On Mon, Jan 21, 2013 at 6:56 AM, Mike Cinquino <[email protected]> wrote:
> > Are VFD's less noisy if they are fed 3 phase? I would think they might be > because of the switching needed to generate the 3rd phase if only fed > single phase? > VFDs work by rectifying the input voltage onto a DC bus (sometimes even the DC bus is brought out on the connectors available to the end user, presumably because there may be HV DC available already). Then, the DC is chopped/switched to generate three output phases---therefore the switching noise is always there. When you feed the unit with only one phase the DC bus filtering capacitors have to work harder providing the power when the single phase is not at its peaks. The bottom line is that it's conceivable that there's more noise in this case, but not quite for the reason you stated. You should be able to check whether this is an issue in your case---just run it at low load, and if the noise persists, it can't be caused by the single phase input. Unfortunately you can't conclude the opposite if the interference disappears at the low load---it could be the loading effects, or just the fact that higher output currents couple strongly to your Arduino. ------------------------------------------------------------------------------ Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. SALE $99.99 this month only -- learn more at: http://p.sf.net/sfu/learnmore_122412 _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
