Testing RCDs and RCBOs

Discussion in 'Electrics UK' started by Gees, 22 Jul 2010.

  1. Gees

    Gees

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    How are these overload devices tested? Or are we just supposed to trust them?
    I saw some reports of fake units with nothing inside them.....just a switch.

    I dont mean the RCD side of things just the overlad side.
     
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  3. Spark123

    Spark123

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    As with an MCB, you just have to trust them.
    As for counterfeit, if you purchase from a reputable place then you shouldn't get stung.
     
  4. flameport

    flameport

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    The fake ones with no insides are easy to detect, as they will weigh virtually nothing.
     
  5. ericmark

    ericmark

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    The RCD of course can be tested both for current and time.

    The MCB in the main we trust as we do the fuse.

    However I have tested MCB's on a caravan site. The supply to site was split phase with 100A per phase about 65 caravans so 3A per caravan but with diversity should get away with 5A per caravan especially as some were empty. However the 100A moulded breaker was tripping. So put 16A plug on a 2Kw fan heater and tried each outlet should hold on 1Kw but trip on 2Kw. And we found people had screwed in the adjustment screw and had swapped 5A for 15A and scrapped the 1 off the reset leaver. However did not find any which did not pass test and had no signs of tampering.

    This was OK with 5A MCB's but as you look at 50A MCB's then really no way to test. Except for weight as any fake ones will likely be lighter than normal and feel of re-set leaver when handling many units it is likely one would realise they are light and the leaver does not feel same as rest.
     
  6. RF Lighting

    RF Lighting

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    [​IMG]
     
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  7. Gees

    Gees

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    Seems a bit "iffy" to me... Trust me guv'ner, It's a gud un...
     
  8. Gees

    Gees

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    how do you control the current? I can see the ammeter and the MCB but what feeds them?
     
  9. RF Lighting

    RF Lighting

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    It's an arc welder. It steps the volts down, so the current goes up.

    There is a something that moves inside the transformer to adjust the current from about 30A to 120A
     
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  11. 1john

    1john

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    out of interest, how did those new style mk breakers fair? i stopped using mk when they introduced those MCB's, they were no where near the quality of the ones with the center switch, or the type before them with the switch at the bottom.
     
  12. RF Lighting

    RF Lighting

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    They seem to work ok.

    Theyre better than electrium ones anyway :LOL:
     
  13. Gees

    Gees

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    Good idea that.. Thank you
     
  14. Taylortwocities

    Taylortwocities

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    Maybe time to take a reset - RCDs and RCBOs are not overload devices...
     
  15. securespark

    securespark

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    Doesn't RCBO stand for

    Residual
    Current
    Breaker with
    Overload

    ??
     
  16. Taylortwocities

    Taylortwocities

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    Whoops :oops:

    I should have put RCDs are not overload devices....
     
  17. EdwardCurrent

    EdwardCurrent

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    :rolleyes: Over 'current' ! :LOL:
    Just like my name ;) .

    Ed
     
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