Hello Radu: First thing, when you provide a link, please do not enclose it in parentheses ( ). It makes the link inoperable for those people who have browsers that handle the links.
Secondly, I think we need to back this conversation up and start at what should have been the beginning. You cannot really discuss a mini hydro installation intelligently, unless you give some idea of the loads that the system is expected to carry, hopefully the timing of those loads, and other details of how the system is operate. This is particularly important for a system that is off grid or "stand alone". Your system may require 24vdc or 48vdc to satisfy the other design parameters of the system, which would render the discussion of auto parts moot. Automotive parts, particularly those off of small to mid-size cars such as the Camry, are designed for intermittent operation (Say 4 hours a day, on average). As such they are generally bad choices for a reliable mini-hydro system. However, if your definition of a mini hydro system is a few batteries, say 100-200 amp hours a day (1,200- 2,400 watt hours to provide a few lights or run a small refrigerator in an off grid situation), you may be happy with a stock alternator. If you are buying them cheap enough (say $10 each) you can simply change them out and throw them away 4-5 times a year, your generation costs you about $40-50 a year. A better system would be built with an alternator designed for diesel service, especially off of a large truck, construction equipment or farm equipment. These would have a higher design standard for operation, say 10-12 hours a day. The odds are that they will last longer than the passenger car parts, and you can often get heavy duty or extended service life replacement parts. Some of these (at least in the US) are 24vdc systems, which have many advantages, particularly for larger systems and battery banks. If you are working on a bigger budget and the facilities are available, you can have alternators rewound like Doug did, and have basically a custom designed product. Doug also made an extremely important comment about better cooling. Car alternators sit right behind the fan and are exposed to a breeze that is generated by either the car movement or the fan. Although this is a "warm" breeze, there is a lot of air movement, and the alternator sees it as "cooling" air. The alternator has it's own miniature fan right behind the pulley. In warmer climates and a stationary mounting, this small fan is inadequate for running the alternator near its' max loading for a given rpm, for hours on end. This results in overheating. It will lead to premature failure of the windings as compared to an identical alternator being run at a reduced load, or one with better cooling provided. I happen to know that Ron is located in Bolivia, so I did not mention the potential overheating problem to him, and forgot to mention it to Manfred. In my judgment, it is a non-issue for Ron, due to the relatively low ambient air temperatures in his location. Not knowing the typical temperature of the area where you would intend to locate the system is one of those small details that is important to know. While I might tell him to go ahead and use a car alternator, my advice to you might be "Don't do it without auxiliary cooling". This would be another parasite load, which would further reduce the overall efficiency of your system. This illustrates one of the dangers of reading advice about one particular system or circumstances, and assuming that it applies to your situation. Personally, I would look for a generator or an industrial motor designed for continuous service, and start with that. These can often be picked up in the US for scrap prices. Some of these are still in serviceable condition and would just need the windings dried out before putting them in service. Others can be rewound/rebuilt fairly inexpensively. They will provide far more reliable service in the long run. Although the Balmar heavy duty alternator is brushless and it would be a better choice than the Camry alternator, Ron is not going to find one of those in a junk yard in Bolivia. I would also want to ask Balmar for their expected bearing life, before purchasing one. In their regulator manual, they say to check the bearing of the 90 series alternators for excessive noise (that means wearing out) at 1,000-2000 hours. In continuous operation, that is 42-84 days. If the mini-hydro system operator is a good mechanic/electrician, brush or bearing replacement is not a tremendous burden assuming the spare parts (or replacement alternator) areon hand. Some people will accept this as routine maintenance. In other cases, lack of tools, local expertise, and difficulty of obtaining replacement parts/expense of those parts, will make this an unbearable burden and you will end up with a system that out of service more than it is operational. The regulator manual that you referenced is for a marine or boat application. Although it would be a better choice than the stock Camry regulator, it is still made for a certain range of battery bank size. The other thing they did not tell you, is that it is really intended to provide surplus electrical power to the house batteries while the main engine is running. They do not promise to fully charge your battery bank. A big boat with large battery banks normally has an aux generator/battery charger. When the house bank is drawn down, you fire up the 5kw aux. generator to fully recharge the batteries in much less time than the engine alternator(s) will take. The regulation of that power is in the onboard charger. I can also tell you that the M in marine, doesn't really mean marine, it means MONEY. I did not see the price on that regulator, but I would wager that it is over half of the cost of the Xantrax C-40 unit, if not just as expensive. The C-40 costs about $150 in the US. It will handle larger battery banks and will work better with whatever inverter you might be using. To sum all of this up, my general advice would be DO NOT use automotive parts for a reliable, low maintenance, efficient system. The stock, unmodified car parts, although they may have an attractive initial purchase price, often will have a greater life time cost (life of the whole system, not of the component), than the proper equipment will. Get something that is designed for power generation/continuous service. If you feel your circumstances mandate the use of auto parts, then describe those circumstances and the system you want to build and we can try to help you with it. Oso --- In [email protected], "Radu Babau" <[EMAIL PROTECTED]> wrote: > > Hello Oso, > > > Acc. to the www.balmar.net, seems that they have produce heavy duty > alternator - 98 series (http://www.balmar.net/Page13- 98seriesalts.html) > which is brushless type. No brushes to wear is something, but it needs > external max charge voltage regulator. Acc. to the regulator manual > (http://www.balmar.net/PDF/ars-brs.pdf), page 8, when the voltage is bellow > the 14 Vdc (adjustable), the regulator keeps a constant current output > (adjustable acc. to the battery charging capabilities). When the voltage > reaches 14Vdc, it switches to contant voltage mode (voltage regulated mode). > > Maybe this is good news. The bad news may come with the price offer. > > About how voltage regulator works, acc. to things listed on > www.prestolite.com, these have to insure propper variable excitation for the > alternator, in order for the output voltage to be kept stable, no matter the > shaft speed or battery status > (http://www.prestolite.com/literature/tech/alts/TSB- 1022_Wiring_Diagrams_4800AA_Series.pdf). > Of course, you cannot get more amps than the alternator provides at that > speed. Acc. to what I understand from these manuals, this behaviour is > apparently good for generating purposes. > > Using external rectifier diodes is a good choice. Perhaps brushless is also > a good next step. > > However, I have not worked with my hands on any of these units. > > > BR, > > Radu > ------------------------ 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/
