Extra/Auxilary grounding rods..... Don't do it.

[marionw]

Lightning happens when a really huge negative charge builds up in the ground, corresponding to a positive charge overhead, and the differential becomes sufficient to jump the gap. (and, as others are pointing out repeatedly, air is an excellent insulator, so it takes a whacking huge voltage differential to make the arc.)

A lightning rod doesn't exist to provide a spot for the lightning to strike. Rather, it exists to dissipate the charge so that the strike never happens at all. This comes from early experiments with the Leyden jar; if a pointed metal rod was attached to the jar, it wouldn't charge. The electrons are able to leap off a pointed tip, and into the air, dissipating charge as fast as it accumulates. The lightning rod does the same thing, on a larger scale; it spits out electrons into the air like crazy, so that the charge won't build up sufficiently, and the lightning never hits at all.

Now, if the charge accumulates faster than the rod can dissipate it, there can still be a lightning strike, and the rod typically IS the best route to ground. But everything around the rod is going to take a hell of a jolt anyway, including, most likely, your electronics. A lightning rod getting hit means it failed to work adequately; ideally, it should never be hit at all.

Does a lightning rod prevent lightning strikes?

I was always under the impression that a Lightning rod worked to protect a building by being the tallest part of the building and having a low path of resistance to the ground, thus being a good ta...

physics.stackexchange.com

 

[robbob2112]

Lightning happens when a really huge negative charge builds up in the ground, corresponding to a positive charge overhead, and the differential becomes sufficient to jump the gap. (and, as others are pointing out repeatedly, air is an excellent insulator, so it takes a whacking huge voltage differential to make the arc.)

A lightning rod doesn't exist to provide a spot for the lightning to strike. Rather, it exists to dissipate the charge so that the strike never happens at all. This comes from early experiments with the Leyden jar; if a pointed metal rod was attached to the jar, it wouldn't charge. The electrons are able to leap off a pointed tip, and into the air, dissipating charge as fast as it accumulates. The lightning rod does the same thing, on a larger scale; it spits out electrons into the air like crazy, so that the charge won't build up sufficiently, and the lightning never hits at all.

Now, if the charge accumulates faster than the rod can dissipate it, there can still be a lightning strike, and the rod typically IS the best route to ground. But everything around the rod is going to take a hell of a jolt anyway, including, most likely, your electronics. A lightning rod getting hit means it failed to work adequately; ideally, it should never be hit at all.

Does a lightning rod prevent lightning strikes?

I was always under the impression that a Lightning rod worked to protect a building by being the tallest part of the building and having a low path of resistance to the ground, thus being a good ta...

physics.stackexchange.com

One other tidbit in this case - the lightning rod itself serves as a coronal point. The reason they come to a point it to bring the point of a strike down to a single fine point that will melt when hit. The amount of current in lightning is typically very small compared to the voltage. So by melting the coronal point you can disipate a lot (not all) energy in the strike.

 

[timselectric]

And my new build the only ground is a UFER. Let's throw that into this discussion LOL

Excellent choice.

 

[seneysolar]

SPD = Surge Protection Device
Protection from surges, not lightning.
This is what people need to understand.

Midnite seems to be advertising their SPD's for lighting protection...

Edit: To be clear i doubt it will do much for a lighting strike but its not my area of study. msybe it would help if it wasnt too close? I think this kind of advertising is what steers people down the lighting protection path.

 

[timselectric]

Midnite seems to be advertising their SPD's for lighting protection...

Edit: To be clear i doubt it will do much for a lighting strike but its not my area of study. msybe it would help if it wasnt too close? I think this kind of advertising is what steers people down the lighting protection path.

It won't protect against a direct lightning strike.
It will hopefully protect against the gradient pulse (surge) created by a nearby lightning strike.
Luckily, the odds of a direct hit are much lower than a nearby strike.

 

[42OhmsPA]

I known it has been shared on here before, for anyone that missed it this is a great video on Midnite SPDs.

 

[ricardocello]

I known it has been shared on here before, for anyone that missed it this is a great video on Midnite SPDs.

Makes me feel better about buying 6 of those things.
They aren’t cheap, but I can sleep peacefully at night when the storms come through.
And I like the Blue LEDs.

 

[42OhmsPA]

Makes me feel better about buying 6 of those things.
They aren’t cheap, but I can sleep peacefully at night when the storms come through.
And I like the Blue LEDs.

I only have 2 on the AC side, really need to get around to adding some to the DC side. Yes, the LEDs give a nice peaceful feeling knowing things are protected (hopefully).

 

[timselectric]

They definitely work, and I believe that they are worth the money.
I just wish that they had a better form factor that was easier to install in more situations. And I would rather they had a more modern look. Instead of the 1960 film robot head.

 

[42OhmsPA]

Redesign them to look like a lightning bolt through the sun and take my money if LED colors are proper for the design.

 

[ricardocello]

I only have 2 on the AC side, really need to get around to adding some to the DC side.

I’m the opposite, only one Midnite on the AC side, but I also have two other Schneider SquareD in two different panels as well.
On the DC side I have one at each ground mount array (3), and one on each PV feed into the house (2). Probably overkill.

 

[42OhmsPA]

I’m the opposite, only one Midnite on the AC side, but I also have two other Schneider SquareD in two different panels as well.
On the DC side I have one at each ground mount array (3), and one on each PV feed into the house (2). Probably overkill.

Nothing wrong with overkill... So the PV LEDs light during daylight hours and go off at dark?

 

[ricardocello]

Nothing wrong with overkill... So the PV LEDs light during daylight hours and go off at dark?

Yes, and they are visible well into twilight.
I haven’t determined what the PV voltage cutoff is for the LEDs, but it’s pretty low, probably 50v or so, maybe even less.
I use the 300V rated ones.

https://www.midnitesolar.com/productPhoto.php?product_ID=284&productCat_ID=23&sortOrder=2&act=p