Norm of Bandersnatch wrote: > I don't know anything about a "dump" load, there was nothing in the manual > about that. The lit says there are protective devices in the generator, but > no details about how they actually function, that protect the unit in high > winds. I imagine they disconnect the load when the unit heats up. > I really doubt they simply disconnect the load! A 'dump' load is what is used to keep the batteries from being overcharged, otherwise when they are full you would need to disconnect them from the generator, therby 'unloading' it. It is a design problem with perm mag alternators such as these wind gennys use that since the magnets are always rotating when the blades are spinning, making flux lines pass through coils, there is no good way to 'shut off' such a device electrically (as with electro magnets in a car alternators field windings that can be shut down or reduced to effectively lower output current through a given load and also voltage as a function of that), because if the PM alternator is simply electrically disconnected from the load, then there is no current flow through the coil windings and the output load, and so no back EMF is produced (Electro Motive Force, the magnetic force that causes a voltage to flow in an inductor or coil when exposed to a changing magnetic field flux) in the coil windings to counter the voltage across the output, which will then rise to very great levels possibly blowing rectifier diodes and maybe even 'punching through' the coil windings.
Also, since no electrical load means no back EMF there is no counter torque. This is bad because without that to keep it from going too fast it will run away like a truck going down a mountain with no brakes. If you are not using a 'dump' load than it means you have enough batteries/load connected so that you have not needed it, otherwise you would have severely overcharged them by now. Not a problem for you, perhaps, but with my boats 330AH capacity, it would be a big problem. My Air Marine can take the batteries from 50% to fully charged in just an afternoons worth of summer thundersqualls in a good location. After that, if it was not regulated, the bank would be in trouble. I don't use more than 15 AH most days, and I can get that in 1/2 hour with my wind genny! BTW, there is another type of solar panel regulator just in the market now, it doesn't just regulate or limit max power to the batteries from solar panels, it also boosts the solar panels voltage when needed via a switch mode controller and keeps the voltage high enough to keep charging in low angle sun, when the output of the panels by itself would not be high enough to charge effectively. It can add as much as 20% in total AH per day, but it is not yet cost effective for most applications as it is still cheaper to just add 20% more solar panels. In any case, the KISS may now have an internal 'dump' load similar to the way a motorcycle PM alt. regulator works by shorting out the load to ground through the regulator casing when the battery is fully charged. This would of course also act to limit blade speed. But since this type of design makes the genny run as hard as it can when wind speed is above a certain level, the output either all going to power in the house bank or some in another load, it can make the magnets overheat. When that happens all control is lost and unless it is 'furled' it may run-away. However it would take more than a short lived event for that to happen.-Ken > _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
