VFD Output Frequencies Explained – 50Hz, 60Hz, 400Hz and Beyond
One of the key advantages of using a variable frequency drive (VFD) is the ability to control the output frequency to a motor. But what does that really mean—and how does 50Hz differ from 400Hz? In this guide, we explain how output frequency affects motor speed, torque, and efficiency—and when you should adjust it.
⚙️ What Is VFD Output Frequency?
Output frequency refers to the number of AC cycles per second that the VFD sends to the motor. It’s measured in Hertz (Hz). The higher the frequency, the faster the motor will run—assuming voltage and load conditions allow it.
- ✅ 50Hz = standard UK/EU power supply
- ✅ 60Hz = standard North America power supply
- ✅ 400Hz = aerospace, high-speed spindles, and special applications
🔁 Frequency vs Motor Speed
Motor speed is directly related to the output frequency according to this formula:
RPM = (120 × Frequency) ÷ Number of Poles
Example: A 4-pole motor running at 50Hz will turn at approximately 1500 RPM. At 60Hz, the same motor will run at 1800 RPM.
VFDs allow you to control this frequency—and therefore your motor speed—in real time.
📊 Common Frequency Ranges in VFDs
| Frequency | Typical Use Case | Drive Example |
|---|---|---|
| 0–50Hz | General motor control (UK/EU) | Delta MS300 |
| 0–60Hz | North American motors | PowerFlex Series |
| 0–400Hz | High-speed spindles, HVAC, aerospace | ABB ACS880 |
| 400Hz+ | Custom or experimental use | Custom-configured drives only |
🚀 When Should You Use 400Hz or Higher?
Not all motors are designed to handle high frequencies. 400Hz is typically used for:
- ✈️ Aerospace ground support motors
- 🌀 High-speed compressors or spindles
- ❄️ HVAC systems requiring fast fan speeds
Ensure your motor, bearings, and load are rated for high-speed operation before exceeding standard frequencies.
⚠️ Risks of Over-Frequency Operation
- ❌ Excessive heat and insulation breakdown
- ❌ Increased mechanical wear
- ❌ Potential loss of torque
- ❌ Unstable operation if not properly tuned
Always consult the motor datasheet and use proper ramp-up/ramp-down settings when adjusting frequencies.
🧠 Related Tools & Reading
🛒 VFDs With High Output Frequency Support
- 🔹 Delta MS300 – Up to 599Hz
- 🔹 ABB ACS880 – Fully programmable frequency range
- 🔹 Allen Bradley PowerFlex Drives
📦 Why Buy From Drive Outlet Megastore?
- ✅ 3,000+ VFDs in stock with varied frequency control
- ✅ Trusted brands: ABB, Delta, Allen Bradley, Danfoss
- ✅ 2-Year warranty + next-day UK delivery
- ✅ Free calculator tools and expert support
Need help choosing the right frequency range? Contact our team or explore our full drive range below:
