RCD trips every morning between 08.00 and 09.00

[telectrix]

the basic "harmonised" colours are brown for L, blue for N. black or grey can be used for either but must be sleeved with appropriate colours. so where for example you have blues for L, it's totally non-compliant with the stupid eu colour scheme.

here we've been perfectly happy with red for L and black for N till eu made us use the all colours are grey in the dark idiocy. than God we're out of the eu as soon as the politicians get their arses moving.

 

[pgrbff]

I’m often surprised by the huge difference in rules given the EU. You still get 240V light switches and sockets in bathrooms here, i was also told that the Italian regs insisted I have a TV aerial socket in every room or the electrician couldn’t sign off on the job.
I used to live on the “high street” of a small town, there was a butcher next door. Twice a week at around 5am, right below our bedroom on the 1st floor, a small lorry would back up and unload a live cow. I would then hear the chains running through pulleys as it was pulled up by its back legs.
For years In the UK farmers complained about the long distances their livestock had to travel for slaughter and the stress it caused, all because of EU rules. They don’t seem to apply here.

 

[marconi]

I can only see one perhaps two Green/Yellow conductors inside the annex CU. None visible in the main CU. Are final circuits provided with an earth (circuit protective conductor cpc) which is insulated GY?

Do you have an earth electrode close to the house and connected by a thick GY conductor to the Main Earth Terminal(MET) one in each CU?

Do you occasionally water (yes) the earth electrode? The plastic inspection cover should also have holes in it to allow rain water in.

 

[pgrbff]

Yes we have a new earth electrode, it has a lid which isn’t waterproof.
Immediately below each consumer there is a box through which all the cables are pulled. The brighter image is the box below the main consumer unit.
All the GY in the consumer units are tied together, main one too, and pass down to the boxes below.
I once stayed in a small house in Greece where every time you touched the shower knob you received that little fizzle! They insisted all we had to do was water the earth rod. We moved out.
We are not in a particularly dry area. We have never felt it necessary to water the rod. The earth rod is directly below the consumer unit one floor below.

 

[telectrix]

Yes we have a new earth electrode, it has a lid which isn’t waterproof.
Immediately below each consumer there is a box through which all the cables are pulled. The brighter image is the box below the main consumer unit.
All the GY in the consumer units are tied together, main one too, and pass down to the boxes below.
I once stayed in a small house in Greece where every time you touched the shower knob you received that little fizzle! They insisted all we had to do was water the earth rod. We moved out.
We are not in a particularly dry area. We have never felt it necessary to water the rod. The earth rod is directly below the consumer unit one floor below.View attachment 50702View attachment 50703

those pics are very appropriate for Italy. spaghetti nightmare,coloured as a meat feast pizza.

 

[pgrbff]

I installed all the sockets, working alongside the electricians, they all have earths as do all the light fittings. They did all the switches.

 

[pgrbff]

It is also a very expensive way to wire a house. On the upside it does allow you to modify the wiring.

 

[pgrbff]

It is also a very expensive way to wire a house. On the upside it does allow you to modify the wiring.

 

[pgrbff]

My electrician left me a voicemail today and I think the problem of the main CU is solved.
The two black switches on the left, main switch, and the RCD are combined.
If the main switch fires, it takes the RCD with it. I assume that the main switch might go for either a low or high voltage?
If on the other hand, the RCD detects a fault the main switch will remain on.
The problem with the voltage fluctuations will be a difficult one to solve, they say the lines to my house are the heaviest permissible.
So a restart seems to be the only option?

 

[pgrbff]

those pics are very appropriate for Italy. spaghetti nightmare,coloured as a meat feast pizza.

I thought you might like a look at some of the plumbing too.

 

[marconi]

The voicemail is not correct, or not totally correct. Let me explain.

The top left ENEL Arriva is where the main supply enters. It is a 32A circuit breaker which will trip on short circuit and prolonged overcurrent (as I described earlier). In its case, the 32A will hold for 1 hour at 1.13 x 32A and definitely trip after one hour on 1.45 x 32A. It is not sensitive to black out or brown out that is voltage because it is a passive device concerned with current effects(-but see later at # below). If it trips then you either have a short circuit fault happening or you are drawing too much current - see the hour figures I mentioned. The output of this circuit breaker supplies the RCD breaker (F202?) immediately to its right and the ds642p.

For clarity the ds642p is three in one unit as I explained in my first message, so this is all one device and the black switches will trip down on shprt circuit, overload or high earth leakage:



Did you do my test to discover if the RCD breakers (F202 and DS642P are active or passive types. If they are active then when the 32A ENEL breaker trips so will these two RCDS - so as the electrician said. But....if they are passive types then they should not trip if the ENEL breaker trips.

