Safe Isolation

[Pete999]

Just like to get your vies/opinions on modern day voltage testers.

https://www.google.co.uk/search?q=s...t=firefox-b&gfe_rd=cr&ei=WmyLV7yIJsSFaNL0tKAH

The likes of those shown in the link, I was brought up with the John Drumond type, where to be able to prove safe isolation had been achieved you needed a proving unit.

Personally I have never used anything but my old trust JD set up, I was chatting to a newly qualified Electrician, and the question of safe isolation came up, he proudly produced is Stienel tester and when I asked him what sort of proving unit he had, all I got was a blank stare, he said his tester doesn't need to be proved using a proving unit, it is self proving and proceeded to show me.

Now comes the question, and to be honest I'm not sure of the answer, in my opinion and I could be wrong, all the internal test prove is that the electronic circuitry is working OK. Would love to hear some of your thoughts. Should they be tested with the use of a proving unit, as I said I have always used a JD indicator so I have no experience of the Stienel type.

 

[snowhead]

I wouldn't rely on any self testing item.

It's either proving unit or known supply, before and after.
Using a Batteryless tester.

 

[7029 dave]

I still got my JD and proving unit, but we use an approved voltage tester these days, the one I have in my kit is the megger dcm340, which is a good meter. Never used any type of self testing item, don't think I would like to either.

 

[ruston]

I have an old Stienel, nothing fancy . 25 years old and still going strong.
I tend to agree with the sceptical brigade and stick to proving on a known source.

 

[edexlab]

Yes all its doing is checking the internal circuits and less
I've had a steinel 1146 since I started and a few people have looked at them and wrongly assumed that they can self prove.....
I just asked them how they thought it could produce 400 AC/DC from two 1.5v DC batteries!
Nobody's answered yet!

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[HandySparks]

...I just asked them how they thought it could produce 400 AC/DC from two 1.5v DC batteries!
Nobody's answered yet!

Perfectly possible. I bet you don't fit 500V batteries in your IR meter!

 

[DuaneMHunt1976]

I've put my proving unit down some where and can't find it.
But was told you can also prove the unit is working on the incoming source

 

[Dave OCD]

I think somebody nicked mine, but I can't prove it.

 

[edexlab]

Perfectly possible. I bet you don't fit 500V batteries in your IR meter! [emoji14]

Yes fair enough you've got me there, it could be done, but I suspect the unit would be a bit bigger than it is, and wouldn't allow too many tests !
But the point was that it's not a self proving device in the sense that it produces voltages in its test range




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[VoltzElectrical]

a licked finger flicked over the offending cable is proof. :troll:

 

[DPG]

I've put my proving unit down some where and can't find it.
But was told you can also prove the unit is working on the incoming source

You can indeed if you have a live still available after switching off. Daz

 

[davesparks]

But was told you can also prove the unit is working on the incoming source

No sh*t Sherlock!

 

[davesparks]

I would like to know exactly what the self test function actually did before trusting it.

I use the DiLog two pole tester, because I always have and am familiar with it. I've tried other ones but haven't yet got on so well with any of them.

I think the problem here is the one which plagues the industry, and the wider community at times. A lack of understanding, or care for the background information/knowledge. There seems to be a general lack of interest in anything much more than doing the minimum necessary, trusting everything your told without thinking about it, and then going home on time.




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[Andy78]

You can indeed if you have a live still available after switching off. Daz

All you need to do is switch back on to reprove, then isolate, then test for dead. Then reprove by switching back on. Then..... err, isolate and test for dead. Then reprove by, ummm... switching back on.

It's all coming back to me now. I got stuck like this for 6 hours once and had to ring my mate to go and buy me a proving unit.

 

[DPG]

No sh*t Sherlock!

Lovely.