Whats this mean on a rcd test

[davesparks]

Urh as your closer to the board

I still don't get it? Your standing at the board if you are following the correct procedure.
Even if you are doing it at a socket you just set the tester, walk to the board, reset each time it trips, then go back to the tester and review the results.
What's the problem?

 

[trev]

I always do at nearest socket too, as this also allows for resting rcd easily,

If the zs is fine then doing the test at a socket will give the same result, if it doesn't work at the socket , then how would the rcd protect you in the correct times at the socket if their was a fault at that socket

I know I said I was out of this but I got the notification so here I am again. In one breath you're saying test at an extremity of the circuit and in the next you're at the nearest socket. Howay mate, make your mind up.
Incidentally, at the far end of a radial circuit how much of a pain in the arse is it to do it your way? Hit test button, no trip, trip on 1 x, wander over to reset, trip at 180 degrees, wander over to reset, same with 5 x.

 

[Maxstone89]

Auto setting so you just stay at rcd and reset each time

(Modern testers i guess)

 

[davesparks]

I always do at nearest socket too, as this also allows for resting rcd easily,

If the zs is fine then doing the test at a socket will give the same result, if it doesn't work at the socket , then how would the rcd protect you in the correct times at the socket if their was a fault at that socket

As I explained earlier, it is not that it may not trip when tested at the socket. The problem is that an earth leakage of a couple of milli amps or the effect of cable capacitance may bias an RCD to trip at a lower current or faster than it would if tested in isolation. Then the RCD will pass your test but not be operating within the required specification. If this RCD is then called upon to save someone's life then it may not do so.

 

[trev]

And you keep the probes on how exactly? Let's say it's a domestic lighting circuit.
Btw I know all about the auto test function.

 

[newtothis]

He is also testing at a socket with such a short piece of cable that it would make no real difference to the test. Imagine that cable as being a realistic length for a final circuit and work out how it may affect the result.

Yes I see what you mean, thanks for replying.
I've just wandered into this post, TBH I haven't got the level knowledge to agree or disagree with anyone.:smiley2:

Can you clarify if I'm doing it right.
MF tester on RCD
Auto - 30ma selected.(appropriate)
I stick a probe in the top of the closest protected MCB to the RCD
Probe to the N of that circuit and EARTH.

After that I record the readings, do a ramp test, and press the test button.
Signed: Confused of Sussex ! :mickey:

 

[Leesparkykent]

Kurtis I guess as you test at the circuit and not the RCD itself, do you perform the RCD test for/on every circuit and mark each and every result down on your cert?

 

[davesparks]

Yes I see what you mean, thanks for replying.
I've just wandered into this post, TBH I haven't got the level knowledge to agree or disagree with anyone.:smiley2:

Can you clarify if I'm doing it right.
MF tester on RCD
Auto - 30ma selected.(appropriate)
I stick a probe in the top of the closest protected MCB to the RCD
Probe to the N of that circuit and EARTH.

After that I record the readings, do a ramp test, and press the test button.
Signed: Confused of Sussex ! :mickey:

Not quite.

You switch off all MCBs protected by it, and drop the outgoing N connection from the RCD.
Clip on to an earth connection and probes on the outgoing terminals of the RCD with firm contact pressure.
Start the test.
You can remove L and N probes between each test to reset the RCD.

A ramp test is not required as part of formal testing procedure, the 0.5x and 1x tripping time test confirm that the RCD trip current is within spec.

You are correct that you operate the test button after carrying out the tests, not before.

 

[newtothis]

Not quite.

You switch off all MCBs protected by it, and drop the outgoing N connection from the RCD.
Clip on to an earth connection and probes on the outgoing terminals of the RCD with firm contact pressure.
Start the test.
You can remove L and N probes between each test to reset the RCD.

A ramp test is not required as part of formal testing procedure, the 0.5x and 1x tripping time test confirm that the RCD trip current is within spec.

You are correct that you operate the test button after carrying out the tests, not before.

Thanks very much for that, I'll run through it tomorrow.
Was confused because I never touched the rcd before, except to reset and push the test button.

 

[Vitesse]

Thanks very much for that, I'll run through it tomorrow.
Was confused because I never touched the rcd before, except to reset and push the test button.

There is a very good video here on YouTube., that explains testing at the CU. The bloke is a bit posh but a lot of his stuff is very good and he explains it all well.

http://youtu.be/ZaAUg75BR5Y