RCD trips every morning between 08.00 and 09.00

[marconi]

No a timer is for a frost-free fridge or freezer.

It may not be when equipments turn on that causes the trip but when they turn off. You might want to check the off times for the things you just mentioned.

Is your hob or oven electric? it is a common problem for the electric elements to have earth leakage which can cause rcds to trip. The ds642p supplies your cucina. Might you turn the hob and oven off at its isolator switch when you aren't using them to see if the 0800-0900 aspect of the problem 'goes away'. (I don't want to explain the electrical reasoning just now 'cos I have not the time).

I still think it a good idea (ie. I would do it if I was you) to invite soon an electrician to do the testing and inspection I and others have mentioned because it would rapidly establish the state of your wiring installation and loads connected to it. It also has value in both quality and safety assurance for your peace of mind and your insurers. The Brains Trust which is the EF need some hard information in the form of electrical measurements to consider your problem further. Money well spent. That's my professional opinion - gratis.

I am going out now 1000 UK and will look again after lunch.

 

[pgrbff]

There is no hob or oven beyond the ds642p yet. We currently live in the granny flat. Almost all of the sockets beyond the ds642p are vacant. Bo the timers, watering and water circulation are only on for 10 minutes. Once the solar pump starts it will run all day, but the ds642p has never tripped in the afternoon-evening when the pump would stop.
Given all the problems I have had over the years with the supply, I still can't help think it is the problem.
I am waiting for the electrician to call me. Amongst other things, I'll ask him if he can do some testing.
Can you tell me again what tests@ I'll have to try and work out the translations.

 

[marconi]

I too think you have a poor supply. But first you need to clear your installation of any faults if they exist before remonstrating with ENEL. You may have both installation and supply problems.

DPG - would you advise pgrbff please on I & T, as I see you have been reading the posts. Or someone equally good?

 

[Wilko]

Hi - I know I’m late to the party, so apologies if this has already been covered
1. What type of earthing do you have?
2. Tell us about this solar pump thing you mentioned in the first post. Do you have solar panels? An invertor? Is it attached to your Consumer Unit? If so, I’d disconnect it all and see what happens tomorrow morning .

 

[marconi]

pgrbff: I have more time now and I don't think DPG has seen my post to him.

If you look at Mattg4321 #14 he has listed the important tests and the order in which to do them - the key words to translate are in bold. I will see if I can find some youtube clips you might look at too:

1. Insulation resistance of wiring between L and N, L and E and N and E at 250V and then 500V

2. Ramp testing of the RCDs.

3. With ENEL ARRIVA closed, total earth leakage current measurement using a clamp meter around the incomers and then around the earth conductor to the earth electrode.

and I would add a fourth and fifth

4. Check all connections are tight in consumer unit and kWh meter and do a 'tug' test on all ferrules to check conductors are indeed gripped inside them.

5. Check insulation resistance of appliances both portable and fixed which are normally energised on the circuits protected by the RCDs.

 

[marconi]

electrical wiring - cavi elettrici

electrical testing equipment - apparecchiature per prove elettriche

test di resistenza all'isolamento

250 Volts - 250 Volt

500 Volts - 500 Volt

test di rampa di interruttori differenziali

corrente di dispersione verso terra totale

incomers - cavi di alimentazione principale

earth electrode current - corrente dell'elettrodo di terra

tightness of connections - tenuta delle connessioni

pull test on ferrules - tirare il test sulle ferrule.

 

[marconi]

50m extension cable:

Cavo avvolgitore cavo protonics 50 m Cavo prolunga con dispenser V 111: Amazon.it: Amazon.it

Compra Cavo avvolgitore cavo protonics 50 m Cavo prolunga con dispenser V 111 a prezzi vantaggiosi su Amazon.it. ✓ Spedizione Gratuita disponibile per membri Prime su oltre un milione di prodotti.

www.amazon.it

 

[marconi]

I have asked an eminent electrician of the Electricians' Forum how much he reckoned these tests would cost and how long to do them. For a typical 3 bed house no more than £100 and a couple of hours at most with the right test equipment and competency in its use - this does not include searching for any faults, just the testing.

