Rcd trip current

[schoe]

Hi all can anyone tell me the unacceptable trip current for a30ma rcd. I tested one on fri and the trip current was 24ma but i can't find anything in the regs to state what the minimum trip current is before its classed as nuisance tripping.

If anyone could explain how to carry out a ramp test as well I would really appreciate it,

Thanks once again

Chris

 

[leesturgess]

what tester do you have?

 

[schoe]

A Fluke 1653b

 

[Guest123]

24mA is about right for a 30mA RCD.

Anything below the 0.5xIdN (15mA) would be classed as nuisance tripping.

 

[schoe]

Thanks Lenny, what does the 0.5 x ldn mean, I've seen it but don't really understand it? Thanks

 

[telectrix]

the Idn is the rated trip current ( 30mA ). as you know, RCDs should not trip at x 1/2 Idn. i.e 15mA.

 

[Guest123]

Thanks Lenny, what does the 0.5 x ldn mean, I've seen it but don't really understand it? Thanks

When testing a 30mA RCD for instance, we are required to test at 0.5xIdN, 1xIdN & 5xIdN which equates to 15mA (30x0.5) 30mA (30x1) & 150mA (30x5)

IdN is the rated operating current of an RCD.

 

[tony mc]

Hi Schoe

When carrying out a ramp test set you meter to the ramp test mode and make sure you have selected the 30mA range (Im not sure how its done on your fluke ) press the test button and the meter will start off by putting 15mA in and then increasing normally with new meters 1mA until it trips and the reading on your screen is the current that it has tripped at.

Have a look at page 91 of the on site guide for a little info on RCD's and test procedures!