Whats this mean on a rcd test

[davesparks]

What evidence can you find to say it has to be done your way?

Just think about it for a minute!
What are you testing?
Why are you testing it?
What effect will a less than perfect IR have on the test?
Could the capacitance of the cables have an effect on the test?

What would be the implications of the above if they did affect the test?

 

[ruston]

it's in GN3 . Not a clear pic , but you will get the gist of what Dave is saying.

 

[Maxstone89]

It doesn't preclude another test method thought.

 

[ruston]

I know , I was just showing you where it was written.

 

[Midwest]

Then you are not carrying out the test correctly!
RCD tests should be carried out at the outgoing terminals of the RCD with the outgoing conductors disconnected.

Perhaps you should revise your test procedures a bit before carrying out any more testing.

I understand your hypothesis for testing an RCD (i.e. just testing the RCD only), but how do you do that in the case of a dual RCD CU, without having to deconstruct the bus bars etc? You would also be carrying out an unnecessary live test, with the CU cover removed, when the test can be carried out at a socket without exposure to live parts, unless I'm not understanding you correctly. Why would manufacturers supply such test leads?

 

[davesparks]

I understand your hypothesis for testing an RCD (i.e. just testing the RCD only), but how do you do that in the case of a dual RCD CU, without having to deconstruct the bus bars etc? You would also be carrying out an unnecessary live test, with the CU cover removed, when the test can be carried out at a socket without exposure to live parts, unless I'm not understanding you correctly. Why would manufacturers supply such test leads?

In a CU the outgoing ocpds can be switched off to disconnect the outgoing circuits then just drop the link from The RCD to the N bar and you have the RCD suitably disconnected.

Having the outgoing circuits connected could bias the RCD to trip at lower current than if it was tested in isolation. If the outgoing circuits were to have say 10mA total leakage on them and the RCD was tripping at 38mA instead of the required <30mA then it would pass the tests with the outgoing circuits connected but not with them disconnected.

A competant person carrying out the tests at the cu following safe working procedures will be at far less risk than the unsuspecting user of the installation who suffers a fatal shock because their RCD was not tripping at the right current.

 

[trev]

I know , I was just showing you where it was written.

Yes it does, the bit where it said "the test should be conducted at........."
Nice to see somethings never change on here guys.

 

[davesparks]

Hi Trev
I take it they've revoked your excommunication order!

 

[trev]

The excommunication order that I made mate

 

[GMES]

Trev is always welcome and it is good to see you back matey I and a lot of others have missed you now can you put these silly sods straight about testing rcd's in the way only you can:rofl: