Over sensitive RCD, is there a code ?

[pkbristol]

I recently did a PIR, end of last year, the RCD was over sensitive, tripping at 17ma, is there a code for this ?

Code 2 (requires improvement), now i'd say yes this does require improvement, nuisance tripping maybe, but i wouldn't class this as a potential danger.

Code 3 (requires further investigation), well not really, it's an over sensitive RCD, i know that so no need to investigate, i could just change it, (if customer puts hand in pocket).

Thanks, Paul.

 

[Andy™]

there is no requirement for ramp test

and providing it does not trip at 15mA, and required times at 1x & 5x, then tere is nothing wrong with it

 

[pkbristol]

Hi Andy.

That's the point it trips almost immediately, on my megger 1552 on auto RCD test, it does 1/2, 1x then 5x but this rcd was tripping almost immediately, from all circuits which are RCD protected. I did the ramp test just for my own curiosity to see what is was tripping at.

So is there a code for this.

Thanks, Paul.

 

[Andy™]

did you test with all outgoing circuits removed? there may already be some leakage so your test results may be wrong

 

[pkbristol]

No i didn't try that, i did what i usually do, ie, plug megger in at plug sockets, do rcd test, and lighting circuits, do rcd test, then usually i do all the other rcd protected cicuits which are also rcd protected.

When you say all outgoing circuits removed do you mean switch off all breakers ?

Thanks, Paul.

 

[tom1]

try testing at the cu with all breakers off

 

[pkbristol]

Ok, guys, thanks, but as it stands now, it doesn't look like i'll be going back to the house, (owner doesn't want to shell out any more money and there's already a code 2 there anyway, see this thread

http://www.talk.electricianforum.co.uk/question-answer-board/18307-electrical-installation-condition-report-r1-very-high-but-r1-r2-low.html )

what code if any could i give to this RCD.

Thanks, Paul.

 

[tom1]

what were your trip times at X1 and X5

what is the rcd bs number

but any how as andy says if you did not test the rcd in isolation then your results may be inaccurate

 

[Andy™]

Ok, guys, thanks, but as it stands now, it doesn't look like i'll be going back to the house, (owner doesn't want to shell out any more money and there's already a code 2 there anyway, see this threadhttp://www.talk.electricianforum.co.uk/question-answer-board/18307-electrical-installation-condition-report-r1-very-high-but-r1-r2-low.html )

what code if any could i give to this RCD.

Thanks, Paul.

the only code you could give is 3, since you havent established if its a fault with the RCD or an external fault causing your results to be wrong

 

[pkbristol]

what were your trip times at X1 and X5what is the rcd bs number

but any how as andy says if you did not test the rcd in isolation then your results may be inaccurate

RCD has bs4293 written on it. 80A, 30ma. It doesn't trip at 1x and 5x, it trips before it gets to that, i did it on auto and it trips before even the half x, which is why i did the ramp to see what it requires to make it trip.

---------- Post Auto-Merged at 13:27 ---------- Previous post was made at 13:26 ----------

Cheers Andy, code 3 it is then.

Thanks, paul.

 

[green-hornet]

If it is tripping before x1 then its a fault, and would need to be replaced. RCD's should not trip at half. As for the code, you could put it as a 3 because the actual fault has not been established ( within reason ), I would also put all circuits connected to this RCD as a LIM because you can not test the RCD time correctly. The PIR you did should be unsatisfactory and remedial works should be recorded. Remember the PIR is now EICR and the codes have changed slighty in definition.

 

[batty]

I don't think i would code it but the are plenty of places to put comments on certificates. As others have said its probably circuits with poor insulation dragging it down. I would assume new EICR has places for comments.

 

[Sidewinder]

Whilst it should NOT trip at x 1/2, it must be tested correctly, which is at the outgoing terminals of the RCD with all circuits disconnected.

If this is not the case the the test results are invalid and you cannot legitimately code on them.