RCD Earth Leakage

[garysparky1]

I Need a little help i recently fitted a new consumer unit for a mate. The house is empty and up for sale so i thought no problem as not in a hurry continuity was ok on all circuits IR ok ,Ze 0.09,PFC 2.95kA so i changed the board then powered up and the 80a 30Ma RCD tripped i disconnected each circuit and reset it tripped on each circuit. I've since gone back with a clamp meter and found 29-39Ma running through the bonding. I clamped ( on lowest setting)the neutral and line seperately on each circuit and got kitchen N-0.70 L-0.46Ma and downstairs lights N-0.47 L 0.10 surely these differences in reads are too high can anybody steer me in the right direction. :frown2:

 

[Top Cat]

If you say it tripped out on each circuit (mcb) then it looks like a neutral fault.

Disconnect all neutrals and do IR again. If it is a 17th edition board with 2 RCD's make sure you have not got neutrals crossed between RCD's. Finally check if upstairs lighting has a "borrowed" neutral ie. The landing light has not got its neutral from downstairs lighting circuit.

 

[plugsandsparks]

Are these readings with loads on the ccts. Is polarity correct ? You mentioned just one rcd, is there another one ?

 

[Top Cat]

If you say it tripped out on each circuit (mcb) then it looks like a neutral fault.

Disconnect all neutrals and do IR again. If it is a 17th edition board with 2 RCD's make sure you have not got neutrals crossed between RCD's. Finally check if upstairs lighting has a "borrowed" neutral ie. The landing light has not got its neutral from downstairs lighting circuit.

Correction meant to say upstairs!

 

[garysparky1]

it's an 8 way BG board with only one 80a 30Ma RCD the readings are taken from clamping each circuits line and neutral as the RCD keeps tripping MCBs are fine what do you make of the 29-39 Ma current going through the bonding ?

 

[Top Cat]

it's an 8 way BG board with only one 80a 30Ma RCD the readings are taken from clamping each circuits line and neutral as the RCD keeps tripping MCBs are fine what do you make of the 29-39 Ma current going through the bonding ?

So it's not a 17th edition board, i think you only have a clip on Amp meter, are you an electrician?

 

[garysparky1]

hmm its a British General 17th edition Board a digitron clamp meter and im 17th edition mr cat

 

[Top Cat]

hmm its a British General 17th edition Board a digitron clamp meter and im 17th edition mr cat

I don't see how it is 17th edition with only 1 RCD.

Yes you have a clamp meter, good for you. You have not said whether it is your only meter.

Do you have an IR meter.

You did not answer whether you are an electrician or not.

Thank you Mr Gary

 

[Plonker 3]

Did you carry out a EICR before changing the DB?

Have you checked for a shared neutral?

 

[WPD Lad]

Sounds like a 16th edition board