Will it be fire safe? (electric question)

[JoeJoe]

The electricity cupboard is at floor level in my hall. I just noticed today that the bottom has an openning of around 10cm x 10cm into the void under the floor to allow for the cables to feed through. The floor is suspended, and the cupboard door is not very tight, allowing for draft to come through.

Will if be safe (is it allowed) to stuff some rockwool in the opening? The way the cupboard is built it will probably require to fit a new one rather than replace the door, so I cannot see myself doing it very soon.

TIA.

[dennis]

If you put too much insulation around the cables you are supposed to de-rate them. How much depends on how many, how much insulation, load, etc. so it varies. I doubt if you would need to worry if you stuck 2" of Rockwool around the hole. It wouldn't burn as such anyway as PVC is self extinguishing and Rockwool doesn't burn but it would be expensive to fix if it all melted into one lump.

[meow2222]

If its only a few inches it makes no difference, copper is very thermally conductive.

NT