Variable Speed Drives And Stray Voltages In Dairy Farm
Posted 06 January 2008 - 03:44 AM
There is a lot of fog and theories about Variable speed drives creating stray voltages and causing problems to cows in dairy farms.
I know cows are sensitive to stray voltage, but do VSd's cause such voltages ?.
What are the methods to avoid/measure these voltages?
Any thoughts/ideas are appreciated.
Posted 06 January 2008 - 07:59 AM
This a definite fact and the problem can be minimized by the correct installation of the correct VFD.
The VFD generates a high voltage high frequency carrier on its output terminals. This is connected to the motor and the high frequency currents can leak in all directions.
There are a number of steps that can be taken to minimize the problem, but the first is to ensure that you start with a good drive that is easily able to comply with the European EMC requirements. Some of the cheaper VFDs just can not be quietened down sufficiently.
I have a page on installing VFDs in irrigation installations for minimum EMC and these steps are exactly the same in cowshed applications. see http://www.lmphotoni.../vsd/vsd_05.htm
If you have any further questions, ask them here.
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Posted 06 January 2008 - 10:04 AM
I tried to post a question there but it directed me here.
Just one thing more...What is the best way to measure stray voltage at say a Stanchion..?
Found this link very informative also..
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