 

[pgrbff]

Many thanks for all your help. Much more than I would have expected. It has now been 3 days since the last time the RCD tripped, something has changed.

 

[marconi]

I don't want to overly alarm you but could you have a problem with rodents eating cables under the floor or in the loft or in outbuildings? Or ants getting into connections and electrical enclosures?

Have you had a period of wet weather followed by hot weather which has dried out everything?

Could you walk the length of the 2km line and check the conductors are in free space and not bothered by trees, etcetera. Or that no-one is pinching electricity by clamping on to the cables directly.



Please keep us posted.

 

[pgrbff]

I can see most of the lines from the house, and they’re insulated.
We have lots of ghiri, Roman doormice, in the roof space, they keep you awake at night running up and down or eating the roof insulation. 99% of the wiring is not accessible to rodents, can’t say the same for ants.
We had a much, much drier year two years ago. So dry that we had new cracks appear as the 100/200 year old building settled a bit. The buildings are stone with only mud between the stones, no mortar.

 

[pgrbff]

Hi - I know I’m late to the party, so apologies if this has already been covered
1. What type of earthing do you have?
2. Tell us about this solar pump thing you mentioned in the first post. Do you have solar panels? An invertor? Is it attached to your Consumer Unit? If so, I’d disconnect it all and see what happens tomorrow morning .

Earth is a copper plated steel rod approximately 1,5m deep
The solar pump circulates water from solar panels on the roof for indirect hot water. No photovoltaics, too expensive here.

 

[Wilko]

Earth is a copper plated steel rod approximately 1,5m deep
The solar pump circulates water from solar panels on the roof for indirect hot water. No photovoltaics, too expensive here.

Hi - just a simple thing, but perhaps have a close look at the rod and the cable linking back to your board. Check cable is continuous and the connections at each end are sound and corrosion free.

 

[HappyHippyDad]

Like Marconi says it would be best to get an electrician out to do all the required tests. However, if you intend to fault find yourself then i would slowly, over time eliminate all appliances one by one.

If the tripping is everyday between 8-9 then that is perfect as the tripping is consistent rather than random. You can just unplug/switch off one item and see if it still trips the following day. It would need to be a controlled experiment though. Just unplugging something and seeing if it fails to trip the following day would not be enough. I would then plug it back in and see if it then trips the following day. This would add to the degree of certainty.

Even if the above does not work it has still eliminated some possible causes and you can then focus elsewhere. i.e the supply, faulty RCD's etc etc.

Hopefully your tripping problem has gone away (as you have said), but I have had a few customers who cancel on me because it stops tripping. Only to get a phone call the next day apologising and asking me back as it has started again.

Also, It would be worth spending the money to get it properly checked even now, as if it has been tripping that often then something was clearly very wrong and may still be there even though it's not tripping now.

 

[pgrbff]

Still waiting for the electrician, his son and father are both in hospital and I am not that close to where he lives.
After a month of problems with the mainboard tripping virtually every day at more or less the same hour, it has now been over a week since the RCD tripped. The annexe board, however, has started tripping again, only three times in 8 days, all in the morning, but I'm not sure we are ever going to get to the bottom of this.

 

[static zap]

but I'm not sure we are ever going to get to the bottom of this.

--if you keep a calendar ,add weather ,temp ,rainy days ...
May have some clues.
(and clues -when to call again next year)
...If you move any equipment about ..
add dates if (just in case any patterns change)

a) Others hammering the fans/air-con
b) Water seeping in somewhere & drying out.
c) Overnight condensation-re distributing.
----There is a chance damage is being done -and will eventually become a Permanent thing---

 

[pgrbff]

I have kept a diary and unfortunately, over the last 3 /4 years it has been fairly random. We have periods where the RCD regularly trips, and then it stops for a while and the pattern changes.
Some trips are expected, we had storms the last few days and the RCD in the annexe switches off, and when it snows in winter.
The voltage varies all day and we have regular blackouts.

