You Can’t Watch Television on a Washing Machine!
Tuesday, February 26th, 2013
Today, we are all familiar with the energy rating labels for domestic appliances, rating these products for efficiency from A+++ to G. This scheme was introduced in 1992 as part of EU Directive 92/75/EC, and over the last 20years the scope has been expanded and now Minimum Efficiency Performance Standards (MEPS) are set for refrigeration, washing machines, dishwashers, ovens, water heaters, air conditioners, light bulbs, TV’s and cars.
Gradually EU legislation is expanding the scope and new products groups are added as Lots. In 2009, Lot 11 lead to EU Regulation 640/2009 governing the energy efficiency of electric motors, and now the EU is consulting stakeholders regarding Lots 28, 29, 30, 31, all related to Motor Control.
Lot 28: Pumps and controls for private and public waste water and for fluids with high solid content
Lot 29: Pumps and controls for private and public swimming pools, ponds, fountains and aquariums,
Lot 30: Products in motor systems outside the scope of the Regulation 640/2009 on electric motors, such as special purpose inverter duty motors (asynchronous servo motors), permanent magnet motors, motors cooled by their load (fans), including motors and products such as soft starters, torque or variable speed drives.
Lot 31: Products in motor systems outside of the scope of Lot 30 and the Regulation 640/2009 on electric motors, in particular compressors, including small compressors, and their possible drives.
There is no doubt that EU lead initiatives on product efficiency have had a positive effect on product design and consumer attitudes, but the product lead approach used for domestic appliances may not be applicable to Motor Control equipment.
When you purchase a refrigerator, TV or washing machine, it clearly can only be used for that single specific task, you can try to watch your favourite TV show on the washing machine, but this isn’t what is meant by a ‘Soap Opera’. So, with domestic products the only way to drive manufacturers and consumers towards reducing energy consumption is too highlight the best and worst performing products.
Motor Control equipment is somewhat different, when you purchase a motor, variable speed drive or soft start it can be used for an endless range of tasks, pumping, lifting, pulling, blowing, rotating, crushing, cooling, compressing etc, etc. Each application has its own technical challenges and different energy consumption profiles, and therefore each application requires a different approach. In nearly all cases the energy efficiency of the process is determined by the correct design of the system, and not by the tiny differences in efficiency between brands of variable speed drive or soft start.
The proposed legislation will allow users to compare Product A against Product B, but it won’t ensure that either product is the suitable one for that application. The highest efficiency variable speed drive, incorrectly fitted to a fixed speed application will actually increase overall energy consumption. In this case it would be best to fit a soft starter. Rather than comparing and setting targets for the efficiency of products, legislation should adopt a systems approach where the overall energy efficiency of the process is measured and targeted.
The laws of physics state that ‘energy can neither be created nor destroyed’, and therefore all motor driven systems are merely energy conversion devices. The efficiency of these systems should be rated by comparing the energy drawn from the electrical supply against the amount of work done, everything else is wasted energy.
By applying the same product centric approach to motor control equipment as used for domestic appliances, the proposed EU legislation could merely ensure that we use energy efficient motor control products, but within systems that have very poor overall energy efficiency.
Mark Shepherd – Managing Director