EMI in Variable Frequency Drive (VFD) (Electrical Noise)

Thread Starter


Joined Jul 6, 2022
Hi all,

I have designed a wiring harness for measuring signals such as motor speeds, 4-20 mA sensors, and other analog signals.

I see a lot of interference in my measurements, mainly coming from the VFD that we use to drive our shafts. As soon as the VFD is on, I see these pulses which get worst when I apply a gain on the signals. The pulses are like 1 second apart, and I am sampling at 1000 Hz.

Please not that the power supplied to the VFD runs of a different power source (main grid) and the instrumentation for measurements runs of my 12V and 24V batteries.

I am using Labview and the USB 6002 DAQ device.

Can some explain to how I can reduce the interference levels? I have trying to wrap my cables with aluminum foil tape.