[OZAPRS] rf earth

[Damien Gardner Jnr]

On 27/04/2010, at 11:05 AM, Paul Mullins wrote:
> Connect one end of the hookup wire to your earthing system, "make  
> sure there
> is NOT MAINS VOLTAGE PRESENT" believe it or not some stobbie poles  
> are alive
> remember safety first people. I DON'T WANT TO HEAR OF PEOPLE GETTING  
> HURT, I
> mean this.

Heh, tell me about it!  When I was living at my folks place in  
Dandenong a few years back, I had hell with the RCD on the garage sub- 
board tripping every time there was a brownout, and the 2x3kva UPS's  
kicked in..  A bit of testing later, revealed the mains earth in the  
garage was *normally* sitting at ~3VAC towards active, and peaked at  
around 20VAC momentarily when the UPS's switched off battery and back  
to mains..  Not entirely sure why a floaty earth would effect the RCD  
so, but a nice 6 foot copper rod left in the bush by Actew a few years  
earlier (well actually there was a WHOLE bunch of them, along with  
some electricity poles and such.. I think they were getting ready to  
replace a power run.. but seriously, who leaves earth rods just  
sitting in the bush??) driven into the ground beside the shed, and  
attached to the earth coming the 30m up from the house solved the RCD  
problems :)

--DG


Damien Gardner Jnr
VK2TDG. Dip EE. GradIEAust
rendrag at rendrag.net -  http://www.rendrag.net/
--
We rode on the winds of the rising storm,
  We ran to the sounds of thunder.
We danced among the lightning bolts,
  and tore the world asunder

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