please help !!! RCD Poblem

[cyberjunction]

Hi

I am doing my first consumer unit for my assesment on Friday and have come a cropper.

I have put in a split dual consumer unit, Wylex.

On the one half, closest to the main switch, the rcd works fine.
The second RCD, the test button does not work . When I apply a load ie upstairs kights , it trips straight away.Obviously thought the RCD was faulty so took it back and got it replaced and the same problem. I have disconnected all lines form the MCB and the buzz bar but the same problem. I have ensured there is no connection between the neutrals on the neutral bars as some one suggested and am completely stuck,

Can anyone help, I am panicking with my assesment due and am hoping this is something silly.

Just a note there is voltage to the RCD.

the preivous consumer unit was a single rcd and MCDs with problems

Thanks

 

[cyberjunction]

double checked all wires to the rcd - everything "looks right" will try all suggestions and update in the morning thanks all

 

[RWJ]

Where about's are you cyber maybe one of the forum could pop round with you and take alook

 

[cyberjunction]

west mids post code b98
would happily supply beer to anyone who could

 

[RWJ]

Too far for me buddy.... Sorry

 

[tony mc]

You say once the load of upstairs lights goes on it trips the lights so the RCD is stable until you switch the lights.

Sounds like a borrowed neutral.

Try putting all lights on the same mcb!!

 

[cyberjunction]

no worries - cheers though!

 

[cyberjunction]

bit more of an update i have turned on 100w worths of light upstairs and it is not tripping the switch, if I connect the ring and/or the immersion heater it will trip. the test button still does not work though

 

[cyberjunction]

rcd just tripped - the lights been on for about a minute before tripping !!

 

[cyberjunction]

going to leave it now and have a fresh head in the morning
thanks all

 

[tony mc]

You need to dead test the ccts Im affraid as its just a guessing game .

Carry out all of your tests from scratch and connect all your sockets and switches before IR testing so you know that you have not nipped a cable etc when tighting them up.

When your head is clear go through you test sequence step by step taking your time and you will come across the fault.

Good luck and let us know how it goes.

 

[lloyd1980]

are any of the neuterals mixed up?
and I know it sounds noddy but you have cut the busbar in half at the bottom havnt you?
not sure about wylex but a lot of duel boards the busbar is in 1 solid peice and you need to cut it otherwise mad faults everywhere on energising

 

[tony mc]

Wylex comes in two pieces

 

[Smugley]

Wylex always have two or three separate busbars.

edit: snap!!

 

[gtownspark]

If the new fuseboard & RCD's are wired correctly then the best bet is to turn off all the MCB's off, then reset the RCD and switch the MCB's on one at a time until you find the circuit that is causing the RCD to trip.

 

[Deleted member 9648]

You need to sort out why the test button doesnt work first,the RCD cant be wired in correctly which may or may not contribute to the tripping...once you are positive that is operating correctly go from there with any tripping issues.