What voltage does the Windtura 750 produce?

Well I am going to try and use the voltage switch for it later as I have NO wind so far this summer. I will be using the switch hooked to the HD relay to run the low voltage one and when it gets up to like 18 volts it will disconnect the 10.8 -30 volt one. I tried it before with just the voltage switch and the relay fried. I found a replacement online and now have it hooked to the HD relay for a dump load right now. Will post more when things change. As in wind.