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Type A rcd . EICR coding ? etc

aligarjon
Hi Guys.   Not been on for a long time, just had a bit of a search and couldn't really find anything so thought i would ask and see what you all thought.


1.  Are we or will we be coding type AC rcd's if there are LED's or induction hobs, lots of electronics  etc  present.

2. How much DC leakage does it actually take to saturate an rcd and cause  problem?

3. How much does a standard LED lamp or induction hob  leak ?

If we test an AC RCD with no load and it's fine then re-test it with all LED lights, induction hobs etc turned on and it operates correctly could we then say that it is ok with a note on EICR  OR EIC if installing any of the above.  


Obviously also on an EICR if the RCD then doesn't operate with it all on it becomes a C2 ?


Any thoughts



Gary
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    I have spent a couple of hours yesterday experimenting with RCDs, rectifiers, and various degrees of leakage from the rectifier DC to Earth. The interesting effect is that the leakage seems to cause an increase in trip time, rather than a failure to trip when using my MFT to test. A different RCD tester shows much less effect although they both give similar results with a normal unloaded circuit and RCD. I am using a 1kW lamp load on the rectifier output, so the RCD transformer is actually having to do some work, rather than the unloaded condition. This is an attempt to demonstrate a real circuit rather than the unusual test condition of zero load.

    Well done that man!

    5k resistance increases trip time to a second or so, but does no prevent a trip.

    Although for additional protection 1s is a lifetime...

    Of course, with most MFT it's perhaps not possible to generate a fault of negligible impedance (resulting in the machine recording a trip time) downstream of the rectifier's output?

    I presumed Dave had the MFT connected to the a.c. supply side (emulating the situation where additional protection is needed on the cables supplying the boiler) rather than on the d.c. side which had a fixed 5k (or whatever) fault.

       - Andy.
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  • 0
    I have spent a couple of hours yesterday experimenting with RCDs, rectifiers, and various degrees of leakage from the rectifier DC to Earth. The interesting effect is that the leakage seems to cause an increase in trip time, rather than a failure to trip when using my MFT to test. A different RCD tester shows much less effect although they both give similar results with a normal unloaded circuit and RCD. I am using a 1kW lamp load on the rectifier output, so the RCD transformer is actually having to do some work, rather than the unloaded condition. This is an attempt to demonstrate a real circuit rather than the unusual test condition of zero load.

    Well done that man!

    5k resistance increases trip time to a second or so, but does no prevent a trip.

    Although for additional protection 1s is a lifetime...

    Of course, with most MFT it's perhaps not possible to generate a fault of negligible impedance (resulting in the machine recording a trip time) downstream of the rectifier's output?

    I presumed Dave had the MFT connected to the a.c. supply side (emulating the situation where additional protection is needed on the cables supplying the boiler) rather than on the d.c. side which had a fixed 5k (or whatever) fault.

       - Andy.
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