48.3ms x 1 rccb | on ElectriciansForums

Discuss 48.3ms x 1 rccb in the Periodic Inspection Reporting & Certification area at ElectriciansForums.net

It's interesting considering what the code would be had it been an issue.
I think C2 is right but it did make me briefly wonder - if it was additional protection for RFC, entirely indoors, and it's only a C3 if you don't have it in the first place, is it C2 if you have it and it doesn't work properly? I decided yes, but mainly because it will never get fixed as a C3.
On the other hand if it was an RCD incomer on a TT system and was slower than 200ms then no question.
 
So with ALL other parameters being satisfied, ie earth loop and disconnection times for the type of protective device. Your saying that a device used for additional protection is potentially dangerous because its tripping time is slightly above spec ie Code 2 ?? or should you consider Code 3 as being a more accurate assessment ??
Of course a TT system just makes your choice easier, Interesting ??
 
So with ALL other parameters being satisfied, ie earth loop and disconnection times for the type of protective device. Your saying that a device used for additional protection is potentially dangerous because its tripping time is slightly above spec ie Code 2 ?? or should you consider Code 3 as being a more accurate assessment ??
Of course a TT system just makes your choice easier, Interesting ??
It is actually quite hard and as you imply having something there and being a shade slower is safer than not having something there (C3), making C2 illogical on one level.
I'd actually prefer not to code it at all! Most EICR's I do have an agreement to fix minor things rather than document them and I think this suits everyone better. I prefer to be using a screwdriver than a pen any day and prefer to explain the issue and get permission to quickly change it than code it!
If I absolutely had to code it I'd reluctantly code it C2 as I'd feel it should be within spec, and I wouldn't be able to foresee whether it might deteriorate further before the property is inspected again. I'd want to be sure it got changed.
 
It is actually quite hard and as you imply having something there and being a shade slower is safer than not having something there (C3), making C2 illogical on one level.
I'd actually prefer not to code it at all! Most EICR's I do have an agreement to fix minor things rather than document them and I think this suits everyone better. I prefer to be using a screwdriver than a pen any day and prefer to explain the issue and get permission to quickly change it than code it!
If I absolutely had to code it I'd reluctantly code it C2 as I'd feel it should be within spec, and I wouldn't be able to foresee whether it might deteriorate further before the property is inspected again. I'd want to be sure it got changed.
So your judgement is its a potentially dangerous defect. So if the installation didn't have the rcd in exactly the same situation would you still say its a potentially dangerous defect. That's the dilemma, and possibly how you would conclude and justify your coding. There is no right or wrong answer, because its about a professional opinion, yours !! Its a thankless task for any sparks, but asking yourself the question can help provide an informed judgement. Some will C3 some will C2 depending on the circumstances. ?
 
So your judgement is its a potentially dangerous defect. So if the installation didn't have the rcd in exactly the same situation would you still say its a potentially dangerous defect. That's the dilemma, and possibly how you would conclude and justify your coding. There is no right or wrong answer, because its about a professional opinion, yours !! Its a thankless task for any sparks, but asking yourself the question can help provide an informed judgement. Some will C3 some will C2 depending on the circumstances. ?
Or to get really technical.
IF IN DOUBT !! COVER YOUR ARSE ?
 
Hi Guys,
With reference to the answers given here, I am going to stick my neck out and say that there is no non compliance in an RCD not tripping within 40 ms @ x5. The regulation 643.8 has a note that states for an RCD used as additional protection:

NOTE: Effectiveness is deemed to have been verified where an RCD meeting the requirements of Regulation 415.1.1
disconnects within 40 ms when tested at a current equal to or higher than five times its rated residual operating current.
I am guessing this is a Hager RCD which are known to often not trip within 40 ms @ x5 and are within BS EN 61008. I believe they needed 250 mA of leakage current to trip within 40 ms. Unless a MFT has a VAR leakage current setting on the RCD test then a Hager RCD of this type probably cannot be tested to see if it conforms?
John (armchair electrician)
 
It's interesting considering what the code would be had it been an issue.
I think C2 is right but it did make me briefly wonder - if it was additional protection for RFC, entirely indoors, and it's only a C3 if you don't have it in the first place, is it C2 if you have it and it doesn't work properly? I decided yes, but mainly because it will never get fixed as a C3.
On the other hand if it was an RCD incomer on a TT system and was slower than 200ms then no question.
I had a similar thought process last year with an RCD on a sub board that failed the test button but passed all other tests perfectly. It was on a circuit that wouldn't necessarily be a C2 if it hadn't been there.

If something is there, then it being 'removed' by it not working in every way it should makes the installation less safe than when it was installed/designed.

Not to mention that people might see an RCD and assume a level of protection that's not there (in between their religious adherence to the 3/6 month testing regime that all householders follow naturally)

Like you, came down on the side of C2 to ensure it was fixed and persuaded the client to replace the main board too.
 
Hi Guys,
With reference to the answers given here, I am going to stick my neck out and say that there is no non compliance in an RCD not tripping within 40 ms @ x5. The regulation 643.8 has a note that states for an RCD used as additional protection:

NOTE: Effectiveness is deemed to have been verified where an RCD meeting the requirements of Regulation 415.1.1
disconnects within 40 ms when tested at a current equal to or higher than five times its rated residual operating current.
I am guessing this is a Hager RCD which are known to often not trip within 40 ms @ x5 and are within BS EN 61008. I believe they needed 250 mA of leakage current to trip within 40 ms. Unless a MFT has a VAR leakage current setting on the RCD test then a Hager RCD of this type probably cannot be tested to see if it conforms?
John (armchair electrician)
Yes you are spot on the Hager’s now often have high trip times but I’m sure that when you alter the mA setting they then give readings which are satisfactory if you google it you will see what they mean and it’s our misjudgment not theirs when we say the trip times are unsatisfactory I had this issue couple of years ago and had to contact Hager and they sent me a clear and definitive response my bad not theirs ?‍♂️?
 

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