Single chip microcomputer STM32L151CCU6

Photocoupler

I recently tested a Yaskawa Σ5 servo motor (rated voltage: 200V, 400W, 3000 RPM) using a multimeter and got a reading of 300V. I also used the Yanzhao JD194E multi-function transmitter, which showed over 2800 volts—wait, that doesn’t make sense. Was it a mistake? Or is there something I'm missing here? The question is: when the motor reaches its rated speed, should the voltage be exactly 200V? Let’s break down some key points about servo motor voltage: 1. Is it a DC or AC servo motor? This makes a big difference in how voltage behaves. 2. At high speeds, the voltage is generally proportional to the speed. 3. At lower speeds, the voltage may drop below the speed-related value. 4. Even at zero speed, the voltage isn't necessarily zero—especially if torque is being applied. 5. In short, the voltage varies with the motor's speed. 6. The formula for voltage is: Voltage = Back EMF + Armature Voltage Drop. So, what happens when the motor is at zero speed? When the motor is not moving but still providing the rated torque, the voltage will be equal to the rated current multiplied by the armature resistance. That means even at rest, there's still a measurable voltage, depending on the load. It’s important to understand how these factors interact, especially when working with high-voltage systems like industrial servos. If you're getting unexpected readings, double-check your testing setup and ensure you're measuring the right parameters. Sometimes, interference or incorrect connections can lead to misleading results.