MEM RCD Tripping Times

[Ladders]

Hi.

Should the x1 and x5 RCD tripping time test results for the MEM AM1004M RCD 100A 100mA still be as usual? 0.4s etc...
Also if doing a ramp test that should trip in?

Finally, as I think the one I tested is faulty, any ideas where I could get another from?

Thanks.

 

[vernam616]

Without trying to sound awkward but do own a copy of the regs? or have 16th/17th edition?

 

[Marnik]

BS 61008/BS 61009 = 200mS @ 1x - 40mS @ 5x
BS EN 61008/BS EN 61009 = 300mS @ 1x - 40mS @ 5x

 

[Deleted member 26818]

Hi.

Should the x1 and x5 RCD tripping time test results for the MEM AM1004M RCD 100A 100mA still be as usual? 0.4s etc...
Also if doing a ramp test that should trip in?

Finally, as I think the one I tested is faulty, any ideas where I could get another from?

Thanks.

40ms = 0.04s.
It's very unlikely that you will be able to test a 100mA RCD with a standard tester.
Most testers will not produce the required 500mA test current.

 

[Ladders]

So to test a 100mA RCD my Megger 1552 does not cut the mustard. I had a feeling it might be something like that! Doh! The only time I could get it to trip was the x5 test but it took way to long. For the x1 greater than 400 and it would not ramp at all.

 

[platty1005]

The times 5 test is not required for RCD's above 30mA The x5 test is only required if a 30mA or less RCD is used for protecting persons.

 

[Ladders]

Brilliant! I just remembered from your prompt that the Megger has a 500mA setting! So simple with the right help. Thanks.

 

[Ladders]

Actually should it be 100mA setting rather than the 30mA setting I was using as this type of RCD is 100mA? Thanks.

 

[platty1005]

what is the reason you are using a RCD ?
you need to check the Regs or OSG, you should not be taking a 30mA out and replacing with a 100mA without checking full compliance
Off the top of my head requirements are
Sockets 30mA or less
Additional Protection 30mA or less
Bathroom circuits 30mA or less
Concealed cables 30mA or less

100ma plus RCD's are typically used for TT installations when the Zs is too high to achieve disconnection time of 0.2 secs or where additional fire protection is required
Any of the above conditions listed plus a few more I can't remember 30mA or less is required.

PS don't have my Regs to hand so can't remember all requirements