Hi Guys. There are two different streams of correspondence on this topic, so I am including this in both in the hope that one or other will be picked up. Apologies if you end up with both. In summary, I have had the same problem. Using a neon screwdriver, I am detecting current in a ‘floating’ earth wire in a lighting circuit. I am off to get a decent voltmeter to check just how much voltage there is in the earth wire. I want to make sure that I have understood the advice. So here goes. I check the voltage between the neutral and the earth. If this is below (what?) 30V this is ‘normal’. I should then connect the earth wire to a good earth. The current should then run off down the earth without tripping the circuit breaker at the switchboard. Have I got this right?. Thanks. IanC.
Earth wire in three core lighting cable appears to be live
- Thread starter gacw
- Start date
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If an earth wire is not in fact earthed then it may have an induced voltage on it from nearby cables or attached equipment. This can be enough to light a neon tester but does not necessarily indicate any fault ....except having no earth! The earth cable should stay at earth potential if it is actually connected.
Of course maybe you are at higher than earth potential, so you are powering the neon to the properly earthed cable.
Of course maybe you are at higher than earth potential, so you are powering the neon to the properly earthed cable.
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