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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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    What I found interesting about the Blakley paper was that the problems with the RCD weren't necessarily related to the load on the circuit the RCD protected. If we had d.c. flowing around our earthing system for any reason then any circuit could be compromised as soon as it developed an earth fault.


    I can't help wondering if things like the d.c. pilot, communication and earth monitoring gubbins on EVSE might be a worry there.

     
    TT installs are a rather special case, and only require a single fault to be dangerous

    I agree it's less likely to be an issue on TN systems - the rectifier arrangement is likely to either limit the fault current to something relatively modest for an earth fault (perhaps a couple of tens of amps) or blow itself to smithereens in short order (ADS after a fashion) - which with a EFLI in the region of an Ohm or so isn't likely to produce a hazardous voltage difference - but still probably not ideal to let it persist. TT will be quite different though - such currents could raise the entire earthing system to very hazardous levels so you really don't want the one device that providing both ADS and supplementary protection to be disabled. I think we have enough TT installations even in the UK for it to be a worry (especially if we've been busy creating new ones for EV charge points). Most manufacturers and of course ENs cover regions where TT is the norm (France and southern Europe for example) so I can see why it's being raised.


       - Andy.
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  • 0
    What I found interesting about the Blakley paper was that the problems with the RCD weren't necessarily related to the load on the circuit the RCD protected. If we had d.c. flowing around our earthing system for any reason then any circuit could be compromised as soon as it developed an earth fault.


    I can't help wondering if things like the d.c. pilot, communication and earth monitoring gubbins on EVSE might be a worry there.

     
    TT installs are a rather special case, and only require a single fault to be dangerous

    I agree it's less likely to be an issue on TN systems - the rectifier arrangement is likely to either limit the fault current to something relatively modest for an earth fault (perhaps a couple of tens of amps) or blow itself to smithereens in short order (ADS after a fashion) - which with a EFLI in the region of an Ohm or so isn't likely to produce a hazardous voltage difference - but still probably not ideal to let it persist. TT will be quite different though - such currents could raise the entire earthing system to very hazardous levels so you really don't want the one device that providing both ADS and supplementary protection to be disabled. I think we have enough TT installations even in the UK for it to be a worry (especially if we've been busy creating new ones for EV charge points). Most manufacturers and of course ENs cover regions where TT is the norm (France and southern Europe for example) so I can see why it's being raised.


       - Andy.
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