Consumer units and equipment outdoors

GTB,

Happy to help. 

Simply the manufacturer's instructions reflect the sometime requirement to have a drain hole, otherwise why provide the option?  You select and erect as per environment and what is realistic; that comes from experience. The manufacturer accepts  the IP may be reduced due to the hole being made, but that is dependent on the likely hood  of a jet of water being fired up the hole of if the dust aspect is sufficiently arduous to cause a problem, so they qualify the note.

 We do not want to be unnecessarily prescriptive, nor does the manufacturer.

Most of these sockets end up on outside walls of houses, so unless it is a jet washing area such as decking, any notional reduction in IP , in respect of moisture entering from outside, is minimal , reflected in the guidance given by the manufacturer. IP55 may well still be more than adequate for where and how the socket is. Do not be tied to maintaining the sockets rated IP in all circumstances, unless it is absolutely required.

I thought the OP was generally about stuff being outside and subsequent IP ratings required or achievable,  not for when these accessories are installed in severe locations that actually do require IP66/IP67. 

When you were 16 and confronted with drilling a cable hole from inside to outside for wiring or wiring and containment, were you instructed to slope up or down or straight? Similarly, drilling a fan duct; what's your angle of attack?

GTB,

Happy to help. 

Simply the manufacturer's instructions reflect the sometime requirement to have a drain hole, otherwise why provide the option?  You select and erect as per environment and what is realistic; that comes from experience. The manufacturer accepts  the IP may be reduced due to the hole being made, but that is dependent on the likely hood  of a jet of water being fired up the hole of if the dust aspect is sufficiently arduous to cause a problem, so they qualify the note.

 We do not want to be unnecessarily prescriptive, nor does the manufacturer.

Most of these sockets end up on outside walls of houses, so unless it is a jet washing area such as decking, any notional reduction in IP , in respect of moisture entering from outside, is minimal , reflected in the guidance given by the manufacturer. IP55 may well still be more than adequate for where and how the socket is. Do not be tied to maintaining the sockets rated IP in all circumstances, unless it is absolutely required.

I thought the OP was generally about stuff being outside and subsequent IP ratings required or achievable,  not for when these accessories are installed in severe locations that actually do require IP66/IP67. 

When you were 16 and confronted with drilling a cable hole from inside to outside for wiring or wiring and containment, were you instructed to slope up or down or straight? Similarly, drilling a fan duct; what's your angle of attack?