Consumer units and equipment outdoors

As a poor mans weep vent and insect excluder, a  short length of plastic tube in a stuffing gland, with a twizzle of glass fibre loft insulation inside will keep the ants out.

Actually the main thing with ‘sealed’ boxes is not really condensation, but pressure equalization between inside and out. On hot and cold days a sealed box of air will be considerably stressed once it is not at temperature it was sealed at, and those stresses (forces) can cause strains ( flexing and deformation) allowing water to be drawn in around the lid joints and seals on glands etc. A box with a puddle of dew on it in a cold morning, with a partial vacuum inside is  very vulnerable to this. Removing the pressure difference helps a lot. It also stops water being wicked along between the wires of flexible cables, which can be an issue.

Other things that help a lot are even the simplest of protections like a canopy or porch, so the dew does not settle on it and the sun does not beat down and de-nature the plastics and peel the paint.

I have seen the use of a second meter box beside the first one, one for the DNO one for the customer kit as a way to do this. However I've also seen the effect of the door being removed/smashed on one in an exposed location and it raining in for a few weeks, and it  is not at all pretty.

Mike.

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?

Alcomax: 
 

 

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. 

 

Hang on … I made the point that a 5  mm drain hole can cause problems even where there are not “severe locations” … but also so can “tight sealing” to IP65/IP66 without ventilation … again no “severe location” … and mentioned the drain plug in the first place.

I think that GTB was only pointing out a few different options available where there are  additional constraints, in addition to another point, which I think the point you've perhaps missed completely: that the 5 mm drain hole is OK in many indoor locations with conduit (to stop condensation) … outdoors, if you have a conduit install, you need an appropriate drain plug (but you might need one anyway because of internal condensation due to pressure and temperature changes) !

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.

Conduit coming from above, behind or sides will also bring condensation as above. It does depend on how exposed the side of the house is … I wouldn't generalise.

Where insects enter an outside accessory they just die and dry up and become harmless insulating dust.

The drain holes in say an M.K. Shield outdoor socket that boasts IP56 has a drain hole that faces backwards against the wall with a plastic obstruction to prevent the ingress of water. I have never had any problems when I always drill a drain hole in seaside locations.

Z.

GTB: 
 

Alcomax, Zoomup,

Thanks for the instructions on the MK Masterseal unit, but read the wording carefully (Note 3) the drilling of the drain hole (5mm) is ONLY when you have conduit entering from the top or side entries. So conduit from the bottom, or any type of cable gland entry the Note 3 does not apply. Reason being the conduit is a hollow tube and conden

IP66 as I have mentioned before is dust tight, i.e dust cant enter, so with the definition of dust as “finely divided solid particles, 500 μm or less in nominal size, which may be suspended in air, may settle out of the atmosphere under their own weight” then I doubt your small drilled hole 3 or 4mm would prevent dust entering, if you have conductive dust then that starts all sorts of other issues when it settles over a period of time on the insulating surfaces/contacts within the enclosure.

 

I mainly install 13 Amp weatherproof sockets on house walls for use of equipment outdoors.

What kind of conductive dust are you referring to? I can't think of any in my experience.

Also, for any dust to enter a sealed enclosure with just one small drain hole at the bottom an equal amount of air has to escape from the same enclosure. This can not happen. There is not convection air movement.

You are worrying needlessly.

Z.

Zoomup: 
 

Where insects enter an outside accessory they just die and dry up and become harmless insulating dust.

The drain holes in say an M.K. Shield outdoor socket that boasts IP56 has a drain hole that faces backwards against the wall with a plastic obstruction to prevent the ingress of water. I have never had any problems when I always drill a drain hole in seaside locations.

Z.

Only joking with the above article, but I've seen a lot of what the wind blows in through 1 mm holes!

Sand is OK, but when salty air gets in, that causes premature corrosion, and it's made worse with the evaporation/condensation cycle.

gkenyon: 
 

I think you have missed the point of my whole post, in that a drain hole may well be required and the decision is not simply based on hole = bad, no hole = good; now that is a generalisation - a charge that cannot be attributed in any fathomable way to

          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.

 As the issue from some seems to be a simple drain hole compromises the IP65/66 rating, what would appear to be an IP55 “drain vent plug” will do that anyway. But that is not really the point is it, as the decision on what you do to the enclosure is formed by the likely site conditions and its intended use and this is reflected in the notes in the manufacturers instructions.

