Consumer unit trips without reason that I can find

[teddysnips]

[...]

I've looked and failed to find a make for the CU. All I can find is a logo, which looks like a box containing an ellipse containing a triangle pointing to the right: ____ [ ( |>) ]

Best picture I could muster here:

've looked on the web for an example of a Chint logo but couldn't find one.

I've tried turning off the dishwasher (an early candidate) - it has a switch on the wall in place of a plug but there was another trip so I presume that I can rule out the dishwasher?

The overall box is a single moulded piece of plastic, and the items inside are modular. I could take the cover off (possibly) and take more pictures, but I don't have any confidence in staying alive during this proceeding.

Better pictures of the top row of switches here:

the bottom row again.

's also this box thing attached to the top of the unit. I think it's something to do with the doorbell.

- any further thoughts?

Edward

[Jim Alexander]

[...]

I've looked and failed to find a make for the CU. All I can find is a logo, which looks like a box containing an ellipse containing a triangle pointing to the right: ____ [ ( |>) ]

Best picture I could muster here:

've looked on the web for an example of a Chint logo but couldn't find one.

I've tried turning off the dishwasher (an early candidate) - it has a switch on the wall in place of a plug but there was another trip so I presume that I can rule out the dishwasher?

The overall box is a single moulded piece of plastic, and the items inside are modular. I could take the cover off (possibly) and take more pictures, but I don't have any confidence in staying alive during this proceeding.

Better pictures of the top row of switches here:

the bottom row again.

's also this box thing attached to the top of the unit. I think it's something to do with the doorbell.

- any further thoughts?

Google "DZ47" and you will learn something to your advantage.

But to get back to your problem, I don't think the make is as important as the system design issues alluded to by several people here but which you don't yet seem to have acknowledged.

Jim A

[teddysnips]

[...]

I didn't. What exactly do you think I might learn that would be to my advantage?

It's not that I haven't acknowledged it, it's just that I haven't the faintest idea what they're talking about! Seriously, electrics is a Black Art as far as I'm concerned. I originally posted hoping someone would give me a few steps that I could take to locate the problem. As the thread has gone on, it's become increasingly clear that there may be any number of possible solutions, almost none of which I am personally competent to pursue.

Edward

[Appin]

The message

from [e-mail] contains these words:

I think there's general agreement that your consumer unit has been wired in a less-than-dieal way.

It's possible to change the way it's wired in order to minimise the possiblity of nuisance trips and limit the damage they can cause.

Although your box does not appear to be a current-production Chint, everything about it seems to indicate Chinese -- though that's not a negative thing at all.

Since you don't have the expertise to put into practice the suggestions re your consumer unit, you're going to have to call in an electrician to make sure that the cooker, hob nad water heater are no longer on an RCD and that the 30mA RCD is changed for a 100mA RCD. That las change alone might remove the nuisance tripping.

[John Rumm]

To be fair, most of anything we could cover here is spelt out in detail in the nuisance trip section of the wiki on RCDs.

specifically:

wrote this article because the problem you have does come up from time to time, and tracing and rectifying it can be difficult.

Perhaps a more workable way forward is for you to read through the article and come back with specific questions that it raises, or highlight any bits that you don't understand. That way we can either explain or improve the descriptions in the wiki.

Part of the difficulty here is that the problem you are trying to solve may be caused by something quite subtle and the cause of it may be complex to understand especially without some background knowledge. Once you have run through the empirical tests in the fault finding section you get into the more difficult tests that involve opening your consumer unit and using test equipment. If you do not feel that you can do this safely then it is time to hand over to someone else. However if you can start by eliminating a number of likely causes you will make the task easier for them (and cheaper for you)

[John Rumm]

Since the 30mA RCD is the only one, and it offers protection to the sockets you can't replace it with a 100mA one since this does not provide the required shock protection.