 

[marconi]

Would you consider spending money on a battery and inverter which would power your home and annexe? The mains supply would be used to charge the battery. When the supply is of the correct voltage the inverter could be set up to go into 'bypass mode' connecting the supply to the loads avoiding discharging the battery; otherwise when the input voltage is out of specification the inverter automatically switches to the battery with no loss of output voltage. You could also buy an inverter which would take an input from solar panels.

Here are some prices for different sized(kVA/kW) inverters:

12V solar panels charging kits for caravans, motorhomes, boats, yachts, marine

12V solar panel solar charging kits for motorhome caravan boat campervan yacht marine off-grid

www.photonicuniverse.com

You would also need some batteries - good ones which I can talk about if you are interested.

 

[pgrbff]

I have considered using solar but the incentives here aren't very good anymore.
I really need to formally complain to Enel again, my electrician keeps telling me to do so, but they have already replaced two/three km of lines to my home with what they say are the heaviest permissible. I'm not convinced that it is simply a case of being too far from the substation but basically, I would have to pay for monitoring and dealing with the bureaucracy here is nothing short of a nightmare.
I have to go away for a few days now and will have to ask my nearest neighbours, an elderly couple, to drive up at least once a day to check nothing has tripped. This is worse than it seems because the road is in a terrible state, missing tarmac in may places.

 

[pgrbff]

I

Would you consider spending money on a battery and inverter which would power your home and annexe? The mains supply would be used to charge the battery. When the supply is of the correct voltage the inverter could be set up to go into 'bypass mode' connecting the supply to the loads avoiding discharging the battery; otherwise when the input voltage is out of specification the inverter automatically switches to the battery with no loss of output voltage. You could also buy an inverter which would take an input from solar panels.

Here are some prices for different sized(kVA/kW) inverters:

12V solar panels charging kits for caravans, motorhomes, boats, yachts, marine

12V solar panel solar charging kits for motorhome caravan boat campervan yacht marine off-grid

www.photonicuniverse.com

You would also need some batteries - good ones which I can talk about if you are interested.

I would like to use at least some solar but the way it works in Italy, as I have understood it, is that a company looks at your usage, installs panels that should cover that usage for free, then you continue to pay your electricity company more or less what you were paying before to rent the panels.
I have friends that have bought their own panels, costing between €4500 and €20,000 and none of them have had any payback from their electricity companies. They even pay a monthly charge to rent the new solar electricity meter.
I have always thought that batteries would prove too expensive. I use lipos in my hobby, flying radio control helicopters, and apart from the cost they don’t seem to have that many charge cycles.
If I could incorporate a battery system that might actually save me some money over time I would certainly consider it.

 

[Bobster]

Powerwall | Tesla

Powerwall is a home battery designed to store energy from solar or the grid, so you can use it anytime you want—at night or during an outage.

www.tesla.com

Maybe this would be something to look into?

No personal experience with the product, but in principle should work well for you.

Clearly cost/payback analysis would need to be done, an I'm sure other manufacturers make similar solutions.

There maybe members that have installed or have first hand knowledge with these systems.

-

Regarding your RCD issue, a good electrician should be able to rule out your fixed wiring pretty quickly against it being a problem.

Once this has been ruled out, an auto re closing RCD maybe the most cost effective solution, if the issue is with your provider.

 

[marconi]

Could you list the equipment which is permanently plugged-in and ready for use, including items such as the washing machine even if the on/off switch or programmer is set to off? Do you have any interference filter socket strips or surge suppression socket strips plugged in. IT equipment?

 

[marconi]

Could you measure the voltages L-N, L-E and N-E at the input to the Arriva ENEL Disconnector (top left) when the Disconnector is open and then immediately afterwards closed? It would be helpful if you could do this on a number of occasions over a few days.

