What is the purpose of Noise Reduction [nrd] in an ATV61 or ATV71 Drive?

When enabled, the drive uses random frequency modulation, which helps prevent resonance in the motor or connected mechanical system. This can significantly reduce humming or tonal noise during operation.

How the Noise Reduction Parameter Works

• [No] – Fixed Frequency
  The drive operates at a fixed switching frequency.
  This is the factory default on larger drives, including:

  • ATV71HD55M3X and higher
  • ATV71HD90N4 and higher
  • ATV71HC11Y

• [Yes] – Random Modulation
  The drive varies the switching frequency randomly to avoid resonance.
  This is the factory default on smaller drives, up to:

  • ATV71HD45M3X
  • ATV71HD75N4
  • ATV71HD90Y

Drive Size Limitations

The Noise Reduction function is not available on:

• 75 HP and larger drives at 230 VAC (D55M3 and above)
• 125 HP and larger drives at 460 VAC (D90N4 and above)

These limitations  are documented in the ATV61/ATV71 programming manual.

If this article does not answer your question, check out our FAQ database that has answers to more commonly asked questions:

Frequently Asked Questions - Schneider Electric (se.com)

If this FAQ did not solve your issue, you can call us at 1-888-778-2733 Option 2 and then 4 or e-mail us atdrive.products.support@se.comto create a case with our Technical Support Team.

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