RCBO not restting

[sparkside1]

Hi all

Have a problem with a Wylex 32A Type C RCBO that has tripped to a utility room and heating plant room to a west London mid terraced house.
It will not reset even with all loads removed. I tried swapping the line and neutral conductors to an adjacent same rated RCBO and the same happened. I tested the ring between L-N at the utility sockets and incoming spur to the plant room and was 0.42 ohms. I only had time for a quick look on xmas eve and will return on Monday to carry out further tests. But not having had many issues with RCBO's I need some advice on how to test these devices properly and what the possible causes could be. There is no history on this fault as the property is vacant and the problem miraculously appeared!

Cheers

 

[Plonker 3]

What were the test results for 1x and 5x tests on the RCBO?

Althogh it sounds like you have a faulty circuit. How did you "remove all loads" before attempting to reset it?

 

[Darkwood]

List your tests and results... not sure what you have been testing for so far...

Do you understand the theory behind rcbo's tripping - this is your first step to fault finding on them and doing the correct sequence of tests.
Have you performed any insulations checks to earth?
You say all the loads removed ....are you sure??? Sw/f spurs isolated etc etc.

We are happy to help but please help us and show you have carried out the correct testing procedures and give results then we can see any irregularities and advice thus.

 

[telectrix]

first thing is to prove the RCBO. will it reset with the outgoing cables dissed? if so, then test it on x1 and x5 and ramp it. then test your circuit. the RCBO could be tripping on overload as opposed to leakage.

 

[Darkwood]

What were the test results for 1x and 5x tests on the RCBO?

Althogh it sounds like you have a faulty circuit. How did you "remove all loads" before attempting to reset it?

I assume if it won't reset then he won't be able to do any live tests...:tree: unless you of course mean disconnection of the circuit....Im unsure the OP has done half the testing required to resolve this.

 

[Plonker 3]

I assume if it won't reset then he won't be able to do any live tests...:tree:

Then it must be a faulty RCBO as the OP has alread stated he has tested the ring between L-N and got a reading of 0.42 although I am unsure exactly what they have tested.

 

[telectrix]

if he's got 0.42 ohms across L and N that's 540A. no wonder it's tripping.

 

[Darkwood]

Then it must be a faulty RCBO as the OP has alread stated he has tested the ring between L-N and got a reading of 0.42 although I am unsure exactly what they have tested.

Yep edited my last comment ...OP is very vague and what is 0.42ohms if he cannot power the circuit then assume he's measuring resistance of the possible ring... again a bit of a disjointed opening posts that leads to more questions then answers.... think OP needs to reply first on this one.

 

[Plonker 3]

Sounds loke another one of those that goes in, is unsure what to do so thinks the internet will reslove it for them.

 

[TJ Anderson]

Then it must be a faulty RCBO as the OP has alread stated he has tested the ring between L-N and got a reading of 0.42 although I am unsure exactly what they have tested.

It sounds like he has a short on the circuit (0.42 L-N).

 

[Plonker 3]

Well we wont know until the OP returns with more info.

 

[Darkwood]

It sounds like he has a short on the circuit (0.42 L-N).

If he's measuring O.42 L-N then this is not a short circuit par se' , any inductive device may give a false reading like say a motor or choke which can look like a fault, so until we have a response from the OP we are all just taking pot shots here.

We need to know clearly what steps he has taken, what tests he has done and what order with results to boot, without them we can only advise to go back and do the correct sequence of tests.

 

[D Skelton]

Sounds loke another one of those that goes in, is unsure what to do so thinks the internet will reslove it for them.

He's right thought isn't he?!

You lot are almost falling over yourselves to help this bungling fault finder with his lack of knowledge.

This fella is being PAID as an electrician, to find a simple fault, and his first port of call is to ask others?!

This whole situation would actually be funny, if it wasn't so sad!

 

[Darkwood]

The OP was viewing the post a few minutes ago but is no longer so I think the fact he hasn't responded brings this thread to an end until he decides to... Hopefully he's going to pop back to the job and re-test

 

[guest119]

There is no point in advising the op how to proqure the test results if he has no clue how to interpret them.
The first response should have been who are you and what is your quals and capability. Thereafter advising accordingly.