Expert Interpretation: Key Parameters of BLDC Motors and Common Traps of False Labeling

Hey, all the purchasing engineers and product managers, today let's talk about the most headache-inducing issue when selecting BLDC motors - how to judge the true performance of the motor when faced with a bunch of parameters provided by the supplier? Which indicators are most likely to "fall into traps"? Let me use my years of experience to help you sort out your thoughts.

First of all, the three most important core indicators are: torque constant (Kt), back electromotive force constant (Ke), and motor efficiency curve. You, the smart one, must know that Kt and Ke should have equal values in an ideal state. If the two values given by the supplier differ greatly, um... It is suggested that you remain vigilant. This is like buying shoes. If the sizes of the left and right feet are not the same, can they be comfortable to wear?

When it comes to the parameters that are most likely to be "inflated", the efficiency value definitely ranks among the top. Some suppliers particularly like to claim "maximum efficiency over 95%", but this might just be a theoretical value. The truly reliable approach is to ask the other party to provide a complete efficiency curve graph, with a focus on the efficiency performance within your actual working speed range. Remember, a motor that is 90% efficient at 3000 RPM and only 70% at 8000 RPM is not a good choice for high-speed applications.

No-load rotational speed and no-load current are also major areas of concern. I once came across a motor with a nominal no-load speed of 12,000 RPM, but in actual measurement, it could only reach 10,000 RPM under standard voltage. It was later discovered that it was the "ideal value" measured under specific voltage and temperature conditions. Be sure to ask clearly about the test conditions. It would be best if you could provide test data or videos.

There is also the insulation grade. This seemingly insignificant parameter is actually very crucial. If your product is to be used in high-temperature environments, such as the motor of a range hood, at least B-class insulation (130℃) or above should be selected. However, some suppliers may be vague and only say "high-temperature resistant". At this point, you should ask one more question: What is the specific insulation grade?

Here's a practical tip for you: Ask the supplier to provide a third-party test report, or take samples yourself for testing. After all, data can lie, but actual performance cannot. Rather than trusting fancy parameter tables, it's better to trust your own test results.

Purchasing BLDC motors is like finding a partner. Technical parameters are like a resume, while real performance is like a person's character. Taicot is committed to providing one-stop services for BLDC motors. Welcome to consult! Email: info@tecote.com