Sun heat on caravan cable causing meter box circuit breaker to pop?

[TimGemm]

Whilst it can also be caused by normal corrosion, what you describe instantly red flags with me as a heat/overload situation. If there has been current passing to the earth (in the U.K. we call that the CPC) then obviously that will generate heat - except if the terminals haven’t been done properly (eg aren’t tight enough) then you can end up with some arcing which is normally where that discolouration in the copper comes from.

Are we talking New Zealand sun here?

It should be a specific cable for outdoor use.
Some domestic types, designed to be used in homes and buried in the fabric of the building will react to UV light over time, the plastic hardens and cracks.

The other issue could be overload. What size is the breaker, size of cable, load in caravan and distance between breaker and caravan.

Circuit breakers can also become weak over time… and will just trip for no reason.
From what I know of New Zealand electrics, is the meter box outside and maybe open to the elements? Has water got in somewhere?

Are we talking New Zealand sun here?

It should be a specific cable for outdoor use.
Some domestic types, designed to be used in homes and buried in the fabric of the building will react to UV light over time, the plastic hardens and cracks.

The other issue could be overload. What size is the breaker, size of cable, load in caravan and distance between breaker and caravan.

Circuit breakers can also become weak over time… and will just trip for no reason.
From what I know of New Zealand electrics, is the meter box outside and maybe open to the elements? Has water got in somewhere?

So it seems like the cable is damaged somewhere. Might have to replace. The max load is fridge + 2000W induction hob + 2000W oven. Cable is 100m long. Is 6mm2 cores enough? Cheers