Now to # I mentioned above. If you have a short black out or brown out there may be such a brief surge in current upwards as the voltage returns or rises that the ENEL breaker is momentarily passing such a high current that it trips the short circuit mechanism - it is electromagentic functionality so fast acting (immediate) for currents from 3 to 5 times 32A or more (whereas the overload is thermal mechanic slow acting). If it trips it will need to be reset. If this is the case you may be able swap it for a less sensitive characteristic - we will discuss this once we know what kind of rcds you have.

 

[pgrbff]

The Enel Arrivo has never tripped to my knowledge.
The F202 to its right supplies the workshop downstairs which is physically disconnected from all machines and lights when it is not in use.
The single switch, Allogio, next supplies the granny flat.
It is only the ds642p and the elletrostop that all switch off together.

With all the mcbs to the right of the ds642p off, when I switch the Enel arrivo off the ds642p does not trip.

 

[marconi]

This indicates that the F202 and ds642p is a passive rcd devices - good.

The fact that the ENEL Arriva C32A does not trip indicates you have not drawn too much prolonged over current through it or had a short circuit - good.

You are back to checking background leakage current, ramp tests of RCDS wiring insulation resistances, testing individual equipments and appliances, connections, etcetera which have been mentioned by others. A competent, methodical electrician with the right test equipment, knowledge and experience and a bit of an Italian Sherlock Holmes in his nature.

Do your neighbours suffer like you or are you 'unusual'?

Had you thought about inviting out someone on the EF to take a look?

 

[marconi]

If I remember correctly some rural Italian single phase supplies do not have an earthed neutral which is why they mandate two pole circuit breakers. A single phase supply is derived from any pair of L1, L2 or L3. Do your electricity poles have three or four wires strung between them?

What you might ask ENEL is for them to move your home from the current two lines to another pair of lines to see if it makes any difference. You might just be connected to a heavily loaded line. You may have to swap again to try all the pairs of lines.

if it is three phase plus neutral (4 wire) you could still ask ENEL to move you to a lighter loaded phase.

Are you convinced you are not drawing more than 20A through the 642P 0800-0900 and in the run up to this period?

 

[pgrbff]

I don't have neighbours, we are at the end of the line. When they replaced the cables 2-3 years ago it was just for us. I'm not even sure if there is anyone else on this "spur". If there are it would only be small residential. I think we are fed directly from a substation and there are 3, I believe aluminium, twisted cables, possibly 80mm(2), but my memory has always been appalling so don't take my word for it.
It is hard to estimate but the line is probably around 2km long. It crosses a valley so is difficult to measure.
From what I understood there are 3 because I have the option of 3 phase and the non-earthed neutral does ring a bell.

 

[marconi]

I am going to let others follow up on whether you might be better off having a three phase supply and what would be required. It has great merit. Over a long distance lower currents in more conductors is beneficial to reduce volt drop and deliver the same power.

 

[marconi]

0800 to 0900.......

You have 2 fridges and a freezer. Are they frost-free?
To be frost free they have a heater controlled by a timer which is either a 24 hr clock with on/off settings or a stopwatch recording how long the compressor has run and after a predefined time turning on the heater.

 

[marconi]

Rather unusually, all your circuit breakers are Type C eg they are marked C20. In the UK, in the domestic setting they would normally be Type B and marked B20 for example. You might want to ask your electrician why this selection has been made and let us know what he says.

Here is an estimate of the volt drop for each amp of current flowing along the supply to your home where 0.33 V/A/km is the resistance per km at 25C of 85m2 aluminium conductor:

2 x 2km x 1 A x 0.33 V/A/km = 1.32 Volts

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So, when you draw say 10A the volt drop is 13V, 20A it is 26V, 30A it is 39V.

Thus if the supply line is energised at say 230V, the voltage at the end of the line will be 230 - 13 - 217V at 10A and 25C ambient. Volt drop will be more in higher ambient temperature.

Items with a motor draw some 5-10 times there normal running current when they start. Your Fluke may be reading very low readings because on the min/max setting the meter captures these brief but large dips in voltage as the motor runs up (on top of any other current being drawn).

 

[marconi]

Is there any socket you can plug temporarily the fridges and freezer in to which is not covered by the ds642P in order to see if the trip stops and moves to another rcd which trips?

 

[pgrbff]

The fridge freezer combo in the area that covers the tripping RCD is not frost free. It is a basic small fridge with freezer above. I do not think there are any sockets not covered by the ds642p that wouldn’t require a 50m extension. Surely there is no time function on such a fridge that would lead the RCD to trip more or less at the same time? Yesterday it did not trip, but the granny flat did. Today it ha not tripped. My feeling is that it is becoming more infrequent.
There are 3 elements that are timed in some way on the ds642p.
A small bronze pump circulating the hot water which comes on for 10 minutes at 06.30 and twice more during the day.
A gardena watering timer that when it operates causes a shallow well pump, less than a year old, to come on for 10 minutes around 06.30.
The solar pump which comes on when the panels reach a preset temp. Usually around 08.30. However I have been present on more tha one occasion when the pump came on without tripping the RCD and the RCD has tripped when there has been insufficient sun to cause the pump to turn on.