Main 'fuse' (RCD) tripping

[barki]

Before this topic progresses any further, do you have an overhead mains supply feeding into your house?

Yes I do. How did you know?

 

[Jurassicspark]

What is the earthing arrangement?

Is it possible that someone else, knowingly, has turned off the main RCCB, and there is no fault present?

 

[barki]

Photos here

Garage setup - Incoming supply, meter, big switch and small consumer unit for garage circuits (which includes a small utility area).

 

[Scally-Ho]

I know because overhead supplies used to be 'earthed' via a voltage sensitive tripping device. That more modern version main trip is obviously a replacement relying on current leakage.

 

[barki]

What is the earthing arrangement?

Is it possible that someone else, knowingly, has turned off the main RCCB, and there is no fault present?

Zero chance of anyone else touching it. No one else has been here, kids are too young to reach that far up, the dog likewise and the wife absolutely wouldn't touch it with a barge pole.

 

[Scally-Ho]

What is puzzling me the main breaker is 100ma, but the CU with 2 far more sensitive RCD's are not tripping. Something not right there.

 

[Scally-Ho]

Ah-ha! One of the CU's RCD's is rated at 100ma, so that one is probably not quite as sensitive as the main one. The problem most probably lies within the section served by that 63a 100ma RCD

 

[barki]

Lovely, thanks, that does narrow it down a lot, not much on those two!

 

[AndyPRK]

The main one is time delayed.

 

[AndyPRK]

That light circuit next to the 100mA.
Any outside lights on it? Any water in them ?

 

[AndyPRK]

Turn off that B40.

See what doesn’t work. And if it’s not important, see if the trips stop too

 

[ericmark]

I am now confused, two different consumer units, and a 100 mA RCD fed from a 100 mA RCD, so previous comments clearly wrong.

As already said, the type S 100 mA RCD was used to replace the ELCB-v which in turn was used because water mains and gas mains which had been used for years as an earth electrode were replaced with plastic, so the whole idea was reversed and the water and gas had to be earthed by the homes earth electrode.

I found with my parent's house, often the earth electrode is often missing.

So I expect much of what has been said, by me, will have gone over your head.

Anyway, it is possible one fault would not cause a problem, but two faults can cause a trip, and I am considering what is your best option, but to start with want it ensure your house does have an earth. Looking for an earth pit

it should have a cover, but not always,

sometimes there is just a simple rod. I look at the pictures and see this earth wire, ⁣but

see nothing connected to the DNO head or consumer unit.

 

[Murdochcat]

I think you need to locate a local competent spark.

Get them to test ALL the RCDs to see if they are operating within expected parameters

In the mean time maybe keep a record of when it trips

 

[ericmark]

In theory the low mA should trip before high mA and non-delayed before delayed (S), but in real life I have seen 30 mA, 100 mA, 300 mA and 1 amp RCD's all trip together when a guy put a nail through a cable to hang his coat on.

I think you need to locate a local competent spark.

I will second that, as I think possible there is a missing earth rod.

 

[barki]

Many thanks again for looking at this.

It seems I do have an earth rod (bottom right of these pictures). Hadn't paid any attention to it before.

This is located behind the garage by the oil tank. I can travel the cables back to the main earth lead identifed next to the meter (that EricMarc above took them snippet photo of), but it goes in generally the right direction before disappearing into the flooring.

Would you expect just one of these (and not another near the boiler - in which case I've not located a 'main' one)?