wind turbine need a fuse?

[Sailingsaves]

Summary first: If a fuse is used when installing a wind turbine and the fuse blows, the turbine will be damaged (possibly beyond repair) would it not?

Discussion:
If a wind turbine is connected to a controller that allows dumping etc, would a fuse from the turbine before the regulator (or even after) be a BAD idea (If the wires are thick enough and protected from ever shorting) .

Because if the fuse blew, the turbine would continue to turn and the current has nowhere to go and hence the stator will be damaged?

But many manuals state a fuse should be used.

If the wires are thick enough and protected from ever shorting, can a fuse be omitted for the sake of not killing a turbine?

 

[Rum Run]

Given the paltry output of most small wind turbines, unless the cable is very thin I'd assume no fuse required.

 

[VicS]

There should be a fuse in the connection to the battery, as close a practicable to the battery. Its purpose is to protect the wiring from the very high current wch the battery could deliver in the event of a fault

The fuse rating should be less than the safe working current of the wiring, but more than the max expected output from the charger. The wiring should be not only able to safely carry the max generator output but be sufficiently over sized to keep voltage drop within acceptable limits

 

[William_H]

Summary first: If a fuse is used when installing a wind turbine and the fuse blows, the turbine will be damaged (possibly beyond repair) would it not?

Discussion:
If a wind turbine is connected to a controller that allows dumping etc, would a fuse from the turbine before the regulator (or even after) be a BAD idea (If the wires are thick enough and protected from ever shorting) .

Because if the fuse blew, the turbine would continue to turn and the current has nowhere to go and hence the stator will be damaged?

Please excuse my ignorance but why are you so certain the turbine stator would be damaged? Yes I can imagine ina very high wind the turbine speed may be very high with no load. The possibility then that the rotor may disintegrate then possibly damaging the stator. However one of the advantages of alternator is that the rotor is the field coil and can be wound in the same plane as the axle hence very resistant to centrifugal forces. Or they might use a permanent magnet as a rotor for field magnetism. Also robust and resistant to centrifugal forces. I would think the load dumping is just to control the speed of the turbine to reduce noise and vibration.
Regarding the fuse as Vic said it is current from the battery on any connecting wire that can exceed the wire rating and cause a fi8re in a short. So I would fit a fuse near the battery pos. In this position load dumping should still work. olewill

 

[Sailingsaves]

Thanks chaps,

Can understand fuse from battery to devices needing power, it is the fuse just after the turbine and before battery I am questioning.

From what I have read, if a turbine spins (even at moderate rpm) but has no load, damage can be done.

I don't know what damage they mean, but I don't think they are talking about the magnets flying apart type damage. That is why the dump load is there (or the primary load).
As long as the electricity generated is supplied to a load, the turbine is 'happy'.

If one took the load away (open circuit), it can 'break' (a bit like a car alternator suddenly being disconnected?)

I thought if a fuse was used, and it blew (which it shouldn't if wiring is calculated correctly - unless there is a fault with the fuse) then suddenly the load is removed (open circuit) and turbine can 'break' in manner that the manuals haven't really explained but I am guessing in same manner as car alternator 'break down' ?

see section 6 of this:
http://www.marlec.co.uk/wp-content/uploads/2008/10/910-Owners-Manual.pdf

and here: http://www.marlec.co.uk/wp-content/uploads/2008/10/910-Fault-Finding-Manual.pdf

PAGE 4 of this just looks plain wrong:
http://www.shop.solar-wind.co.uk/acatalog/Wind_turbine_LVM_AERO2GEN_Marine_Manual.pdf

and even page page 14 with a voltage regulator and dump resistor. What if the fuse from the positive of turbine to battery blows and one obtains open circuit whilst wind is blowing at 20mph? No electricity will reach the voltage reg or dump resistor in that diagram. What would happen to the turbine at open circuit? What can break?

Just found this for the aero2gen turbine:
"In open circuit the suppression capacitor maximum voltage may be exceeded and destroyed." if in open circuit. They too advice a 5A fuse. The 5A fuse seems to be a weak link that could destroy the capacitor (as long as one uses 10A cable and calculates for voltage drops over long runs ?)

But that's not too bad, better than stator being cooked (assuming I could source a replacement capacitor)

But does that apply to the rutland 910? I can't see a suppression capacitor in that one, So what would break on this turbine in open circuit?

 

[KellysEye]

>Because if the fuse blew, the turbine would continue to turn and the current has nowhere to go and hence the stator will be damaged?

We had an Ampair wind generator and an on/off switch when the batteries were fully charged we switched it off it didn't damage it.