energy Savings - Advanced
On what load types can The Ark generate savings?
The Ark can generate savings across a wide variety of load types, including;
|
What happens to electric motors when they are supplied with high voltage levels?
Motors are particularly susceptible to over-voltage. While it depends where they are manufactured, the majority of 3-phase motors in Australia are designed to operate optimally at 380-390V. The average supply voltage in Australia is significantly higher than this (approximately 415V). Some of the problems this excess voltage creates for 3-phase motors include;
|
How does The Ark create savings with electric motors?
|
As we know, Power (kW) is equal to the Voltage (V) multiplied by the Current (i), kW = V x I. Power into a 3-phase motor (kW in) is equal to the power out (kW out) plus system losses (heat and vibration). A motor running on higher voltage than required will have increased copper and iron losses for a similar power output, as well as poorer power factor. Hence the electricity consumed (kW in) significantly increases with an increase in voltage beyond a motor’s optimum capacity. With an Ark installation, the internal losses and the stress on motors is significantly reduced. An Ark installation enables motors and equipment on-site to operate within their optimal (and design specified) voltage range, while also improving power factor, 3-phase voltage balancing and reducing harmonic distortions. The net effect is that motors operate with greater efficiency. There is a significant reduction in internal losses and hence a net reduction in power usage for the same motor output. There is no effect on the speed of the motor as this is determined by the number of poles on the motor and the frequency of the electricity supply. By providing voltage within the motors design specified voltage range, there is no reduction in torque. As a result, The Ark provides very good savings on loads with 3-phase motors. Hence, mechanical services loads, such as air-conditioning, ventilation, heating, refrigeration and general plant and machinery provide attractive ROI’s when tailoring an Ark solution for a site. |
What about Ohms Law?
|
Since Power = Current x Voltage (P = I x V), the common electrical paradigm and traditional teaching is that if you reduce voltage, the current will increase proportionally. In order for the current and voltage to be inversely proportional, this interpretation of the formula assumes that electrical loads have constant power i.e. regardless of changes in voltage and current, a 2kW motor will always use 2kW. In real life, this is not the case and the formula simply means that the power being drawn is the product of voltage and current. Power into a 3-phase motor (kW in) is equal to the power out (kW out) plus system losses (heat and vibration). In a theoretical sense, there are no system losses. However, in real-world applications, we know that this is not the case. Anyone who has observed the heat, vibration and noise of a motor is aware that this is a dissipation of energy that is not being used to create output from the motor. The introduction of these system losses as a result of poor electricity quality, outside of the controlled environment of Ohms Law theory, is what changes the practical interpretation of the law in this instance. The nameplate power of machinery will be delivered at any voltage within the statutory range of 216-253V in Australia. However, when a motor receives voltage above its optimum and design specified level, additional energy is used for no improvement in performance. It will continue to deliver its rated output, but will use more energy to do so as the core is driven into saturation and iron and copper losses increase. Energy is dissipated in the form of heat and vibration and more energy is consumed as a result. By optimising the voltage to the most efficient operating point for motors and equipment (and also improving the power factor, improving 3-phase voltage balancing and reducing harmonic distortions) The Ark significantly reduces the losses that are created by poor electricity quality, and consequently reduces the energy consumed by the motor while delivering the same output. Further, it is known that Voltage (V) = Current (I) x Resistance (R). As P = I x V (and I = V/R), by substitution P = V2/R. If we assume that the resistance is constant, it follows within Ohms Law theory that with a reduction in voltage, the power will reduce as the square of the voltage. This is what actually happens with most electrical equipment in a practical situation. Accordingly, reducing the voltage from the average supply level in Australia of 240V, by 8%, on a 20Ω load, will result in a reduction in the power from 2.880 kW to 2.42 kW. This application of Ohm’s Law theory provides for a 16% saving in energy. This level of savings from The Ark on 3-phase motors is very clearly demonstrated in practical applications. |
Will my electric motors be affected in any adverse way by The Ark?
|
No. Independent tests have been carried out by the University of Newcastle in response to initial electrical engineering concerns that reducing the voltage delivered to electric motors will cause the motors to heat up. The results of this test and the practical application of The Ark in clients premises over many years clearly proves that The Ark does not have this effect. |
How does The Ark compare to VSD’s or VFD’s on motors?
|
An Ark installation on a load with AC Motors will deliver comparable energy savings to a typical VSD (Variable Speed Drive) or VFD (Variable Frequency Drive) installation. If a VSD or VFD is already installed, an Ark installation will still generate savings, however they will be less than would be achieved without the VSD or VFD installed. Due to The Ark’s ability to improve the quality of power supplied to the load (by optimising the voltage and improving the power factor, 3-phase voltage balancing and harmonics), the lifespan of any VSD’s or VFD’s already installed will be extended as a result of an Ark installation - particularly due to the susceptibility of VSD’s and VFD’s to the stresses associated with over-voltage. Additionally, VSD’s and VFD’s are renown for the harmonic distortions that they create. Due to the harmful effects of harmonic distortions on sensitive equipment, The Ark’s ability to reduce harmonics will help mitigate the damaging effects of VSD’s and VFD’s. |
What are the consequences of harmonic distortions?
