1. How do I know if a motor is efficient?

Electric motors are rated in IE efficiency classes according to IEC 60034-30-1. The higher the number, the more efficient the motor. IE3 or IE4 are efficient motors. All the information on the efficiency classes of motors can be found under standards & regulations.

2. Can you save energy with a frequency converter?

A frequency converter on its own does not yet save any energy - to the contrary. It adds its own 3% to 5% losses. Savings of more than 40% can be achieved in closed systems (e.g. in ventilation systems or pump circuits) by reducing the motor speed and thus also the flow of air or water instead of using a throttle. Further information can be found in fact sheet no. 25: Frequency converter (so far only in german & french).

3. How do I know if my motor has saving capacity and how much this would be?

Topmotors has gained a large amount of practical experience from over 4 000 systems in diverse sectors in industry over the last 10 years. That is why the 4-step audit method Motor-Systems-Check was developed. It helps users to measure not only the motors, but the entire motor driven system including all the components (frequency converter, motor, transmission, application, etc.) and to estimate the potential energy savings. The Motor-Systems-Check helps you to identify the largest potential savings from a variety of motors. The free software tools facilitate the systematic analysis of the entire machine park.

4. What motors can I currently use in Switzerland or in Europe? What are the legal minimum requirements?

The current legislation and the applicable minimum requirements can be found in standards & regulations.

5. Are there ways to get funding for improving the efficiency?

Yes. The information and contacts for this topic can be found under financial incentive programs.

6. Where can I learn how to properly size and efficiently operate a motor driven system?

Topmotors offers a wide range of documents with valuable information free of charge under the section Knowledge. The fact sheets (so far only in german & french) provide you with comprehensive basic knowledge on specific technologies and topics. In addition, we regularly stage events, such as workshops on alternating topics or the Motor Summit where experts present the latest findings and the participants exchange data and ideas with each other. Topmotors is also organising webinars on alternating topics. Our 6-day advanced training course in Industrial Energy Optimisation (IEO) provides participants with intensive advanced training on efficient motor driven systems in industry.

7. What are harmonics?

Ripple harmonics or harmonic waves are often referred to as harmonics. They are caused by the frequency converter due to the pulse-width modulation and have a negative impact on the efficiency of the motor and the mains power supply. Further details and more in-depth information can be found in fact sheet no. 25: Frequency converter (so far only in german & french).

8. As a manufacturer, where can I find the relevant legal requirements for my product ?

The Ecodesign regulations for motors, circulators, water pumps and fans set out in detail the conditions under which a motor must meet the requirements. You can find all the details under standards & regulations.

9. My new motor needs more power than the old one. How can that be possible?

A "new" motor (e.g. IE3) has lower losses than an "old" motor (e.g. IE1). As a result, the motor also has a lower slip and therefore its speed is about 1% to 3% higher. If, for example, the old motor on a pump or a fan is replaced 1:1 by a more efficient one, the system runs faster and thereby unnecessarily discharges more air or water. This means it consumes more electric power. This additional consumption can be the same or even greater than the lower consumption due to the improved efficiency of the motor. Therefore, the new nominal speed must be adapted to the old speed. More information on this issue can be found in fact sheet no. 25: Frequency converter (so far only in german & french).

10. Should I put a frequency converter on my old and oversized motor?

Older motors (over 10 years) are not necessarily suitable for being supplied by a frequency converter. The switching sides of the voltage occurring in frequency converters can damage the insulation of the stator windings in a short space of time. The overspeed is limited due to the mechanical properties. Additional cooling might be required at lower speeds. Further information can be found in fact sheet no. 25: Frequency converter (so far only in german & french).