[geeks] Whee! Lightning strikes, AGAIN!

[Shannon Hendrix]

On Jul 29, 2009, at 10:16 , Lionel Peterson wrote:


>> Find out what the lightning is attracted to and maybe eliminate it,  
>> move it,
>> or alter it.
>>
>> If you can't do that, and maybe even if you can, you need to ground  
>> the
>> strikes to prevent them from entering structure and wiring.
>
> I'd like to erect a tower in my yard, but I'm honestly afraid of what
> it would do, lightning-wise... I agree there is something about my
> location that makes it the best conductor around, but while a tower
> would change the dynamics, I'm not sure if it will dissipate or
> attract future lightning strikes.

A tower might attract strikes, yes.

But a properly done protection system won't: it will intercept and  
ground them.  In other words, it doesn't go out and get them, it  
intercepts what are already local strikes and brings them to ground.   
The idea is that you were going to get a close hit anyway, so bring it  
to a controlled ground.

Obviously you want that done by someone who knows what they are doing.

> I think my hardware was killed by an EMP, because the computers work
> fine, except the NICs - every NIC (save one, so far) that had a wire

Just a nit from the acronym police:

EMP is an acronym that refers to nuclear induced, complex multi- 
pulses, and what lightning does is nothing like that.  It is even an  
IEC standard.

EMP has three parts, called E1 through E3.

E1 is the result of a gamma radiation burst, that tosses electrons  
downward at >90% light speed.  This is what destroys electronics and  
communications during an EMP, because it is too fast for normal surge  
suppression equipment to stop.

E2 is a less powerful and fast pulse and is the one most similar to  
lightning induced electromagnetic pulses, or induced current charges.   
This one can be stopped by high quality surge suppression.

E3 is the last and longest pulse, lasting many seconds to several  
minutes, and primarily affects long power lines and transformers.

So lightning generates lowercase "simple electromagnetic pulse", not  
EMP.

> The dead switches, router, and cable modem all power on, but have dead
> NIC ports, again, discounting the idea a power surge came in the power
> line in my mind.

Yeah, that's an induced current from the strike, mostly likely.

I'd be curious how much those suppressors Geoff pointed out cost.

In the end, that's what all this is: a cost/benefit analysis.


-- 
"Where some they sell their dreams for small desires."