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.

 

[DPG]

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.

I think the idea is you can isolate one circuit, but use a still-live circuit for proving. Doh. Daz

 

[Toneyz]

I've got JD with provng unit and other type tester for belling out cables etc.I am shocked these days with to turn up on site these days to help so called electrician to find fault to earth with one,got all the other kit battary dills and big dewalt radio etc no test equipment just turns on electric don't trip out must be ok then.

 

[PEG]

Stienel make some great kit,and i had an early two pole tester as a youth.

It had AC and DC scales,polarity indicator and a "self-test" feature.

This function was always understood to be ONLY a test of the scale indicator LED's,and NOT of the devices ability to detect voltages across that scale.

I am pretty sure the instrument instructions stated this,also.

 

[Brightspark2]

If the voltage indicator has 2 forms of indication, ie sound and visual and is classed as self testing then a proving unit is not necessary.

So I was taught on my 2391 some years ago and I've stuck with that since.

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[davesparks]

If the voltage indicator has 2 forms of indication, ie sound and visual and is classed as self testing then a proving unit is not necessary.

So I was taught on my 2391 some years ago and I've stuck with that since.

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What standard was given as the reference for being classed as self testing?
There's a world of difference between a manufacturer claiming that something is self testing and a self test system which is safe and compliant with a standard.

Personally I wouldn't put my life at risk on the word of a tutor on a course.

 

[davesparks]

Lovely.

He was asking for it

 

[Brightspark2]

What standard was given as the reference for being classed as self testing?
There's a world of difference between a manufacturer claiming that something is self testing and a self test system which is safe and compliant with a standard.

Personally I wouldn't put my life at risk on the word of a tutor on a course.

Depends how your using the word standard Dave.

But confirm with manufacturers data that the unit is self testing, GS38 states that to be complaint, the self test system is listed there as a type of 2 probe tester. This gives compliance with EAWR. A system which is safe and compliant.

But the same can be said for a prooving unit.

What standard was given as reference when advising the use of a prooving unit, theres a world of difference from the manufacturer claiming it works and a system which is safe and compliant such as a known live source.

You see, I imagine there was the same scepticism when prooving units were first introduced.





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[ETO]

As per GN3.

 

[DPG]

If the voltage indicator has 2 forms of indication, ie sound and visual and is classed as self testing then a proving unit is not necessary.

So I was taught on my 2391 some years ago and I've stuck with that since.

Sent from my E5823 using Tapatalk

I don't get that at all. The detection circuit could be faulty, in which case neither the LED or the buzzer would operate. You still need to test it. Daz

 

[Brightspark2]

I don't get that at all. The detection circuit could be faulty, in which case neither the LED or the buzzer would operate. You still need to test it. Daz

Well then you've proved your meter is faulty?.

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[DPG]

No, all you have proved is that either the circuit is dead OR your tester is faulty. Daz

 

[murray2707]

Still got my trusty martindale and proving unit I've had since I was a 1st year apprentice in 2006. Can't go wrong, neons are either on or off

 

[davesparks]

Depends how your using the word standard Dave.

But confirm with manufacturers data that the unit is self testing, GS38 states that to be complaint, the self test system is listed there as a type of 2 probe tester. This gives compliance with EAWR. A system which is safe and compliant.

But the same can be said for a prooving unit.

What standard was given as reference when advising the use of a prooving unit, theres a world of difference from the manufacturer claiming it works and a system which is safe and compliant such as a known live source.

You see, I imagine there was the same scepticism when prooving units were first introduced.





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I man standard in terms of a recognised standard such as a BS or international equivalent.

A proving unit doesn't have the same problem, it is applying a voltage to the test probes and causing the normal indication of a live circuit from the tester. If it doesn't work then it will be obvious.

 

[DPG]

The confusion here I think is that Brightspark is talking of the tester having a self-test function. Yes, it does - short the probes together and all lights and the buzzer will light up/sound. This however is different to using a proving unit or testing the tester on a known live source. My Kewtech has a self-test function, but it still needs to be used with a proving unit for the safe isolation process. Don't confuse the two things. Daz

 

[DuaneMHunt1976]

No sh*t Sherlock!

No pooping in the forum please