[SOLVED] SINAMICS inverter, how to suppress distortion

[aagaag]

I have a Siemens SINAMICS V20 0,12 KW 240V inverter, which I use to drive a 2-wire fan at 17 Hz.

This arrangement works, but it results in significant emission of audible distortion at ca. 8 kHz (and higher). I would be grateful for any advice on how to suppress the distortion. I imagine that some kind of low-pass filter would be necessary, but I do not know what to buy or how to construct such.

I should also say that I am not all too happy with the Sinamics inverter. If you listen to it carefully, it emits high-frequency noise even in the absence of any load!

 

[FvM]

Pulse frequency can be configured up to 16 kHz with P1800, 8 kHz is default for single phase inverters. Check what's feasible with your load.

 

[aagaag]

Dear FvM, thanks but I do not understand. My goal is to run the ventilator very slow, at 17 Hz (not kHz). That works well, but the inverter makes a high-pitched noise, which is annoying in my setting. The load is 110 W.

 

[FvM]

Please read the inverter manual, specifically about parameter P1800. Pulse frequency is the inverter pwm frequency, it has nothing to do with output frequency.

 

[aagaag]

Dear FvM, you da man, vielen Dank! I set the P1800 parameter to 14 kHz, and the noise disappeared completely!!!

 

[aagaag]

I have one additional question related to the function of the Sinamics. I wish to start the inverter by digital input rather than manually. I have set parameters P0700 to 2 and P0701 to 1 (rather than using a connection macro).

However, shorting digital input DI1 to either the 0V or the 24V terminal does not start the inverter. The frequency of the inverter was set manually to 17 Hz. What am I doing that is wrong? here is a diagram which I have used as a guide - to no avail though.