strange rcd problem

[cje512]

rewired property and fitted b g consumer unit , on testing rcd 1 tested fine , rcd 2 would nt operate on testing , test button is fine but on usual test procedure would nt operate , so exchanged it, but its exactly the same , however now on testing rcd 1 both rcd s trip out, i m baffled going back tomorrow, anyone help

 

[ackbarthestar]

It could be the way they are connected.
My first thoughts were that the tests were carried out on the supply side of the RCD, that would cause no operation then it maybe the two RCDs are wired in series and not in parallel. that would cause them to operate together.
I counted out the possibility of a borrowed neutral downstream, since it is a rewire....

 

[T&Earth]

Hi CJE

Are the C/U internal tails correct? how are you testing it? is the earth connected? perhaps ramp test if your merter has this option.

Not sure this will help
T&E

 

[cje512]

hi , have ramp tested it ,internal tails correct, its a baffler somethings gone on but can t figure it out yet .

 

[Strima]

Had a similar problem with a BG a few months ago. Ended up taking the whole lot out and refitting, RCD1 tails were incorrectly fitted which was glaringly obvious after quite a while of head scratching. Also a couple of the manufactured ferrules were loose. Not too happy with BG's quality control.

 

[ackbarthestar]

The problem with manufactured boards are that they are bundled around after leaving the factory, which means that components work their way loose.
I remember purchasing a new 12 way wylex 3036 box, a 'few' years ago now. The terminal screws were loose in the back of the busbar and it consequently blew one of the fuses and carrier straight out of the DB. The lesson was learned. I now check the components are secured before installing them

 

[GLENNSPARK]

well C/Us come with the advice to check the tightness of ALL terminations...including factory ones before commisioning......

 

[Strima]

It was the machine crimped ferrules that were loose. I have a nasty habit of checking all the screws for tightness as there are a few loose in my head...

 

[telectrix]

i would think that strima might have the answer. incorrect tails in CU. have fitted a few BG boards and had no problems, but there's always human error, no matter who makes a board. ( assuming there are no faults in the installation). try testing the RCDs at the CU with loads removed.

 

[Robinson]

Done it myself scratched my head for ages and didnt notice the buz bar was one piece hooked up continuous through both RCD's.
Dismantled it all took back to screwfix got another got back to find was doing the same.
At that point i realised after removing buzbar protection i had been a total dim wit and it was from factory like this. Just didnt look at the time and think buz bar would of been just stuck in as a whole.

ALWAYS GO THROUGH EVERY SINGLE CONNECTION IN BOARD ON COMPLETION FACTORY FIT OR NO FACTORY FIT. NICE AND TIGHT WE LIKE.

 

[Strima]

I can't be right, I'm never right...

 

[SPARTYKUS]

Strima, would love to see it! Love the conundrums.

 

[Knobhead]

It doesn’t only happen with domestic boards. I had a 12 way 60A Red Spot board delivered. When it arrived one corner had been damaged. If any of you know these boards you will know they are built like tanks. Anyway I had to install the board as it was. Once in that was the end of it as far as I was concerned, it was down to contractors to put the outgoing cables in.

After a couple of weeks colleagues were complaining of an awful smell in the switch room. I had a wander round and tracked it to my new board (me not happy now). It turned out the damage had skewed one of the busbars and the fuse bases. The bases weren’t making full contact with the fuse carriers.
There was a lot of finger pointing, I hadn’t wanted to fit it, the boss said it had to go in, why didn’t I check all the connections, who damaged it,,,,,, and on it went.

I’d never fit one again without checking. The upside, the company had to buy me a torque wrench.

View attachment 11579

 

[Guest111]

I can't be right, I'm never right...

you know what your problem is mate? your starting to believe everthing your wife tells you! lol

 

[Strima]

you know what your problem is mate? your starting to believe everthing your wife tells you! lol

You could be onto something there, from this day on I will never listen to my wife again...

I'll probably never be heard of again...