TT Triping nightmare

[Pazspark]

Hi I have been called to a fault on a house that the rcd trips it is a old barn conversion but all the wiring is about 7 years old the board has a rcd up front covering lights ect then second covering sockets and garage ect.

16th edition

The customer has told me that they have always had triping but it normaly just comes back on then two weeks later trip again but can be reset I was called as this time it could not be reset. When I got there I did the normal unplug appliances ect then with that not working started separating neutrals on each circuit one by one but all still triped then out of the blue after alot of messing around it just reset everything fine then next day the exact happens again have half hour play then resets. Also when you do start trying to reset the rcd the mcbs buzz but then after the messing around everything comes back on with no problem.

I have swaped the rcds and the mcb for the lights really scratching my head now

 

[ProDave]

Disconnect ALL circuits, L and N, and test each circuit individually.

 

[m4tty]

What testing have you done ?

 

[Pazspark]

Hi mate I have done this then reconnected would trip on the ring main so thinnking that was it and leave them out it would then trip on the shower or another circuit

---------- Post Auto-Merged at 09:19 ---------- Previous post was made at 09:18 ----------

All readings are fine I havnt done insulation resistance tho as the client has a lot of cameras

 

[SPECIAL LOCATION]

I have swaped the rcds and the mcb for the lights really scratching my head now

Why have you swapped something that is "I presume" working correctly?

As you will have tested the RCD trip times etc..

By the sounds of it The RCD is fully functional & doing its job..

You need to do more investigation on the circuits it is protecting.

Swapping the RCD is about as logical as me fitting a new petrol tank in my car when it runs out of petrol!!

Wrong fault.. wrong cure...

Old barn..

what sort of symptoms do you think you could get if there were rodents disturbing cables they have chewed insulation off.

Or damp getting into a dodgy outside fitting..

There are loads of possible causes that need investigation. IMHO.

 

[Pazspark]

I swaped the rcds as my testers the first time I turned up were on another van.

Outside lights are not a problem as they are on one circuit with cables removed from the board.

 

[SPECIAL LOCATION]

Hi mate I have done this then reconnected would trip on the ring main so thinnking that was it and leave them out it would then trip on the shower or another circuit---------- Post Auto-Merged at 09:19 ---------- Previous post was made at 09:18 ----------

All readings are fine I havnt done insulation resistance tho as the client has a lot of cameras

headbang

 

[Pazspark]

The rcd test button was also not working

 

[SPECIAL LOCATION]

I swaped the rcds as my testers the first time I turned up were on another van.Outside lights are not a problem as they are on one circuit with cables removed from the board.

why go at all then without the tools??

 

[Pazspark]

As it was 10pm at night for a friend and I didn't Want to disturb my lad who works with me.

---------- Post Auto-Merged at 09:32 ---------- Previous post was made at 09:30 ----------

Mate thanks for the help and all that but asking why I didnt go with the testers ect a 10 at night isn't really helping

 

[martinxxxxxx]

Hi mate I have done this then reconnected would trip on the ring main so thinnking that was it and leave them out it would then trip on the shower or another circuit---------- Post Auto-Merged at 09:19 ---------- Previous post was made at 09:18 ----------

All readings are fine I havnt done insulation resistance tho as the client has a lot of cameras

You won't get anywhere near solving this without doing IR testing. All loads should be removed prior to this testing, that includes camaras - everything. Then test at 250V first, which will avoid damaging anything that you have missed removing from the circuit.

The camaras will not be affacted if they are not powered by this circuit, if induced currents are what is concerning you?

I had a rcbo tripping problem last week and I found that it is not following proper testing procedures that elongate how long you will be looking for the fault in these situations. Go by the book. Disconnect everything and tick off circuit by circuit - common problems are caused by common things - not escoseric ones - well most commonally they are. The only way is to remove all loads and get testing

 

[Revved Up Sparky]

Hi mate I have done this then reconnected would trip on the ring main so thinnking that was it and leave them out it would then trip on the shower or another circuitAll readings are fine I havnt done insulation resistance tho as the client has a lot of cameras

Tell your client that in order to carry out all necessary electrical tests, the cameras need to be isolated/ disconnected from the circuits feeding them.

Correct insulation resistance testing is vital in order to eliminate insulation failure of one or more of the final circuits from the investigation.

