power cable wall depth and fires

[Bobisme]

Generally i run cables under a wall parallel to a passage 'generally' 
I was wondering on the fire protection when having them buried deeper into the wall?
so instead of having them under the first wall they are under the second?
if they are behind a wall not just under one no fire right?

Would that negate the Zzzzt? 

[erdrik]

It would not negate the Zzzzt, but it would prevent the fires so long as the explosion was not sufficient to destroy the walls. It would also make repairing the conduit and the walls more difficult, requiring that you first tear down the outer wall(assuming it wasn't destroyed) to get to the inner wall. If you ignore the damage the next Zzzzt at that location might destroy the conduit.

[Bobisme]

cheers