Filling holes where cables etc. go through

[L-Grane]

Hi, I want to fill in some holes in the basement.
My idea is to take some fiberglass and push it in, then apply some plaster. Is it okay to do that? I'm mainly thinking about the electrical cables in case there's an electrical safety issue I'm missing. Should I split them and put some sort of conduit around them?

 

[G.L.]

Seems like a good idea. When the cables are not embedded, it's easier to pull them out if needed.

 

[useless]

Add some mortar and jiggle the cables and copper pipe before it sets so the holes become a few mm larger.

But you might want to start by securing all the cables.