Live or neutral?

Jan 18, 2008 25 Replies

How did you do this with a multi-meter?

I followed the advice received from another well known forum :-

"Not much can be done without a meter. For a simple voltage test lik this, one of the 10 quid argos digital multimeters would b sufficient.

You could also use a test lamp, but this would not give an accurat result of whether or not the steel conduit was properly earthed

-- Unclebill

Which forum would that be?

This isn't a voltage test, it's a resistance test. And you are measuring very low resistances - which a multimeter like that won't do.

Then it's poor advice for checking an earth. Digital multimeters draw very little current and a poor earth with a high resistance - and this is exactly what can happen with conduit - will show up as 'normal' with one.

In actual fact the reverse. A test lamp will draw some current and is better than a simple volt meter. But the correct tester will draw a very high current for an instant thus checking the earth is doing its job correctly - ie capable of drawing enough current in event of a fault to trip the circuit protector within the design time.

Which raises an interesting point; many modern loop testers have a "no trip" test facility that enables measurements to be made without tripping any RCD on the circuit. With the increasing use of RCDs this will become the typical way a test like this is done.

How many of them I wonder are still able to do a high current test without tripping the RCD?

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