Earth Leakage Clamp Meter...Why do I need one?

[Midwest]

What I can’t understand is what is the difference between some of the £300-500 dedicated earth clamp meters and £50-100 clamp meters that measures down to single digit milliamperes, and these are not total crap.

I bought a cheapo one, as recommended by a forum member, a TM-EL9809 for £120. Had it two years, in which time I used it once okay. Next time I came to use it, it went wibble and was apparently unrepairable.

So I went to purchase a Megger one, but they were out of stock. So without now; not sure whether its worth the investment. But if you got wads of cash, I can see them being a useful accessory, bit like a laser level.

 

[suffolkspark]

I've not had to use mine too much but once I had an intermittent tripping issue at a property which I couldn't find with IR testing, with the clamp meter around the main earth I could see that with certain parts of their cooker turned on, the leakage rose drastically. touch screen type cooker so wasn't possible to find this one with it dead, and the only other option as somebody else suggested was set an rcd tester to ramp test and work out leakage that way, this is just quicker, its only a £100 dilog that has 1mA resolution

 

[Deleted member 105166]

Unless working in electronics, you're unlikely to need accuracy to greater than 1mA. The meters with a higher top end range are of course also good for current draw measurements, as well as earth leakage, although sometimes the jaws may be too large to work around tight/densely cabled areas, e.g. Megger IClamp. An iFlex or similar device could be better in such cases.

 

[netblindpaul]

I've not had to use mine too much but once I had an intermittent tripping issue at a property which I couldn't find with IR testing, with the clamp meter around the main earth I could see that with certain parts of their cooker turned on, the leakage rose drastically. touch screen type cooker so wasn't possible to find this one with it dead, and the only other option as somebody else suggested was set an rcd tester to ramp test and work out leakage that way, this is just quicker, its only a £100 dilog that has 1mA resolution

Don't clamp the earth connection, you can get false readings.
Clamp both live conductors that way the meter measures what the RCD "sees".

 

[suffolkspark]

Don't clamp the earth connection, you can get false readings.
Clamp both live conductors that way the meter measures what the RCD "sees".

agreed that is best but my little dilog one wont fit around 2x 25mm tails, I still saw a controlled and consistent increase in leakage clamped around the main earth

 

[Marvo]

I actually use one of these, it's not officially sold as an earth leakage clamp meter but it performs well in the >5mA range. It means I don't need to carry two clamp meters unless the DB is over 400A plus the flexible clamp makes it very easy to clamp phase+neutral or 3 phases + neutral without too much manoevering of the conductors.
Chauvin Arnoux MA400D-170 Clamp Meter, Max Current 399.9A ac CAT IV 600 V | P01120575Z | RS Components - https://za.rs-online.com/web/p/clampmeters/7781040/

I have an earth leakage clamp as well for the odd occasion I need to accurately measure a value that's less than 5mA but I probably haven't used it in the last 6 months.

They do several models with higher current ranges and longer Rogowski clamps.
You'll probably find it cheaper in one of the UK based wholesalers.

 

[The Ghost]

Oh yeh they are £45.00 here, how much is R3382.47 in GBP @Marvo is that good £45.00?

 

[123]

It looks like for the time being I'll remain without an earth leakage clamp meter then. I can see in times ahead of RCD everything everywhere that it will have it's uses, but I'm failing to see how spending several hundred quid + annual calibration costs will even see one pay for itself, and it seems that it's not going to be an item that gets much if any use throughout the year.

 

[Deleted member 26818]

It looks like for the time being I'll remain without an earth leakage clamp meter then. I can see in times ahead of RCD everything everywhere that it will have it's uses, but I'm failing to see how spending several hundred quid + annual calibration costs will even see one pay for itself, and it seems that it's not going to be an item that gets much if any use throughout the year.

Not sure it would need calibration.
Perhaps if you were using readings from it to fill in certificates.

 

[Marvo]

Oh yeh they are £45.00 here, how much is R3382.47 in GBP @Marvo is that good £45.00?

Sorry, thought I'd posted a UK link. ZAR3382.47 is about 190 UK Pounds but they're cheaper on the UK website at 130 quid. Try Testmeter for the forum discount Test Meter Discount Code - https://www.test-meter.co.uk/index.php/electricians-forums-discount

 

[The Ghost]

Thanks @Marvo

 

[Midwest]

agreed that is best but my little dilog one wont fit around 2x 25mm tails,

You most be one of the lucky ones, to still have a working dilog earth clamp meter

 

[telectrix]

agreed that is best but my little dilog one wont fit around 2x 25mm tails, I still saw a controlled and consistent increase in leakage clamped around the main earth

i have same problem with mine. clamp won't close round 25mm tails.

 

[Noaksie]

Millamp clamp meter or a good quality multimeter with low milliamp range connect on line with the earth/CPC works well. With the increase in RCD/RCBO protection being required for all circuits in the 18th edition. We will all have more nuisance tripping RCD faults to investigate

 

[a-z electrics]

Excellent educational video.. thanks for sharing that.
I have to say I do own such a clamp meter but have yet to use it in anger.. it's at the bottom of my Spare toolbar somewhere... I Hope!
Circuit isolation, appliance isolation (usually cooker or immersion element) MFT and a bit of logic has always sufficed to date.. but also am aware of the increase in electronic gizmos can have an a cumulative effect.

 

[HandySparks]

Millamp clamp meter or a good quality multimeter with low milliamp range connect on line with the earth/CPC works well...

If I've understood you correctly, powering up an installation with a multimeter in series with a cpc or earthing conductor is a bad idea. If the multimeter internal fuse pops, you lose the earth and the exposed conductive parts are likely to rise to 230V.

 

[123]

I've had the lend of a Megger Earth Leakage Clamp Meter for a few days. Had a play around with it although typically no call outs...until today. Trying to wrap up for holiday a man down and they poured in. A good day to try it out, but my word, it's absolutely useless for everyday fault finding. It was my IR tester all the way. And damp and water ingress each time .

Its not something I think I'll ever need, it may have its uses as RCD everything gets ramped up and into commercial/industrial premises, but I have no use for it currently.

 

[Deleted member 26818]

To be honest, you’d probably only use it for nuisance tripping RCDs. Check how much earth leakage there is on a circuit in normal use.
Another use would be to check whether the loading on a 3 phase installation was out of balance.

 

[sunray]

In my experience 50% of RCD tripping is to an earth other than the CPC and I don't think I've ever put a clamp on an earth cable while looking for such a fault.