Quote Originally Posted by Shadyshaun View Post
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If you have been in the electrical industry for a while, you would have noticed wires which are no longer "shiny bright copper" , they are not as flexible and turn a blue/black colour, they should be replaced.
Where the wires are Blue/Black in color it would mean that excessive current has been drawn through the copper and you would need to see why before just replacing.

It is one of the reasons that running an earth wire all the way down to a Borehole pump is no longer needed as the earth to the pump ended up being the best earth around and taking excess current down to the "earth Rod hanging in water 100m down" - You would always find a borehole earth wire went blue/black in color