voltage sensitive relay

[halfcrazy]

I am looking for a relay or such that basically gives me a N/O state until a set vdc is hit preferably adjustable but in the neighbor hood of 135vdc. I want to build a device that will short my turbine if the voltage gets to high or has some one already devised said device? It has to act instantly

[joestue]

is it really a good idea to short it? relay contacts can bounce.. and that will fry them.
far easier just to hook a voltage divider up to a comparator and use that to feed some igbts/fets with dump loads.
if you think the dump load is going to fail, just build a second one.

[ghurd]

http://www.briery.com/wind_turbine/build_log8.html

G-

[jarrod9155]

omron makes theses relays 60 to 600 volts sensing and run of 110 ac .