On the way home.

[Badfish]

On the way home I called into a customers house that they have only recently moved into. The fault in question was an rcd tripping on the left hand side of a dual split load board. I found out that the fault was a N-E fault on an old imperial cable socket circuit which needs the floor lifting to fix it. So with the agreement of the customer I isolated the circuit and will return to sort the fault. Any how, I decided to check the rcd but could not get my tester to trip on x1, fine on x 5.

Dodgy rcd I think so runs to the van and get a new one,fit it and same thing happens. This is a newish board and every thing looks ok, test button works fine. I also swapped rcd's from the other side and still the same. Has anybody had the same happen or shed any light on this. The board is a Hager.

thanks in advance.

 

[M107]

Did you test the rcd at the cu or from an accessory?

 

[Badfish]

Both still the same, tested other side from both as well and got results on x 1 and x 5.

 

[OnOff]

So you were testing with circuits disconnected from the load side?

 

[johninlondon1]

Time to get the tester out on the ciruits. Check if they have a timer to their heating, the fault could be when the heating comes on.

 

[Badfish]

Only the one circuit that was faulty was disconnected.

 

[M107]

Did the rcd when on the right side of the board trip ok?

So with all loads dissconnected & testing on the load side of rcd while it is on the left side of the cu, did it did not trip on x1?

 

[Badfish]

Right hand side rcd tested fine all loads disconnected left hand side all loads disconnected no trip x1 same when swapped over.

 

[OnOff]

By "loads disconnected" I'm guessing you mean with all the mcbs OFF? I wonder if it would make any difference with the load side neutrals and cpcs disconnected?

 

[NozSpark]

I was just about to suggest that maybe(?) the faulty circuit that you isolated still had it's neutrals connected?????

 

[M107]

Sounds like you've got a right one there & I can safely say it's not a fault I've had ..........................yet.

I am pobaly barking up the wrong tree...........but with a few bevvies now sunk.......... it has to be a problem on the supply side to the left hand rcd?

When you test the left side rcd is the right side of the cu also isolated?

I was assuming the isolation would mean you'd removed the load neutrals!

 

[OnOff]

I was just about to suggest that maybe(?) the faulty circuit that you isolated still had it's neutrals connected?????

Indeed, was thinking earth / neutral fault. Do your basic dead tests on that socket circuit for a start.

---------- Post Auto-Merged at 21:22 ---------- Previous post was made at 21:17 ----------

Sounds like you've got a right one there & I can safely say it's not a fault I've had ..........................yet.I am pobaly barking up the wrong tree...........but with a few bevvies now sunk.......... it has to be a problem on the supply side to the left hand rcd?

When you test the left side rcd is the right side of the cu also isolated?

I was assuming the isolation would mean you'd removed the load neutrals!

Was just thinking myself, should I be posting after beers and a curry!

 

[Steve3948]

Split Load board you say, is the front end time delayed, will not trip at 1X only 5X is normal on time delay.

 

[Badfish]

No time delay on the board I had disconnected the faulty circuit totally. Does appear to something wrong somewhere on the left hand side of the board just can't think what. Maybe further testing will make things clearer.

 

[Zeespark]

Badfish, in the words of KME - If you havent found the fault, you havent yet done enough testing.

AndyGuinness

 

[Badfish]

To be fair it was getting late and the customer was trying to get ready to go out. I will try to get to the bottom of this when I go back to fix the faulty circuit. Just trying to get a head start about what maybe wrong.

 

[OnOff]

Split load board......is there a link on the neutral bars still? Don't some boards come with the link in which you have to take out?

 

[Badfish]

No link I'm afraid the board all looks ok. Tis a strange one alright.

 

[springcrocus]

Whip the neutral tail out of the RCD neutral busbar, knock of all the MCB's and try again. If it reacts as is should, you're looking at the wrong circuit.

 

[steptoe]

By "loads disconnected" I'm guessing you mean with all the mcbs OFF? I wonder if it would make any difference with the load side neutrals and cpcs disconnected?

of course it will,

still obviously some people out there that dont understand disconnected mean Line & Neutral

this is basic stuff badfish, if you dont know to disconnect the outgoing circuits then you are out of your depth are not competent enough to be doing what you are doing.

the other thing, right hand side and left hand side mean absolutely nothing, you sound like a householder.

and people wonder why we are the laughed at trade workers ? (we are definitely not a profession anymore with people like that pretending to be sparks out there testing!)

---------- Post Auto-Merged at 22:51 ---------- Previous post was made at 22:49 ----------

To be fair it was getting late and the customer was trying to get ready to go out. I will try to get to the bottom of this when I go back to fix the faulty circuit. Just trying to get a head start about what maybe wrong.

best thing you could do is get a spark in