Lightning electrodes

Historically there was a reluctance to fit lightning conductors to Churches, on the grounds that the lightning was sent by God, for His reasons, and we mere mortals should not attempt to defy the will of God.

A proponent of the then new lightning conductors stated that cold winter weather was also sent by God, but that the Church accepted the use of overcoats in winter !

ISTR reading of a huge disaster in Italy. A vast store of gunpowder was being kept ready for a war, and was stored in the church, this being considered a suitable place to store explosives.

During a thunderstorm the local populace sheltered in the church, ringing the bells to ward of the lightning. The church was struck by lightning, the gunpowder exploded, and most of those sheltering therein killed.

I read somewhere that Benjamin Franklin ,who studied lightning, had opposition to fitting lightning conductors to churches for this very reason.

Thanks Mike. Yes it is a complex subject. I rather think that is the attraction for me but unfortunately reports, plans, invoices, quotations and general day to day business prevent me from any deeper diving. I am glad that this forum has people like you who are infinitely more clued-in than me!

I have test instruments that allow the FOP and stakeless methods, as well, of course, as the standard earth loop. Just out of interest, we used all three with results being fairly similar. Comparing the FOP result with the loop results we figured that the DNO connection to earth was around two ohms or below. 
So our results show an electrode well outside acceptable as far as code recommendations are concerned but the overall resistance below that required 10 ohm value. As David Z indicated, the resistance may only be a lesser component in what is a non-linear arrangement. 
With the greatest respect to the LPS contractors, I doubt whether they could offer an answer as to the seriousness of the situation other than to say it’s outside code and here’s a quote for fixing it. 
 

I should also say that Alasdair‘s advice is likely what will be followed. I was just interested in the actual physical risk rather than codes and insurance requirements. 

lyledunn: 
 

 I suspect that previous tests were done without removing the test link at each down conductor! 

The test link would not be removed if the 2-clamp (or double-clamp) method is used? But I agree it's far from good practice not to inspect the connection of the tape to the electrode.

gkenyon: 
 

lyledunn: 
 

 I suspect that previous tests were done without removing the test link at each down conductor! 

The test link would not be removed if the 2-clamp (or double-clamp) method is used? But I agree it's far from good practice not to inspect the connection of the tape to the electrode.

The clamp method will still indicate a bad electrode. Our measurements varied significantly at each electrode whereas the previous results indicated around 4ohms at each point. 

By the way, no main bond to LPS and no SPD. Just more issues to explain the consequences of!

lyledunn: 
 

By the way, no main bond to LPS and no SPD. Just more issues to explain the consequences of!

But small churches do not have much valuable delicate electronic stuff that may be damaged by a strike do they? Perhaps a heating programmer and a small audio amplifier. Appliances can just be unplugged after use to protect them.

Z.

Here is a link to the disaster in Italy, death toll was reportedly in the thousands.

https://en.wikipedia.org/wiki/Brescia_explosion

lyledunn: 
 

gkenyon: 
 

The test link would not be removed if the 2-clamp (or double-clamp) method is used? But I agree it's far from good practice not to inspect the connection of the tape to the electrode.

The clamp method will still indicate a bad electrode. Our measurements varied significantly at each electrode whereas the previous results indicated around 4ohms at each point. 

Agreed, when I've been involved with this kind of situation on periodic infrastructure inspections, degradation of each electrode is monitored, and, when it exceeds the limits of the standard, further investigation or, more frequently, replacement or repair of the electrodes exceeding the limits of the standard is  recommended (and usually carried out).