SPD Question

[Alanbrad]

its really a healthy discussion. thanks for the tips, it is useful for me.

[grizzley]

Hi Peter K,
I suppose you have your tower build by now - how is it working out?  We have a 60 foot wind turbine tower 300 feet away from the house.  When we did maintenence on the turbine we saw it had gotten struck multiple times by lighting in the past year.  The tower is grounded well and we only have a SPD 300 on the incoming wires of turbine controller at the house.  The system at the house is fine. 

Does anyone have an idea how one can tell if the SPD got hit.  I am curious to learn if the grounding worked well enough not to bring any charges to the house or if the SPD saved us form any damage?

[boB]

Hi Peter K,
I suppose you have your tower build by now - how is it working out?  We have a 60 foot wind turbine tower 300 feet away from the house.  When we did maintenence on the turbine we saw it had gotten struck multiple times by lighting in the past year.  The tower is grounded well and we only have a SPD 300 on the incoming wires of turbine controller at the house.  The system at the house is fine. 

Does anyone have an idea how one can tell if the SPD got hit.  I am curious to learn if the grounding worked well enough not to bring any charges to the house or if the SPD saved us form any damage?

Do the LEDs on the SPD still light up when there is voltage on the lines ?   At least the positive LED ?

If so, that means that the fuse inside the MOV did not blow and it may still be OK.

The negative line may not normally light up though because it is usually grounded.
boB

[grizzley]

Hi Bob,  thank you.  The LED's  are still lighting up when the turbine runs.  The exterior of the Generator core shows four burn marks form lightning strikes.  It sounds like from what you are saying that if the LED's are lit the SPD is working but there is no other way of telling if it has "difused" a strike or other event.  Is that correct? 

[boB]

Hi Bob,  thank you.  The LED's  are still lighting up when the turbine runs.  The exterior of the Generator core shows four burn marks form lightning strikes.  It sounds like from what you are saying that if the LED's are lit the SPD is working but there is no other way of telling if it has "difused" a strike or other event.  Is that correct?

Right.  At least, the MOVs are in tact.  They may have reduced effectivity but are still MOV's.

The SPD is pretty tough.  It may be that the SPD is still fine ?

Did anything break as far as you can tell ?  That's a pretty darn good test !

boB

[Halfcrazy]

If it where me and there was evidence of 4 separate direct strikes I would mark that SPD Used somehow and add a new SPD in parallel with it to be safe. See the way a MOV works is it wears down like break pads when it is used. So the magic question is do you have enough MOV to stop the next hit?

[grizzley]

If it where me and there was evidence of 4 separate direct strikes I would mark that SPD Used somehow and add a new SPD in parallel with it to be safe. See the way a MOV works is it wears down like break pads when it is used. So the magic question is do you have enough MOV to stop the next hit?

Thank you both.  I still have a new one sitting around unused so I will put that in, just to make sure.  We are off-grid so safety of the system is key otherwise we may have nothing.