What generator do I need for a 3 HP air compressor?
Do you have a powerful air compressor but don't know which generator you need to make it work without problems? Here we give you the clear and direct answer, without unnecessary technical detours.

🔍 How much power does a 3 HP compressor consume?

A 3 HP (horsepower) motor is equivalent to about 2.2 kW of mechanical power. But that's not all:

  • Estimated electrical consumption: between 2.5 y 2.8 kW, considering engine efficiency.

  • Starting peak: can be between 2 and 3 times more than the rated power, i.e. up to 7.5 kW for a few seconds.

⚡ Recommended Generator 

CharacteristicRecommendation
Minimum Power5 kVA
Ideal Power6–7 kVA (for safety margin)
Type of GeneratorSingle Phase (if the compressor is 230V) or 3-phase (if it's 400V)
Recommended ExtrasAVR regulator, electric start, thermal protection


💡 Tip: If your compressor has direct start, the peak consumption will be higher. If you have a star-delta starter or variable frequency drive, the generator may be smaller.

🧠 What if the generator is too small?

  • The compressor will not start or it will start with difficulties.

  • You can damage the motor of the generator or the compressor.

  • The generator works under strain, with the risk of overheating.

🛠️ What if the generator is bigger than necessary?

  • You will have more safety margin for other tools.

  • More stability and life span.

  • But you will also have more weight, conmsumption and costs.

📌 Practical Conclusion

For a 3 HP compressor, don't risk it: choose a generator of at least 5 kVA, and if you can, go up to 6 or 7 kVA to work with peace of mind. Make sure it has AVR and good ventilation if you are going to use it for hours.

📥 Download Quick Guide

Do you want a table with recommended tools and generators?

👉 Download PDF Guide here

📣 Do you have questions about your tool?

Write to us or leave us a comment. We help you choose the perfect generator for your job.

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