D
Darkwood
As it stands we can help you by suggesting what could be the cause and because you are DIYer we can only advise on possible appliances that you can unplug and try to eliminate but lets make it clear that you are playing with very dangerous voltages here and you have taken the cover off and exposed live busbar rails given the position of the main switch is ON.
The advice to you is try unplugging various items for say a week at a time overnight and see if you can clear the issue, if this fails then you need to get a competent person in with the correct meters to check your circuits.
Just remember at domestic voltages it can easily kill you even with one small shock so ensure all covers are back on and see if you can resolve this without the need to expose live parts.
I would also check to see what the weather is when it has tripped, is it windy, is it or has it been raining, these would possibly lead to possible causes like exterior lighting, garage/shed power etc etc I would also list everything that is on when it trips, are you running the washing machine overnight?.. it may trip on a particular part of the cycle, these are easier issues to verify of what can be a lengthy issue to diagnose and trace given it is intermittent.
The advice to you is try unplugging various items for say a week at a time overnight and see if you can clear the issue, if this fails then you need to get a competent person in with the correct meters to check your circuits.
Just remember at domestic voltages it can easily kill you even with one small shock so ensure all covers are back on and see if you can resolve this without the need to expose live parts.
I would also check to see what the weather is when it has tripped, is it windy, is it or has it been raining, these would possibly lead to possible causes like exterior lighting, garage/shed power etc etc I would also list everything that is on when it trips, are you running the washing machine overnight?.. it may trip on a particular part of the cycle, these are easier issues to verify of what can be a lengthy issue to diagnose and trace given it is intermittent.