RCD trips every morning between 08.00 and 09.00

[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).