Earth leakage clamp meter

[Megavolt]

Hi all

Got the below today.

Dilog DL6507. Buy online or call

Can see the massive benefit of these meters but never used one before. After doing some research some people seem to say clamp both tails and overs say clamp the earth.

What do you think is best and can you advise any tips with using one or false reading to look out for.

Thanks

 

[spark 68]

I prefer clamping both of the tails, as this will show the leakage present in the installation.

Clamping the Earth can lead to misleading imported readings on TNC-S supplies where it is common to find tens' if not hundreds of mA of circulating earth currents sloshing around from other users of the network.

 

[Megavolt]

Thank you spark 68. I have a job tomorrow that has nuisance rcd tripping so I will have a play with it there.

 

[Marvo]

I've seen a lot of good reports on this forum about the Dilog.

 

[a-z electrics]

I bought the Metrel Tek775 mini leakage clamp tester at the Elex show today as I thought it would be handy to have one.. it costs £40 cash total!! anyone else used one? what are they like?

 

[Tim]

I bought the Metrel Tek775 mini leakage clamp tester at the Elex show today as I thought it would be handy to have one.. it costs £40 cash total!! anyone else used one? what are they like?

Is it any good? its the cheapest earth leakage meter ive seen and wondered if that is reflected in the quality

 

[Engineer54]

Is it any good? its the cheapest earth leakage meter ive seen and wondered if that is reflected in the quality

The resolution is pants, for an earth leakage tester, and why it's probably so cheap!! The Dilog is a far better buy all round!!

 

[telectrix]

The resolution is pants, for an earth leakage tester, and why it's probably so cheap!! The Dilog is a far better buy all round!!

why do you need a resolution better than 1mA when you are looking for leakage in the range 1mA upwards to 30mA or 100mA?

 

[Marvo]

I think the better resolution would help to see if there is an upward or downward trend and the accuracy probably wouldn't be too hot at the low end of the scale so if you're checking a lot of individual appliances each with a small amount of leakage then the results may not be too accurate especially if you're adding them up and compounding the errors. I would pay the extra but I'm sure the lower res tester would be very usable if you understand the limitations and perfectly fine for global leakage testing, I suppose it depends mostly on budget.

 

[Engineer54]

I think the better resolution would help to see if there is an upward or downward trend and the accuracy probably wouldn't be too hot at the low end of the scale so if you're checking a lot of individual appliances each with a small amount of leakage then the results may not be too accurate especially if you're adding them up and compounding the errors. I would pay the extra but I'm sure the lower res tester would be very usable if you understand the limitations and perfectly fine for global leakage testing, I suppose it depends mostly on budget.

Couldn't of put it better, ...lol!! Plus i wouldn't be putting too much faith in a 40 quid leakage tester. If you need one (and in this day of reliance on RCD's you do...) far better to spend the extra and have a unit that can cover most, if not all of the likely situations you may encounter..

 

[Tim]

So the concencus is buy the dialog then. Looks like im getting a new gadget.

 

[Engineer54]

So the concencus is buy the dialog then. Looks like im getting a new gadget.

That, or the TM-EL9809 Earth Leakage Clamp Meter, which is a re-badged Dilog DL 6507!! You can get a 5% forum discount from the forum sponsor at testmeter.co.uk

 

[Tim]

That, or the TM-EL9809 Earth Leakage Clamp Meter, which is a re-badged Dilog DL 6507!! You can get a 5% forum discount from the forum sponsor at testmeter.co.uk

I forgot about that one, ive seen good reviews about it. And its cheaper than the dilog branded one.

Cheers,
Tim

 

[Outspoken]

That, or the TM-EL9809 Earth Leakage Clamp Meter, which is a re-badged Dilog DL 6507!! You can get a 5% forum discount from the forum sponsor at testmeter.co.uk

That's what I use, looked at Meggar, Kewtechnic and seaward units, but they are 2-5 times the price of the TM and it does the same job...good kit.

 

[DJ Ovengloves]

I'd post this in the trainee section if I had access (but I don't). I understand on the basics on why the "circulating earth currents" are there, but not fully grasping why they are not dangerous and not corresponding to a shock hazard off bonded metalwork etc.

In the spirit of the forum, I don't expect to be spoon fed the answer, but if someone could start me on the right track I'd be massively grateful.

I prefer clamping both of the tails, as this will show the leakage present in the installation.

Clamping the Earth can lead to misleading imported readings on TNC-S supplies where it is common to find tens' if not hundreds of mA of circulating earth currents sloshing around from other users of the network.

 

[a-z electrics]

The TEK775 has a resolution of 100microamps (ie 0.1 mA) on the 200mA range with a 5%+/- accuracy. I didnt think this was bad for general domestic use but I would be happy to be overruled by our more experienced members.. I guess like anything else, you get what you pay for.. if you need greater accuracy then you pay more.

 

[44ALLAN]

I'd post this in the trainee section if I had access (but I don't). I understand on the basics on why the "circulating earth currents" are there, but not fully grasping why they are not dangerous and not corresponding to a shock hazard off bonded metalwork etc.

In the spirit of the forum, I don't expect to be spoon fed the answer, but if someone could start me on the right track I'd be massively grateful.

DJ..................you have almost answered the question yourself mate...........think about it.
Bonded metalwork/touch voltages/extraneous parts.

Also..............they(currents) are not only dangerous but lethal.............don't ever think differently mate.

 

[DJ Ovengloves]

Thanks Allan.

I understand why in the present configuration there is no shock as the current is flowing straight to Earth via the main Earth bond and Main Equipotential bonding (mainly the Gas according to my clamp meter). I was / am struggling on what would happen if I was stupid enough to remove the Bonding and Earth cables - for instance, would class one fixtures become live?

Anyhoo, after a bit more of a thought time, this is what I think is happening.

Due to the nature of PME, it's common for these Circulating Earth Currents that are present on the local "PME network" (sorry, I don't know the real term) to "enter" the installation as electric is lazy and can see nice and easy return path back to Earth. In the Event the main Earth and Bonding being removed within the installation, the Circulating Earth Currents will simply sod off somewhere else with a better path to Earth (hence the need for "Protective Multiple Earthing" for TNC-S, to ensure there's always and "easy path" for these currents and broken DNO Neutral etc).

Does that seem plausible / make sense / correct?

DJ..................you have almost answered the question yourself mate...........think about it.
Bonded metalwork/touch voltages/extraneous parts.

Also..............they(currents) are not only dangerous but lethal.............don't ever think differently mate.

 

[44ALLAN]

Bit early for me all that lot lol'
Still got a nice 'real ale' head on mate

"I was / am struggling on what would happen if I was stupid enough to remove the Bonding and Earth cables - for instance,"

Basic here mate and you work the rest out...................

Remove earthing............nowhere for fault current(or circulating current) to go.
Remove bonding..............introducing extraneous parts and dangerous touch voltages between equipment and metalwork ( no equipotential zone).

I should read that back before posting it in case I've dropped a 'cod' but I'm sure someone will correct it for me lol

Back to bed ...................zzzzzzzzzzzz