 

[HappyHippyDad]

I would just pay for Marconi to fly out to you. Cook him some nice meals and splash out on a fancy bottle of wine and your problem will be solved!

 

[pgrbff]

Could you measure the voltages L-N, L-E and N-E at the input to the Arriva ENEL Disconnector (top left) when the Disconnector is open and then immediately afterwards closed? It would be helpful if you could do this on a number of occasions over a few days.

I'm off to Venice tomorrow morning, my dad is having his hip replaced and he is 85, mum has dementia so not sure exactly when I'll be back. That is why I was looking at the restart RCBO. One of the RCDs is bound to trip whilst I'm away. I will definitely do when I'm back.

 

[marconi]

Happyhippydad - no pressure then!

One of the things I am thinking is happening is that the supply is IT ie: the N is not earthed anywhere so effectively the supply is L1 and L2 both at a phase voltage wrt to 'earth'.

Stray capacitive effects will be at play causing earth leakage currents, often much higher when there are dramatic voltage variations as he experiences.

You know that for TN and TT it is wise to ensure the deltaIn is 30% of the design deltaIn because for a steady 50% of design deltaIn (ie 15mA for 30mA RCD) it will operate and open.

This limit is much lower for an IT system for reasons I will not go into now. The wise maximum leakage current to minimise nuisance trips through capacitive currents is 17% of deltaIn so 0.17 x 30 = 5.1mA! - so you can see the RCD may be on the edge.

HHD - so why did I suggest the voltage measurements in my recent message?

 

[pgrbff]

Powerwall | Tesla

Powerwall is a home battery designed to store energy from solar or the grid, so you can use it anytime you want—at night or during an outage.

www.tesla.com

Maybe this would be something to look into?

No personal experience with the product, but in principle should work well for you.

Clearly cost/payback analysis would need to be done, an I'm sure other manufacturers make similar solutions.

There maybe members that have installed or have first hand knowledge with these systems.

-

Regarding your RCD issue, a good electrician should be able to rule out your fixed wiring pretty quickly against it being a problem.

Once this has been ruled out, an auto re closing RCD maybe the most cost effective solution, if the issue is with your provider.

I'd heard about the reliability of Tesla, but also the cost. Not sure if I'd get my money back, even over 10 years. Nice idea, I'm afraid I can't afford it.
I have ordered two restart RCBO's, not because I can't be bothered to find the cause, but after 3 or more years I need to know I can go away for a couple of days without worrying too much.

 

[pgrbff]

Happyhippydad - no pressure then!

One of the things I am thinking is happening is that the supply is IT ie: the N is not earthed anywhere so effectively the supply is L1 and L2 both at a phase voltage wrt to 'earth'.

Stray capacitive effects will be at play causing earth leakage currents, often much higher when there are dramatic voltage variations as he experiences.

You know that for TN and TT it is wise to ensure the deltaIn is 30% of the design deltaIn because for a steady 50% of design deltaIn (ie 15mA for 30mA RCD) it will operate and open.

This limit is much lower for an IT system for reasons I will not go into now. The wise maximum leakage current to minimise nuisance trips through capacitive currents is 17% of deltaIn so 0.17 x 30 = 5.1mA! - so you can see the RCD may be on the edge.

Didn't understand any of that. But I think you are sort of confirming, without me convincing my helpful and professional, but very Italian electrician, to undergo all the testing, that it is probably a supply problem.
I have very little knowledge, I'm far from academic, but I do think I have more than my fair share of common sense. The utter random nature of what has been happening has 99% convinced me already that this is not something in the house.

 

[pgrbff]

In a couple of days it will be August, and in August everything shuts down in Italy.

 

[Bobster]

Didn't understand any of that. But I think you are sort of confirming, without me convincing my helpful and professional, but very Italian electrician, to undergo all the testing, that it is probably a supply problem.
I have very little knowledge, I'm far from academic, but I do think I have more than my fair share of common sense. The utter random nature of what has been happening has 99% convinced me already that this is not something in the house.

