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Replacing Earth Leakage Clamp Meter

ietmgreen
I am looking at the Megger DCM305E Earth Leakage Clamp Meter.

For general domestic fault tracing.

Has anyone got opinions on this meter or a better alternative?

Regards,

Mike.
  • 0
    https://youtu.be/XTUUijDclWk

    For simple domestics, some may scoff at this one but it's calibrated and reasonably priced.
  • 0
    Avoid the TIS 560. Its ranges are 60A, 20mA, 2mA - so if you have a leakage current of 21mA say, then on the 20mA setting it's out of range, while on the 60A setting it displays as 0.1A (maybe).  I.e. it can't accurately display leakage currents usefully in the region where RCDs might be tripping.
  • 0
    The UNI-T UT210 /(UT210E) has a range of 2 Amps max. with a resolution of 1mA. Also a range up to  20 Amps with a resolution of 10mA, plus a 100 Amp range of A.C. current. It also has other functions.


    I have no connection with the makers.


    Z.
  • 0

    Farmboy:
    https://youtu.be/XTUUijDclWk

    For simple domestics, some may scoff at this one but it's calibrated and reasonably priced.




    At £59 (or £74 calibrated), this looks good. By comparison the Megger is on special offer at £194+£50 calibration.

    Have you got an AMECaL ST-9810 in your toolbox?

    Regards,

    Mike.

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    I have one of these little clamp meters,  or at least a re-badge of the same design and after a rather silly  experiment with a DC welder supply I need to do something to degauss the poles, as the zero offset is a bit poor, but perfectly fine for differential tests. Certainly  for following L-N imbalances and 10mA or so sort of currents walking off down the antenna cable and so on it is very handy. Can also be used to pair up singles - where you have a tangle of neutrals and do not wish to cut the wrong one - the one that reads the same as the live circuit you are about to isolate and work on is the right one. Even if it cannot narrow it down to one, it gets you to a much reduced range of search.
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    I have the the DCM305E and can't fault it. What influenced my decision as this review from John Peckham on the old forum.

    As a well known test equipment nut I have a battery of clamp meters. I am having treatment for this chronic illness so if you would like to send a bid was of cash it will help with my treatment and long term recovery! 


    For ordinary clamp meters any of the big 3 will do Megger, Fluke or Kewtech. Just make sure you get one with a True RMS function so you can see the 50HZ current and switch to wide band to see the harmonic current. 


    The most useful mini earth leakage clamp meter is the Megger DCM 300E because it is thin small jaws and can get around conductors in awkward places but on the downside you cant switch to True RMS. he jaws on this one are around 40mm diameter. 


    Next up in the dinky range is the new Megger DCM305E also with 40mm jaws but they are slightly thicker but you can do a 50Hz to wide band compare. Auto ranging and goes way down to sub 1mA (0.001mA) but in the power world not that useful. So a good all round clamp meter. 


    Next my trusty old Robin K2413F switchable between 50Hz and wide band . 70mm jaws for getting around big groups of cables but sometimes difficult to get in to tight spaces. No longer made so command a good price second hand. Kewtech who came out of the Robin stable when it ceased to exist do the same instrument re-badged at a tasty price. 


    Then my Martindale CM100 which has a current loop which is great for getting around a group of large 3 phase and neutral conductors that are widely spaced. True RMS so it can see harmonics. Resolution only down to 10mA which is fine for big distribution circuits, you can wrap the loop around the conductors twice to have the sensitivity. 


    All of the above earth leakage clamp meters will work as an ordinary high current clamp meter up to several hundred amps. 


    If I needed to buy a new earth leakage clamp meter to take to a desert island I would ask Kirsty for 2, and they would be the Megger DCM 305E and the Kyoritsu KEW 2413F from Kewtech for the big jaws. I would take Kirsty as my luxury item. 


    For my book it would have to be BS7671 but to quote Captain Black Adder, " perhaps with a Harrods Lingerie catalog tucked discreetly between the covers". 




    https://www2.theiet.org/forums/forum/messageview.cfm?catid=205&threadid=104770&highlight_key=y&keyword1=DCM305E


  • 0
    For simple fault tracing, is there any point in paying for calibration on a brand new earth leakage clamp meter?

    Regards,

    Mike.
  • 0
    Probably very little - usually you need to know either if things are equal, or more or less than the last thing you measured. Or maybe you need to test if it is damaged after an unfortunate sequence of events.  Normally a fault that means my amp is bigger than your amp is not a realistic failure mode.

    If you have another amp meter of any kind you can put them in the same circuit side by side and see how much they differ. A bit of last digit fruit machining on any digital device is quite normal. If it is your only meter, then maybe cal becomes more important, but otherwise just sanity check it against another known good from time to time.

  • 0

    mapj1:

    If you have another amp meter of any kind you can put them in the same circuit side by side and see how much they differ. A bit of last digit fruit machining on any digital device is quite normal. If it is your only meter, then maybe cal becomes more important, but otherwise just sanity check it against another known good from time to time.

     




    What about a sanity check  in conjunction with a RCD tester set at i/2  NoTrip? 

    My tester is a Megger RCDT320 so I could use 10/2 Milliamps, 30/2 Milliamps ?

    Regards,

    Mike.

  • 0
    yes, probably - but caution that some meters terminate the test current, (certainly on the higher ranges) if the supply is not disconnected  within a short time to avoid danger - which may not give time for the ammeter under test  to finish its cycle of Analog to digital conversion.

    If your RCD tester is one of those then it may be easier to have some known load of known resistance and some known voltage, once upon a time I'd have said a 60W light bulb is ~ 1/4A when hot, but nowadays filament lamps are the rarity, and low current resistive loads are rare and inductive things like motors and transformers are messy because the current and voltage are not in step so the wattage and the current are not simply related by I=P/V.

    Equally mains rated resistors are quite cheap.  10k wirewound will give 23ma at 230V, for example. (but get very hot dissipating 5 watts for more than a couple of minutes at a time)   A few in series / parallel combinations in a suitable enclosure can make a home calibration rig. (Resist any temptation to consider choc bloc screwed to a bit of old floorboard as a permanent assembly.)

    Or a cheap multimeter with an amps range that is rather less bashed around than the working one..

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