In any event, why be tied to “5mm hole”?  It is not something I mentioned. A smaller hole may suffice.  Why this fixation with conduit? My alledged generalisation  will be familiar to those that have been asked to install an outside socket on the rear of houses, usually back to back to an existing internal one with the slope of the cable run being to the outside and then the new socket being the lowest part….

Zoomup: 
 

GTB: 
 

Alcomax, Zoomup,

Thanks for the instructions on the MK Masterseal unit, but read the wording carefully (Note 3) the drilling of the drain hole (5mm) is ONLY when you have conduit entering from the top or side entries. So conduit from the bottom, or any type of cable gland entry the Note 3 does not apply. Reason being the conduit is a hollow tube and conden

IP66 as I have mentioned before is dust tight, i.e dust cant enter, so with the definition of dust as “finely divided solid particles, 500 μm or less in nominal size, which may be suspended in air, may settle out of the atmosphere under their own weight” then I doubt your small drilled hole 3 or 4mm would prevent dust entering, if you have conductive dust then that starts all sorts of other issues when it settles over a period of time on the insulating surfaces/contacts within the enclosure.

 

I mainly install 13 Amp weatherproof sockets on house walls for use of equipment outdoors.

What kind of conductive dust are you referring to? I can't think of any in my experience.

Also, for any dust to enter a sealed enclosure with just one small drain hole at the bottom an equal amount of air has to escape from the same enclosure. This can not happen. There is not convection air movement.

You are worrying needlessly.

Z.

 

The dust needn't be conductive when dry, but a build up of it can affect creepage/clearance distances, especially if you get conductive dust or moisture on top of the dust.

The standards take account of an assumed contamination environment, but whether it's the same as the one you've installed in is another question.

Alcomax: 
 

 As the issue from some seems to be a simple drain hole compromises the IP65/66 rating, what would appear to be an IP55 “drain vent plug” will do that anyway. But that is not really the point is it, as the decision on what you do to the enclosure is formed by the likely site conditions and its intended use and this is reflected in the notes in the manufacturers instructions.

In any event, why be tied to “5mm hole”?  It is not something I mentioned. A smaller hole may suffice.  Why this fixation with conduit? My alledged generalisation  will be familiar to those that have been asked to install an outside socket on the rear of houses, usually back to back to an existing internal one with the slope of the cable run being to the outside and then the new socket being the lowest part….

 

All boils down to what IP rating you need.

Drilling the hole, even a 0.5 mm hole, drops the IP rating to IP4<something> - possibly IP45 if the hole is suitably placed. Quite simply, because IP5x requires filters (or solid panels) and dust seals.

Whilst we often talk about “IP43 minimum” for outdoors, I think you're missing completely the fact that in many cases this is woefully below what is needed in the real world - it's OK under a shelter in some places.

Around the outside my house, and in the garden, we've found IP43 and IP44 totally useless - stuff only lasts a couple of years at the most. The wind sees to that, even where the vents or small openings are on the rear.

        All boils down to what IP rating you need.

Bingo!     ?

The wholesalers previously stocked many variants of “outside socket”.  The posh [expensive] were IP65/IP66 the cheaper IP55 and the nasty IP44, which was only really for a grotty outbuilding not exposed to anything except mouldy air.   Now as there seems to be cheaper competitors to the masterseal , there seems to be only IP65/IP66 available. But of course, that could be seen as over the top for certain applications.  

        Drilling the hole, even a 0.5 mm hole, drops the IP rating to IP4<something> - possibly IP45 if the hole is suitable placed. Because IP5x requires filters.

Whilst we often talk about “IP43 minimum” for outdoors, I think you're missing completely the fact that in many cases this is woefully below what is needed in the real world - it's OK under a shelter in some places.

Around my house, we've found IP43 and IP44 totally useless - stuff only lasts a couple of years at the most. The wind sees to that, even where the vents or small openings are on the rear.

The market is the real world. What sells is produced in volume in order to make people price happy. The market dictates IP44 is sold as suitable for “outside” use, as it is; but not for totally out in the open use or all environments. You may find that the old, pre LED type security floods, though likely to rust solid, would function for  several years, though only IP44.  I have found that the cheaper end of the LED security floods, being sold as IP44 fail miserably on an outside wall, in comparison to the old redundant halogens. But these are done to a price. The IP65 versions are eyewatering and a hard sell ; a stand alone IP65 LED flood and separate IP44 PIR sensor is a cheaper combo and a compromise.