Wall Lights Earth


Postby ukwolfe » Mon Jul 27, 2009 6:41 pm

I am replacing a couple of wall lights. With the mains power off, I get no resistance between the bear earth wire and the neutral wire at the wall; they seem to form a circuit. This strikes me as strange but the old lights worked well and had an earthing point. There is no resistance between the switch earth and the wall earth, as I would expect. With the switch on there is a high but measureable resistance between the earth and the live at the wall.

Is this normal. Any help appreciated.
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Postby kbrownie » Tue Jul 28, 2009 9:01 am

What procedures are making when testing explain the method you are using and what you are doing to form continuity. What do you call a high reading?
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Postby sparx » Tue Jul 28, 2009 1:14 pm

Hi, sounds perfectly normal to me IF,
your main switch is on but circuit live isolated by fuse/mcb . Your low resistance circuit from neutral to earth will be because they are linked together at supply.
since switch and light earths are connected together you should indeed see a low resistance, similar to if you touch your meter probes together.
with switch 'on' the path from line to earth will be via lamps in circuit to Neutral and back to earth at supply, thus high but readable resistance,
regards SPARX
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Postby ukwolfe » Tue Jul 28, 2009 10:29 pm

Thanks for that - I was putting a meter (resistance) across the bare end of neutral and bare end of earth at the wall to get no (litttle) resistance - couple of ohms when I turned the scale to x1.

Many thanks for your time.
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