RCD trips every morning between 08.00 and 09.00

[pgrbff]

I live in rural Italy. You get to chose your max KW here and pay accordingly. Most home have 1.5-3.0 kw, I pay extra for 5kw. I am at the end of the low voltage lines, one of only a few on this circuit. I constantly have voltage problems, according to my fluke multimeter it can go from 190v to 234v over a few minutes without me changing the loads at home. Every time you switch something on you can here it from either the bathroom fan, cooker fan or oven fan slowing down or speeding up.
My main problem is that the RCD often trips, picture attached. Currently it is tripping nearly every morning between 8am and 9am. There are currently no devices on time clocks. I thought it might be the solar pump coming on but it isn’t. It trips when there is no sun and the pump is off.
I was considering installing a “restart” RCD but would be interested to know what you think. My electrician, although quite good does little more than shrug his shoulders.

 

[Lister1987]

Central heating? Time clock firing immersion on? Thermostat firing immersion on temperature drop?

 

[pgrbff]

The 3 central switches all go together.

Central heating? Time clock firing immersion on? Thermostat firing immersion on temperature drop?

Central heating? Time clock firing immersion on? Thermostat firing immersion on temperature drop?

No central heating or hot water other than solar. Solar not on clock. Pump kicks in when panels hot enough. Have stood and watched temp go up and pumps kick in without causing rcd to trip. Rcd has also tripped on days when too cloudy for solar pump to fire.
No immersion, gas boiler also off as not needed. Time is also not always exactly the same, just between 8am and 9am, never at any other time of day

 

[DPG]

Do any of your neighbours have something that switches on at these times?

 

[pgrbff]

I'm not even sure if there are any other properties on these lines, but it is perfectly possible. I assume a restart RCD would solve the problem? How do I determine if it is 2 or 4 pole?
The unit on the right is an RCD, what is the two gang switch on the left? Justa an MCB?
The wiring here is very different to the UK.

 

[static zap]

Thoughts try narrowing it down to the 3 central switches , as "a way in" for mystery current , by leaving one /or /other off and see if still trips.
(also watch supply volts-)
----Dafter thoughts---
One piece of equipment may be clever and shut down if volts are too low...Messily.
Any security ,daylight sensitive lights turning off ?

 

[GBDamo]

Whats on the C20 breaker?

If you can leave it off and see if RCD still trips.

Could be compression fault, as the sun comes up and the building expands, a cable somewhere is pinched and trips causing both on earth and short circuit fault.

 

[Toneyz]

I went to a house that had the same problem every morning the RCD tripped it turned out that every morning her husband had a shower in the master ensuite and water was finding its way past the tray seal through the joint in the floorboards and into the garage batton holder.

 

[Des 56]

Link to a previous discussion
This

 

[pgrbff]

I went to a house that had the same problem every morning the RCD tripped it turned out that every morning her husband had a shower in the master ensuite and water was finding its way past the tray seal through the joint in the floorboards and into the garage batton holder.

Wiring in Italy is all in conduits. As you build/rebuild walls are chased and conduits installed. 99.9% of floors are solid so conduits are laid before floor is poured. When the general building work is finished the electricians use a fish to pull the wiring which is always stranded here, through the conduits. If the distances are long you have to install larger intermediate boxes throughout the building.