Now is the time to switch over motors under 0.75 kW
Since the beginning of 2018, SEW‑EURODRIVE has offered its DRN.. series of IE3 AC motors in powers below 0.75 kW. This expands our range of powers from 0.09 kW to 225 kW. What makes our global motor so unique on the market? Our expert Vandré Luis de Castro Marques answers these and other questions.
"We are taking the costly certification procedure out of our customers' hands worldwide"
- How does SEW‑EURODRIVE's global motor manage to fulfill energy efficiency requirements worldwide?
The European Union and its declarations of conformity are the exception to the rule. In other countries, simple compliance with the applicable standards is often not sufficient. Depending on the legal regulations, extremely complex and costly certification procedures may be necessary, up to and including a plant audit.
Before SEW‑EURODRIVE can set about fulfilling local laws and regulations, we have to take a good look at and truly understand the various country-specific requirements. It is not always the case that the necessary documents, which are often quite lengthy, are available in English.
That's why it's good that SEW‑EURODRIVE has a global presence with experts in these countries who have experience working with these standards and speak the language. These employees are also very familiar with the local bureaucracy and handle all necessary business with the authorities. In India, for example, this was a great help. Because although English is an official language in India, the whole process there was extremely complex.
Our customers worldwide will see double the benefits from our global motor: Since we have taken care of the cost-intensive certification procedure, they can immediately start using our drives as a replacement for their existing drives. And the drives also reduce their energy costs significantly.
- Since the start of 2018, the DRN.. series of IE3 motors has also been available for powers below 0.75 kW, thereby covering a power range from 0.09 kW to 225 kW. What makes our global motor so unique on the market?
In contrast to other drive manufacturers, SEW‑EURODRIVE is the only one who makes it a point to ensure that all designs and options are consistently available for all sizes and all the various motor series. When you combine this diversity with the wide variety of combinations in our modular gear unit system, you get a virtually endless number of possible combinations, which allows our customers to tailor their application precisely to their requirements.
It was important to us to continue this consistency and interchangeability when we extended the DRN.. series of IE3 motors to the lower power range. In this project we even added to the number of possible combinations in our modular gear unit system.
No other manufacturer offers this level of variety. And wherever in the world you are, there is always an SEW‑EURODRIVE location nearby, where you can have your motor repaired or replaced.
That's what we're about. It's the strategy that has made us successful. And our customers along with us.
- Since January 1, 2017, energy efficiency class IE3 has been prescribed for asynchronous motors with a nominal power of 0.75 kW and higher. And now there are new energy efficiency regulations in the works which would affect motors below 0.75 kW as well. Is it a good idea for our customers to switch over to our new "small" DRN.. motors right away?
The additional costs for IE3 motors in the low power range run into the low double digits in euros. An investment would therefore pay for itself in less than a year. That depends, of course, on the application and the number of operating hours per year.
Here is a sample calculation: Assuming a 0.37 kW motor running at continuous duty in two-shift operation, the user would save about 37 euros per year with an electricity price of 0.12 euros per kilowatt hour.
That may not seem like a lot at first glance. But a plant often has hundreds of such motors in operation. In this case the energy savings will rapidly become apparent in the operating costs.
- At what age is it a good idea to completely replace a gearmotor with a new gear unit and a new DRN.. motor?
You shouldn't replace a working gearmotor just because of its age. In addition, we've had drives in the field for the past 10 years, starting with the DRP.. portfolio of motors, that already fulfilled the IE3 energy efficiency class.
On the other hand, there are thousands of new motors put into operation every day that don't even meet the IE1 energy efficiency class. This means that a discontinued motor from SEW‑EURODRIVE, despite its age, is still more efficient than some brand-new motors from other manufacturers.
What's important when purchasing a new motor is to consider the requirements of the application, the operating times and the energy costs.
"All labels relating to standards and legal regulations are found on our motors' nameplates."
- How do I know which energy efficiency class my motor currently fulfills?
All countries require the energy efficiency class to be identified. But, as is so often the case, the energy efficiency classifications are not identical worldwide. In Europe, for example, we have IE classes, while Brazil uses IR classes and China uses grades. Grade 1 is the best class and currently corresponds to our IE4.
All labels relating to standards and legal regulations are found on our motors' nameplates. This is also the case for the energy efficiency classes, which are listed multiple times on global motors: Percentages for three different capacity utilizations confirm that the motor meets the specified energy efficiency.
Some countries also require special labels with additional information. These labels look similar to the labels we know from household appliances.
- What makes a motor an IE3 motor? How does an IE3 motor differ from an IE1 of the same series? And what should the customer keep in mind when making the switch?
Essentially, AC asynchronous motors achieve higher efficiencies through optimized materials and a higher density of the active parts.
A higher density, though, can lead to differences in design. Motors of the same size may become somewhat larger and heavier. If the installation space is already tight, it may need to be expanded.
- For which applications is it a good idea to convert to IE3 or to use an IE3 motor in a new system? When is it better to use one of our IE1 motors of the DR2S.. series, which are now also available starting at 0.09 kW?
Compared to its IE3 counterpart, the DRN.., the DR2S.. weighs significantly less and always packs a bit more power. In other words, a DR2S.. of the same size offers higher power.
In applications with switching or short-term operation, motors with a higher energy efficiency class can actually have a negative effect on energy savings because of these design differences. In such cases the more compact IE1 motors, like those in the DR2S.. family, are the better choice and are therefore listed as exceptions in the global efficiency regulations.
- For which motors does the standard apply? Why not for synchronous motors?
The current energy efficiency class standards only apply to AC asynchronous motors with squirrel-cage rotors. Servomotors are not governed by these standards.
Because they are designed with permanent magnets and their own fanless cooling system, however, they are subject to significantly fewer losses than asynchronous motors. These design features result in very high efficiency up to the IE5 energy efficiency class, even if this is not identified on the nameplates.
- How can you ensure the switchover runs smoothly?
We developed the new motors so that the switchover is as smooth as possible. Aspects such as compactness, compatibility of replacements and comparable technical data were given the highest priority during the development phase.
Nevertheless, it is unavoidable that in certain cases we will have to discuss the specific design requirements with the customer in order to find an optimal solution. In such cases it is not only the length and width of the new motor that are of importance. In applications with very limited space, the new external contour can also play a role.
- What else should I keep in mind when switching to an IE3 motor? Do I have to recalibrate the inverter?
The new motors always require a new startup procedure. With SEW‑EURODRIVE frequency inverters, however, the switchover is very simple because the new technical data is already implemented in all of our tools.
The frequency inverter can be reparameterized quickly and easily by downloading the new database to a computer or having it updated by SEW‑EURODRIVE.
For new systems, the customer can select from a wide range of inverters, control technology and software from SEW‑EURODRIVE. Every motor, whether old or new, is integrated in our latest tools.
The new motors also come already prepared for the digital interfaces of the MOVI-C® family. They have an electronic nameplate that the customer can simply import. There is no need to enter the values yourself. A connected frequency inverter detects the motor automatically, eliminating the need for further parameterization.
- Are the standard-compliant energy-efficient motors also available for use in potentially explosive atmospheres?
Explosion-proof motors are increasingly subject to global energy regulations. For Europe, there are even plans to add these motors to the scope of the ErP Directive. The requirements have already been defined, but there is not yet a corresponding law.
In any case, SEW‑EURODRIVE will definitely expand its explosion-proof motors of the EDRN.. IE3 series further downward and launch models in the under 0.75 kW power class at the beginning of next year.