|
Harmonics can be likened to pollution within your power supply. The consequences of excessive harmonic levels include overheating of distribution boards, de-rating of circuit breakers, degradation of power factor correction equipment, overheating in cables (increasing the risk of damage to cables and electrical infrastructure and potentially the risk of fire), de-rating the output of generators, inefficiencies in the operation of electrical motors and wasted energy consumption. Sources of harmonic distortions can be electronic loads, electronic ballast fluorescent lights, computers, UPS units, Variable Speed Drives (VSD’s), Variable Frequency Drives (VFD's) etc. Due to the increasing proportion of electronic devices and ‘non-linear’ loads within premises, the occurrence of the problems resulting from harmonic distortions is also increasing. |
What effect does The Ark have on Harmonics?
|
The Ark does not create harmonics. Further, whilst The Ark is not a dedicated harmonics filter, it is able to reduce harmonic distortions (both voltage and current harmonics) as a result of the built in tertiary winding and thus helps address the problems associated with high harmonic levels. Losses due to unwanted harmonics increases with increases in frequency. The Ark gives notable energy reduction at lower frequencies with increasing reductions as frequency increases. |
What are the consequences of 3-phase voltage imbalance on motors?
| The effect of 3-phase voltage imbalance is somewhat analogous to a spinning wheel. If the wheel is not completely balanced, the force required to maintain the spinning motion is higher than for a balanced wheel. Hence, in practical terms, 3-phase voltage imbalance can result in significant energy waste and heating of motors and wiring. Maintenance requirements also increase as motors run less efficiently. |
What effect does The Ark have on 3-phase voltage imbalance?
|
The Ark is able to improve the voltage balance between the 3-phases. Within The Ark, as each phase is star connected to each other and due to the manner of interconnection between the two coils, a level of voltage balance between each phase is provided at the unit’s output. The effect is a more suitable supply to the connected load, providing increased efficiency in the operation of loads - in particular rotating loads (e.g. 3 phase synchronous motors). |
What are the consequences of poor power factor?
|
Power Factor is essentially a measure of how effective electrical power is being used by a system. It is represented by a numerical value between 0 and 1, equal to the ratio of reactive power to active power. The higher the value, the more efficient the system. A system with poor power factor requires the energy retailers to supply more power in order for end-use equipment and appliances to operate. The requirement of this additional power can result in excessive heating of equipment and electrical infrastructure, additional maintenance costs and the potential for fires in extreme situations. In regions where customers are charged on the basis of kilovolt amps (kVA), a financial penalty is effectively charged for poor power factor. |
What effect does The Ark have on power factor?
| The Ark is not a dedicated power factor correction unit, however it typically improves power factor in the order of 0.01 to 0.08. This occurs by combining the action of Coils A and B (within The Ark) to compensate with reactive energy as required when phase current tends to lag excessively behind voltage. This is achieved via the unique combination of physical location and electrical connection of Coil A in series and Coil B in parallel with the load. Coil A provides energy to the load for the most part. However, as a fundamental of alternating current principles there are ‘gaps’ in Coil A’s supply. Coil B compensates for these ‘gaps’ by way of the unique interconnection of Coils A and B to maintain or improve Power Factor. |
What effect does The Ark have on different lighting types?
The Ark is able to generate high levels of savings on lighting loads, particularly the following types;
Optimising the voltage to the correct level will improve the efficiency of all types of lighting, including those with resistive or magnetic ballasts. If other energy efficient lighting devices have already been installed, The Ark can generally still create further savings, however the savings will be less than without the other energy efficient device. As well as creating energy savings, optimising the voltage provides significant improvements in the lifespan of lights. Incandescent lighting is particularly susceptible to high voltage levels and a 5% increase in voltage decreases the life of lamps by up to 47%. For fluorescent lamps, an increase in voltage of 10% decreases lamp life by up to 15%. Minimising lamp change frequency by optimising voltage creates significant cost savings in labour and replacement consumables. |
How does this technology compare to other energy efficiency measures for lighting?
|
Fixed dimming units can only be used on some lighting loads. This means that energy saving can only be achieved on the portion of your total power bill relating to this suitable lighting, which in most cases represents only 20-25% of your electricity consumption. Fixed dimmers on lighting generally run at full voltage for 5-10 minutes on start up, so lights that are only on for short periods of time or are used intermittingly will see reduced savings. The Ark works anytime that lights are switched on. Some lighting control systems mechanically drop the voltage a pre-set amount. This type of lighting control is not compatible with The Ark, as the voltage reduction from the action of both devices would reduce the voltage too low for the effective operation of the lighting. Other energy saving measures on lighting use electronic controllers or electronic ballasts. Because these devices are responsible for generating high levels of harmonic distortions, The Ark can improve the efficiency of these loads further by helping filter the harmonics and thus helping provide protection for sensitive equipment. Optimising voltage with The Ark can reduce the need for the investment in energy efficient lighting devices, as lighting loads are made significantly more efficient by the operation of The Ark. Savings can be provided with one product across the entire premise, encompassing not only the whole range of lighting, but also general power and mechanical services loads. |
Does The Ark work for resistive devices?
|
Typically, a resistive device that is specifically designed to produce constant power (including some lighting and ovens/ electrical kiln heating) will result in a lower level of savings. For this type of equipment, although the voltage supply is reduced, the device is rated so that it will draw more current to provide constant power. If we are placing an Ark on a general light and power load, it will usually contain a mixture of electrical load types, and savings are aggregated across all the equipment. The effect of any resistive devices upon the energy savings is factored into your projected financial payback during the site assessment stage. |