The good thing is though (or unfortunate for you currently) is that it isn't entirely random as you state, but at a fairly specific time of day.

If you cover my costs to Italy, I'll happily get to the bottom of it for you.

On a serious note, an electrician with some test gear should prove your fixed wiring and most appliances that are permanently powered in a couple of hours.

You want them to be testing at a minimum, the insulation values of effected circuits, cumulative earth leakage, RCD tests including ramping the RCD and then to PAT test the appliances. (It's not called PAT testing anymore, but everyone knows this terminology, unsure of the equivalent name in Italy).

 

[marconi]

I think you have two problems:

1. The nuisance RCD tripping;

2. A supply problem by which I mean everything owned by ENEL up to the input terminals of the ENEL Arriva disconnector.

For (1) I believe there is an interaction between the supply problem and the electrical characteristics of your wiring and the loads connected which is causing transient 'differential currents' of sufficient size to trip the RCD. I think these transient differential currents are more significant because you have an unearthed mains supply unlike say in the UK where the neutral is connected to earth. I reckon you also have a 'weak' earth which means that electrical noise can be introduced into the wiring and loads via the green/yellow earth conductor. It is is starkly apparent when there is a trip because all your circuits are protected by one RCD per dwelling - bad practice. In my home the circuits are spread over 4 RCDS and one RCBO. The cheapest minimum is two RCDs per dwelling. There are also RCDs which are less sensitive to transient effects which cause nuisance tripping and which have a higher standing threshold current at which they trip (between 0.7 and 1 x deltaIn).

For (2) I believe there may be a joint fault, an insulation fault, or someone also connected on occasion drawing a large current and consequent volt drop. It is also a tall order for such a long feed to supply up to 5kW to your home when the energising voltage at the transformer end is circa 230V - Ohms law and volt drop effect. There is also the significant transient surge in current when motors start say in your fridge or water pump which will cause a brief but noticeable volt drop.

Last, the wiring technique of running many conductors together in conduit around the house increases capacitive linkage between them and the possibility of induced currents ; some of which might cause earth leakage currents or differential currents detected by the RCD. Any filters commonly found in white goods, computers, also 'dump' transient and steady currents to earth which the RCD 'sees' as a differential current. The threshold for nuisance effects is lower for an I-T earthing system which I reckon you have.

What you can buy are RCDs which are less sensitive to noise and disturbances - but I think the best solution is to spread your final circuits over a number of RCDs or even better an RCBo for each final circuit. If you did the latter it becomes very obvious which circuit or load is the offender in the event of a fault or nuisance trip and the whole house is not blacked out.

Even new wiring in good condition can have minor faults which can over time cause trouble - hence on completion and then regular inspection and testing.

You either make your installation more resilient to electrical disturbances or you isolate it from the mains supply using the battery, charger, inverter idea for which the mains supply then simply charges the battery and the battery powers the site through the inverter.

Or, (3) you opt for a three phase supply or (4) ENEL install a high voltage line to your home and only then transform down to 230V. With (4) you could have a decent local earth which enables also a neutral.

 

[marconi]

Pgrbff - hello again. I wondered if your trip problem had been fixed?

 

[pgrbff]

I bought the two restart RCBOs but August is only just over, and a month when Italy shutsdown completely. I am away still looking after my elderly parents. I leave a light on at home and an elderly couple some 3km away check every night to see if I still have power. Neither board has tripped for over a month, but this is not unusual, the problem is completely randomn and could return at any time. This is why I am convinced that it is with the supply rather than home. My electrician only returned to work at the end of August and I will ask him to fit the two restart RCBOs. He has always said I should complain to Enel who look after the supply and I probably will when I return home. Thank you for your interest, I wish I could tell you more.

 

[marconi]

Va bene.
Sai come contattarmi.