Perforated Cable Trays Vs Rodents

Trunking systems aren't always impervious to rodents ... mice can get through holes as little as 6 mm in diameter, which would certainly achieve the minimum for surfaces  of IP2X/IPXXB (except, of course the top surface which would have to be IP4X/IPXXD).

IP XXD or B are is also certainly not mouse proof - both permit finger or thin screwdriver access, so long as the finger or spike does not touch anything that can come live - so can touch things like cables or other covers that are single insulation.

The hole can be any size or shape that does not admit a 34.8mm diameter ball for IP XXD - so a 34.7mm slot a metre long would do, or for IPXXB  a 50mm disk so perhaps a 49mm wide slot. 

Arguably minitrunking with the lid off and insulated singles exposed to view meets IPXXB or even D ...
and is really a bit poor for the top of anything. The wording of the regs suggests near equivalence  between IP4x and IPXXD, and really there is not. The IP (number) requirements are far tighter. 

Mike

IP XXD or B are is also certainly not mouse proof - both permit finger or thin screwdriver access, so long as the finger or spike does not touch anything that can come live - so can touch things like cables or other covers that are single insulation.

The hole can be any size or shape that does not admit a 34.8mm diameter ball for IP XXD - so a 34.7mm slot a metre long would do, or for IPXXB  a 50mm disk so perhaps a 49mm wide slot. 

Arguably minitrunking with the lid off and insulated singles exposed to view meets IPXXB or even D ...
and is really a bit poor for the top of anything. The wording of the regs suggests near equivalence  between IP4x and IPXXD, and really there is not. The IP (number) requirements are far tighter. 

Mike