how to test 100 mA rcd

[brucelee]

hi everyone
could someone please explain how to carry out a test on a 100 mA rcd as i am doing a 2391 course at minute and i have come across this question, I understand that i set my megger to 100mA on the appropriate dial and carry out half rated trip and then 1x on both half cycles and then 5x on both half cycles but where do i carry out the test anybody help i have tried looking it up cheers

 

[pevvers]

There's not actually any requirement in BS7671:2008 to test anything other than 30mA and below (it may actually be only 30mA, but it's late and I'm not looking through my regs now!) on the 5x setting. But you would test it on the load side of the RCD at the board, with all loads disconnected.

 

[sparkdog]

I don't think you would do a 5x test on a 100 ma RCD see GN3 page 52 2.7.15.

 

[ian.settle1]

I don't think you would do a 5x test on a 100 ma RCD see GN3 page 52 2.7.15.

You are correct the x5 test is only done RCDs up to and including 30mA

 

[Monkey1984]

That question comes up alot in 2391 exams. Its important you remember to only test 1x and write down the 5x test is not performed on 100mA RCDs.

 

[ian.settle1]

That question comes up alot in 2391 exams. Its important you remember to only test 1x and write down the 5x test is not performed on 100mA RCDs.

And don't forget that it is tested twice at 0 and 180 on each setting and the highest is recorded

 

[brucelee]

cheers to all,
the reason i asked this question is i am doing the 2391 course at the minute. I have had this question on a sample paper i have got. this was a answer i didnt know and couldnt find so thanks again there is a few other questions i have if any body would like to give me advice on the answer and where to find it in regs
the question for above was as i guess u all alredy know is
a 100mA general purpose rcd to bs en 61008 is to be tested to ensure it operates within specifications. State the
a). value of the two current tests
b). maximum operating time when using the larger current
so from your answers, i only test 1x at both half cycles 0&180. do i not do half times rated current at 50mA at both half cycles and no trip
so for answers to above i would state the test current values as 100mA and 100mA or 50mA & 100mA and the max operating time wud be 300ms is that correct.
cheers for help as i need all i can get.

 

[Steve D]

That's right - the 5x test is for additional protection only. a 100mA RCD is not used for additional protection so you just test 1/2x and 1x.

100mA general purpose rcd to bs en 61008 is to be tested to ensure it operates within specifications. State the
a). value of the two current tests
b). maximum operating time when using the larger current

Hiya pal

a) 50mA & 100mA (to be tested on both halves of the cycle)
b) max 300ms for a general purpose RCD to BSEN 61008

 

[SirKit Breaker]

You would carry out the test with your test leads connected to earth rail, and Live and Neutral on the load side of the RCD itself.

Cheers.........Howard

 

[brucelee]

Thanks guys
i have been looking for this answer in all books i have and couldnt find it. As i said its for a sample 2391 question you all have been extremely helpful since joining this site. I am taking a 2391 course evenings at bury college for 8 week 1 day a week. I have been reding writing and doing sample tests for last 2 month or so there is a lot to learn but hopefully im getting there. i have a few more questions which i will post there are only a few that i am having difficulty finding. once again thanks to all. so RCDs over 30mA are not used for additional protection. Am i correct in thinking a 100mA RCD is only used for protection of socket outlets over 32A any info and advice always welcome thanks

 

[pevvers]

Normally 100mA RCD's are for protection against earth faults in TT systems. There are other applications that I can think that they would be used for, but this is the main one...

 

[brucelee]

cheers mate and to all who have posted the only bit of info i could find was 100mA for socket outlets over 32A in agricultural installations . so cheers guys for all the help

 

[pevvers]

cheers mate and to all who have posted the only bit of info i could find was 100mA for socket outlets over 32A in agricultural installations . so cheers guys for all the help

And thanks to you for that bit too, as that is something that I have never heard of!

But then again I don't do much agricultural work living and working in London.... Horses for courses and all that,

 

[Mark2009]

hi everyone
could someone please explain how to carry out a test on a 100 mA rcd as i am doing a 2391 course at minute and i have come across this question, I understand that i set my megger to 100mA on the appropriate dial and carry out half rated trip and then 1x on both half cycles and then 5x on both half cycles but where do i carry out the test anybody help i have tried looking it up cheers

Hi
Download this www.230volts.org.uk/1.zip

thanks

 

[brucelee]

Hi
Download this www.230volts.org.uk/1.zip

thanks

cheers mate tried the link but it doesnt seem to work i will try it in google