RCD tripping overnight with nothing connected

[leew85]

Good evening. Had a new consumer unit fitted a week ago, Paid over £500+vat for a proteus 5+5 board to replace an old non-rcd board. Ever since it was fitted the right hand RCD has tripped in the middle of the night, between around 11pm and 7am, every night. This powers a socket circuit, an oven, hob and an alarm. The oven and hob were isolated at the control switches and the ring had nothing plugged in. In order to attempt to figure out what was causing the tripping I switched off the oven, hob and ring MCBs, leaving just the alarm on, it still tripped. I then disconnected the 3 neutrals for those circuits from the neutral bar and taped them up, it still tripped. I then disconnected the alarm, leaving nothing connected to the load side of the RCD, it still tripped. So I called the guy to report my findings that I suspect the RCD is a dud, as cannot see why else it would trip with no load connected. He turned up, used an RCD tester to make sure that the RCD tripped within range, which it did, said the RCD was fine and left. Guy who fitted it claimed there was a borrowed neutral somewhere, but really struggling to understand how the hell that could cause an RCD with no connection to the load side to trip. Can anyone here explain to me how the hell an RCD with no load connection can trip overnight like this?
Thanks, Lee.

 

[SJD]

Just to check, the OP mentioned:
"I then disconnected the 3 neutrals for those circuits from the neutral bar and taped them up, it still tripped. I then disconnected the alarm, leaving nothing connected to the load side of the RCD, it still tripped."

I'm expecting to see 5x neutral cables at the right hand N bar, now all removed, is that correct? Or are there only four? Possibly one is hidden behind the bar & casing, and I'm not seeing it?

 

[leew85]

Just to check, the OP mentioned:
"I then disconnected the 3 neutrals for those circuits from the neutral bar and taped them up, it still tripped. I then disconnected the alarm, leaving nothing connected to the load side of the RCD, it still tripped."

I'm expecting to see 5x neutral cables at the right hand N bar, now all removed, is that correct? Or are there only four? Possibly one is hidden behind the bar & casing, and I'm not seeing it?

Yep there are 5 neutrals there (4 circuits, one of them a ring), all removed and ends taped with black insulating tape. Probs just can't see them all due to the camera angle.

 

[SparkySy]

the rcd neutral connection on the bottom right goes to the bottom of the main switch instead of the rcd so the neutral is not connected through the neutral side of the rcd!
Sy

 

[brianmoooore]

Y'know, I think he's right! My excuse is that I can't go to the optician's while my wife is shielding. What's the excuse for the rest of you?

 

[westward10]

the rcd neutral connection on the bottom right goes to the bottom of the main switch instead of the rcd so the neutral is not connected through the neutral side of the rcd!
Sy

Unless it is an hopital illusion you are spot on.

 

[nicebutdim]

I've looked at the image several times over the last hour and am pretty certain both neutrals leaving the main switch are feeding their respective RCDs.

Neutral link is definitely disconnected from load side of right hand RCD.

 

[loz2754]

the rcd neutral connection on the bottom right goes to the bottom of the main switch instead of the rcd so the neutral is not connected through the neutral side of the rcd!
Sy

I thought that but I'm not so sure. We need a picture from a lower angle to be sure.

 

[westward10]

If the conductors are formed like they are at the left side rcd then the right side neutral is missing at the rcd. The right side neutral links are all wrong.

 

[westward10]

@leew85 is there a blue connected from the bottom of the right side rcd.

 

[streamer]

Re-read some previous posts and changed my mind!

 

[leew85]

The factory neutrals all seem ok:
Bottom of main switch to top of left RCD
Bottom of left RCD to left neutral bar
Bottom of main switch to top of right RCD
Bottom of right RCD to right neutral bar

 

[SparkySy]

It looks from your photo that the neutral link to the terminals is in the bottom of the main switch, and there is no neutral link in the bottom of the rcd.

 

[SparkySy]

And I agree those tails have way to much copper showing!

 

[Grant1987]

And I agree those tails have way to much copper showing!

That consumer unit is awful, as soon as you take the cover off and see the mess like that alarm bells start ringing. I understand when cables are short and need to be crimped doesn’t help the matter but that is shocking no effort whatsoever on there

 

[Grant1987]

That consumer unit is awful, as soon as you take the cover off and see the mess like that alarm bells start ringing. I understand when cables are short and need to be crimped doesn’t help the matter but that is shocking no effort whatsoever on there

Wait there I’ve just looked back they are all new colours and has plenty of cable length to terminate just makes it even worse. Wow that is dog rough.