Lightning Protection

[genhead]

Hello all,
I have attached details of a lightning protection device that a customer has asked us to fit to some mobile equipment which has a steel mast.
The equipment is on rubber tyres and there is no grounding conductor.
1. How does it work?
2. Does it work?
Thanks

 

[waross]

The equipment is on rubber tyres and there is no grounding conductor.

From the attached information:
"Requires no additional grounding".
And tires have enough conductivity to discharge static charges.

2. Does it work?

From a statistical point of view I would be happy to offer a full money back guarantee with no further liability.
If one in 10,000 units sold is destroyed by a lightning strike, the PU cost of one refund is negligible.

 

[3DDave]

It works by attracting the cash from unsuspecting buyers in exchange for betting that anything attached to it will make it 10 years without being hit by lightning.

The roof rack on the car has been doing that for more than 10 years, and a great job of it too.

 

[LittleInch]

They seem to be called "fuzzy dissipators" and more commonly seen on boats apparently.

This claims they don't work https://www.boatus.com/expert-advic...ghtning-protection-on-recreational-watercraft

As does this https://www.cruisersforum.com/forums/f14/lightning-dissipator-any-good-99714.html scan down a few posts.

As it says there is some "science" behind it and the question is whether it does just enough that the lightening strike goes somewhere else, but on its own in the middle of no where I doubt it.

Also if you're in rubber tyred vehicle and there is lightening around, this thing may just charge up your vehicle enough to give you a nasty shock if yu exit the vehicle and earth it...

 

[EdStainless]

They are supposed to help dissipate the static charge that builds prior to a lightning strike.
If there are a lot of targets around, then it should help yours not be struck.
If your equipment is the highest thing for a mile then forgetaboutit.

 

[Compositepro]

Brushes are very effective for dissipating static charge in many applications, however, they (or the other object) must be grounded.
Sharp points on conductive objects in an electrostatic field, cause the electric field to become very concentrated at the point. This causes a corona discharge at the point where the air becomes ionized. These ions in the air move toward the opposite charge and get neutralized. But there has to be a source of electrons. The earth is considered to be an infinite source or sink of electrons. A finite object will quickly become charged as it is sourcing or sinking electrons.

Normally the brush is grounded and will dissipate charge from nearby objects without an arc discharge. This is how some static eliminators work, and some argue that is how lighting rods work. However, lighting will also just strike the nearest ground. I guess the argument can be made that a boat or other object that is charged at same polarity as the lightning will tend to repel the lighting. There are so many other factors involved with where lightning will strike that it is difficult to statisticly prove that this hypothesis actually works.

 

[waross]

And tires have enough conductivity to discharge static charges.

 

[genhead]

Thanks all for the responses.
The client has requested that we fit them so we will, but with a disclaimer that clears us of any liability for their effectiveness (or lack of).