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Testing A-type RCD at half times 100m/A ?

aligarjon

I watched a video the other day which mentioned that A-type 30m/A rcd's should be tested at about 54m/A i think it was and that setting your tester to 100m/A and doing a half times test was was acceptable.  Is this correct and where does it come from.

Cheers.  Gary

Parents
  • 0

    That would mean they had really moved the goal-posts then, so that an A type 30mA RCD need not trip at 30mA - EVEN ON A NORMAL AC TEST

    (clearly a higher test current for the un-smoothed DC test is a different matter)

    This would  be  silly given the reason for the choice of a 30mA current is the human shock current/mortality curve to Alternating Current and there have been no corresponding changes to improve the robustness of human physiology in the last few years since the last edition of the regs. Actually if anything the 30mA limit and permitted trip time is already a bit high for comfort, protecting neither the elderly nor the very young, both of whom tend to have higher heart rates and greater shock sensitivity, However there is also a trade off against nuisance tripping.

    I'm very pleased to say that all the A types I have tested so far do in fact trip at 20-25mA, just like the old ones used to.

    Stick with testing all RCDs as if they were AC types at the nominal current (30mA for the instant trip ones) - that should always work as the lowest common denominator.

    I think the maker of that video has misunderstood the intent.

    Mike.

Reply
  • 0

    That would mean they had really moved the goal-posts then, so that an A type 30mA RCD need not trip at 30mA - EVEN ON A NORMAL AC TEST

    (clearly a higher test current for the un-smoothed DC test is a different matter)

    This would  be  silly given the reason for the choice of a 30mA current is the human shock current/mortality curve to Alternating Current and there have been no corresponding changes to improve the robustness of human physiology in the last few years since the last edition of the regs. Actually if anything the 30mA limit and permitted trip time is already a bit high for comfort, protecting neither the elderly nor the very young, both of whom tend to have higher heart rates and greater shock sensitivity, However there is also a trade off against nuisance tripping.

    I'm very pleased to say that all the A types I have tested so far do in fact trip at 20-25mA, just like the old ones used to.

    Stick with testing all RCDs as if they were AC types at the nominal current (30mA for the instant trip ones) - that should always work as the lowest common denominator.

    I think the maker of that video has misunderstood the intent.

    Mike.

Children
  • 0 in reply to mapj1

    "there have been no corresponding changes to improve the robustness of human physiology in the last few years since the last edition of the regs" Laughing

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