Martin: Contact me directly nando37 -at- comcast -dot- net to avoid loading the group.
Number of poles define the RPM for a desired output frequency: Basic RPM = (Freq * 60 sec/minute)/ ( P/2) P= number of poles Freq= 50 Hz for you So for a P=6, the RPM = (50 *60) / (6/2) = 3000/3= 1000 RPM As a generator one needs to add the Slip value that could be from 3 to 8 % or 1030 to 1080 ( + or -). If you use a 60 HZ machine for 50 Hz generation, you will have the 230 volts without any problem, this has been done very often by many, and I mean many. The capacitance with the RPM and the motor parameters sets de frequency and the voltage with the RPM above de Slip value that is limited by the load and, in a secondary way, by the ballast load controller -- this action reflects to the Turbine that is slowed down by the load, placing the voltage and frequency at the right points. Induction Motor as a generator can have the output voltage and frequency set at different set points, keeping power and voltage within the limits of the motor capabilities and of course the power source feeding the motor. The motors in Chile are available, new and used, and as I told you, there are people there that are doing what you want do. Here in USA, depending where you are, you could find motors, cheaper than EBay, by going to the industrial metal junk yards, you may buy them by the weight cost, 3 phases and/or higher power are cheaper, though you need to know how to test what you buy. Converter/Inverter rated motors you need to analyze to make sure you do not have ELC controller problems. QUESTION: What power level are you expecting to be able to produce in your place ?. What type of ELC are you going to use ?. What type of Turbine you are going to use ?. Can you calculate and define your system buy just taking water measurements and site parameters, including the calculation of loads, motor starting definitions and solutions, problems of small power sources when multiple loads are turned ON/OFF ?. There are many more other questions in the Hydroelectric Alternative Energy BAG. The way you are writing indicates that you are not very much familiar with the motor electrical principles and that you are delving in technical areas where you may need a lot of help, I hope I am wrong. !! Microhydro energy production is easy BUT difficult if you do not have experience and technical principles in Electrical, Electronic, Mechanical, and Civil Engineering Regards Nando ----- Original Message ----- From: "chilechinadollz" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Thursday, October 20, 2005 3:10 PM Subject: [microhydro] re: induction motor as generator derated to 50Hz > Hi Nando, Wayne, Manfred and all, > > First thanks again for the help. My research to date regarding > differences between 50 Hz and 60 Hz machines, seems to indicate no > difference between the number of poles. The motor will have either > 2,4,or 6 poles and that will determine rotation speed at either of the > two frequencies. What I haven't yet determined is the effect on > voltage. I suspect that 50 Hz machines may be wound differently. If > I take a 60 Hz, 230 V motor and spin it slower to get 50 Hz, I will > probably also get a lower voltage. Not good of I want 230V, although > I've read that I may be able to up the voltage by changing the > capacitance. Will have to delve into this more. > > Of course I could just buy a 50 Hz machine in Chile, but I can find > good prices on new/surplus motors here on eBay. For example, I can > get a 25hp, 3 phase, industrial built new motor here for $100. I > don't think I could touch that motor for less than $800 new. I can > also get inverter duty motors here. I don't have the foggiest of > where to begin to find similar stuff in Chile. Of course there are > shipping costs involved, but I'm going to ship a bunch of stuff down > in a container anyway. > > Martin > > > > > > > > > > Does your company feature in the microhydro business directory at > http://microhydropower.net/directory ? If not, please register free of > charge and be exposed to the microhydro community world wide! > > NOTE: The advertisements in this email are added by Yahoogroups who > provides us with free email group services. The microhydro-group does not > endorse products or support the advertisements in any way. > > More information on micro hydropower at http://microhydropower.net > > To unsubscribe: send empty message to > [EMAIL PROTECTED] > Yahoo! Groups Links > > > > > > > ------------------------ Yahoo! Groups Sponsor --------------------~--> Get fast access to your favorite Yahoo! Groups. Make Yahoo! your home page http://us.click.yahoo.com/dpRU5A/wUILAA/yQLSAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