(Sorry Martin I did'nt see your post before I submitted mine.... +1)

 

[Pazspark]

True mate I will have to go and do it just weird how it will play up buzzing and tripping for half hour then just reset then do exact same the next time

 

[Revved Up Sparky]

leakage current could be hovering just under the rated tripping current (eg 30ma) and then occasionally going above it to trip RCD. You need to know whether it is a load or one of the circuits.

 

[Pazspark]

Yer I suppose and either the load has a problem or the circuit cabling cheers mate

 

[SPECIAL LOCATION]

As it was 10pm at night for a friend and I didn't Want to disturb my lad who works with me.---------- Post Auto-Merged at 09:32 ---------- Previous post was made at 09:30 ----------

Mate thanks for the help and all that but asking why I didnt go with the testers ect a 10 at night isn't really helping

Well it really isn't much help asking on a forum what the answers are when you have attended site without testers or doing the basic tests "IR"....

I suppose your local garage can fix your car without you having to leave it with them as well??

Tips for ANY RCD fault..

1/ Take RCD tester..

2/ Check trip times (and ramp test)

3/ Do IR tests on relevant circuits..

Simple elementary electrical checks that HAVE TO BE THE FIRST step in the investigation proccess..

Either this is a bit of a weekend wind-up thread...

Or you are working out of your ability.

30ma RCD..

or 100ma front end time delayed RCD are still very small currents that are causing the RCD to operate..

Just swapping stuff..

hoping for the best ..

doing no tests..

then asking on a forum is not the signs of a competent person at work!

Its not a Tripping "Nightmare" more just lazy(or non existent) testing..

Come back with some proper test figures and we may be able to give some more constructive suggestions.

:C

:|

 

[betty swollocks]

^^^ he said it, I was thinking it ^^^

 

[tom1]

neutral eath fault could be the cause,

did you ramp test the rcd

 

[Andy™]

Mate thanks for the help and all that but asking why I didnt go with the testers ect a 10 at night isn't really helping

if your competent, you should be able to easily identify the fault with the use of a test kit. going to a fault finding job without one you may aswell stay at home and not bother. probably just as useful

 

[Doc Hudson]

Hi mate I have done this then reconnected would trip on the ring main so thinnking that was it and leave them out it would then trip on the shower or another circuit---------- Post Auto-Merged at 09:19 ---------- Previous post was made at 09:18 ----------

All readings are fine I havnt done insulation resistance tho as the client has a lot of cameras

Hi I have been called to a fault on a house that the rcd trips it is a old barn conversion but all the wiring is about 7 years old the board has a rcd up front covering lights ect then second covering sockets and garage ect.16th edition

The customer has told me that they have always had triping but it normaly just comes back on then two weeks later trip again but can be reset I was called as this time it could not be reset. When I got there I did the normal unplug appliances ect then with that not working started separating neutrals on each circuit one by one but all still triped then out of the blue after alot of messing around it just reset everything fine then next day the exact happens again have half hour play then resets. Also when you do start trying to reset the rcd the mcbs buzz but then after the messing around everything comes back on with no problem.

I have swaped the rcds and the mcb for the lights really scratching my head now

I swaped the rcds as my testers the first time I turned up were on another van.Outside lights are not a problem as they are on one circuit with cables removed from the board.

The rcd test button was also not working

As it was 10pm at night for a friend and I didn't Want to disturb my lad who works with me.---------- Post Auto-Merged at 09:32 ---------- Previous post was made at 09:30 ----------

Mate thanks for the help and all that but asking why I didnt go with the testers ect a 10 at night isn't really helping

True mate I will have to go and do it just weird how it will play up buzzing and tripping for half hour then just reset then do exact same the next time

Yer I suppose and either the load has a problem or the circuit cabling cheers mate

Welcome to the forum. I am getting confused reading these posts. First of all I got the impression it was an RCD fault, (you didnt say if it was the 100ma or 30ma?), at an unknown customer who has had ongoing problems so you were called out, But then it reads as though you have been to site multiple times once swapping the RCD's (which one or both) then back because of continuing problems, but you still haven't done the basic checks or taken correct test equipment? Are you a student without access to the correct equipment? Your posts then read that it is a friend, so I assume it would be easy to arrange to go back with the correct test gear to get some factual results before asking on the internet? . At this point in time the test button is an irrelevant issue. Have you wired some of the installation or is it all done by another electrician? As you say it is only 7 years old, I am surprised the customer hasn't called back the original installer? I have move this thread to the student area.

Doc H