Instructional videos with safety bits missing.

[ericmark]

There are many videos on the internet which are really bad but I am not looking at them what I looked at was a reasonable good video showing how to change a class II light fitting with ceiling rose to a class I fitting with GU10 lamps. On watching I noted:-
1) Using MCB to isolate without checking earth system in use.
2) No lock on MCB or even tape over it or notice hung on it.
3) Use of contact less tester to prove dead although he did go to lengths to test the contact less tester was working.
4) No test to see if there was a working earth connected to lamp.
Don't get me wrong here it was a reasonable video and I am sure many DIY people will benefit from watching it but I was in particular no happy with no earth test.

I started to think and realised years ago my Martindale tester had a bulb in it and so simply testing between line and earth may not be the correct method but did give some assurance the earth existed. However with my new Neon Martindale tester likely neons would light even if the earth was disconnected as they draw so little current. OK I use a earth loop impedance tester but DIY guys will not have one of these. Not happy showing how to build a bulb tester so what method can be used by DIY guy to test earth?

As to proving dead well switch on lamp switch off isolator check lamp goes off then switch on again see lamp lights so proving bulb not blown and then off again with isolator with lock, tie wrap, tape, notice or something to show it has been switched off likely better than all his contact less testers and with isolator does not really matter is TN or TT still safe.

But still can't think of a safe way to tell a DIY guy how to test if the earth is good before swapping class II to class I so how would you without low ohm meter, or earth loop impedance tester check for a good earth.

 

[Risteard]

I started to think and realised years ago my Martindale tester had a bulb in it and so simply testing between line and earth may not be the correct method but did give some assurance the earth existed.

Presumably you are referring to (John) Drummond Test Lamps, which are still available from Martindale. They use a 15W pygmy lamp. I have one as well as a Martindale with the neons.

 

[ericmark]

Never looked at any other name but yes 15W pygmy lamp. Didn't realise you could still get them. Looked like this

I googled after your post at that price not a DIY item. So question remains how for a reasonable price can a DIY guy test he has a real earth in his lights before swapping class II for class I.

If I did not have test equipment one of these

and one of these

could be made into a reasonable tester however not sure about suggesting that to a DIY guy. Could just use a standard lamp but again is that safe for DIY guy. I have an old BA22d plug with wandering earth lead and croc clip in my test bag wired to a in-line socket to make testing easy. But can't buy those plugs now mine was on my grans smoothing iron. So ideas how can a DIY'er test the earth?

 

[EFLImpudence]

Just need a multimeter and a long wire.

 

[Risteard]

I thought the pygmy lamp suggestion wasn't a bad one, and John Drummond Test Lamps are very well constructed. Could also be used as a basic RCD tester!

Seem to be just over £60 (inc. VAT).

 

[ericmark]

I thought the pygmy lamp suggestion wasn't a bad one, and John Drummond Test Lamps are very well constructed. Could also be used as a basic RCD tester!

Seem to be just over £60 (inc. VAT).

I would agree except for price, but may be I have got that wrong. What we need is a DIY guy to say what he would pay for test gear.

 

[ericmark]

Video here http://www.ultimatehandyman.co.uk/video/how-to-wire-a-ceiling-light-video_76ec58b64.html he says

The instructions were quite clear-

Isolate the electricity

Ensure the fitting is earthed

And continues to say

You say that swapping from a class II to a class I is not allowable without testing (despite hundreds of people doing this every day), you need to take this up with the manufacturers of the switch as they forgot to include this information on the instructions!

When I criticised the video saying the earth was not tested. I would have thought "Ensure the fitting is earthed" does tell one it needs testing.

However I freely admit in the main not a bad video and having considered it I fail to see an easy method to demonstrate the earth is connected.

Either you need some continuity tester or you need to power up while the fitting is hanging off the wires. Multimeter and long wire to socket, radiator etc would likely prove earth. Since the second tester used costs over a £100 I suppose a multi-meter would not stretch the pocket!

Yes I have one of these

in my tool box and I have used it to test for power although bought to test magnetic pulse which are cheaper but the old reed switch tester is really just not good enough even a small tap can mess them up.