Drain holes in Weatherproof Accessories?

[Piratepete]

Hi Guys
I fit a lot of IPX5 and IPX6 accessories and wonder if I should be drilling a drain hole at the spot that's usually indicated. Most have instructions that have no guidance except to say that the IP rating will be compromised if you drill a drain hole.
However the instructions with a make (rated IP55) new to me say that a drain hole is required if cables are glanded from the top or side and also if the bottom entry gland completely seals!

The question has added urgency since opening an IP66 adaptable box I installed some years ago (with side entry) and finding it half full of water! I 've always doubted whether the standard compression glands seal on flat cable. The downside for drain holes is they let the wee beasties in.

What do you do? Is there guidance anywhere on this? Started putting a blob of silicon at the gland entry now!

Cheers
Pete

PS. Whats a good way to fit a weatherproof double socket to a vertical steel column without drilling it? Any suitable clips around?

 

[HandySparks]

Just to add to what wildgoose says above, even if rain doesn't leak in, changes of ambient temperature cause changes in internal air pressure which sucks damp air in through the tiniest of holes. This causes condensation inside and, if there's no drain hole, the water just builds up until it causes trouble.

I always drill a small drain hole in exterior enclosures. It's just about impossible to hermetically seal an enclosure. You may fit suitable cable glands but can you be sure that there's a good seal between gland body and the enclosure?

 

[Marvo]

Glands for flat cables - where from?

Most decent cable glands have different compression rubbers available for the same gland body. Here's a link to Pratley which we use but I'm not sure how available this particular make is in the UK. Lapp also make similar and also Altech.

I'm very surprised about it being common practice to drill drain holes in boxes and enclosures, I'm guessing this is a symptom of poor quality boxes being widely distributed and used nowadays. I can believe that insects aren't as much a problem in the UK but one thing I don't understand is why even bother paying the extra for an IP 65 or 66 box then effectively convert it into an IP4x one by drilling it? Why waste the money? You may as well just use an IP44 in the first place and just arrange the wiring inside so it doesn't get wet.

 

[Octopus]

TLC Direct sell Pratley products in the UK - not all are on their website so a phone call is required.

 

[Engineer54]

I'm very surprised about it being common practice to drill drain holes in boxes and enclosures, I'm guessing this is a symptom of poor quality boxes being widely distributed and used nowadays. I can believe that insects aren't as much a problem in the UK but one thing I don't understand is why even bother paying the extra for an IP 65 or 66 box then effectively convert it into an IP4x one by drilling it? Why waste the money? You may as well just use an IP44 in the first place and just arrange the wiring inside so it doesn't get wet.

Depends very much on the location where the box/enclosure is mounted. In situations where there are constant temperature changes then drilling a drain hole or complete compound filling is the only answer. I've seen many a IP 68 enclosure that has suffered corrosion damage to terminals, or had water (condensate) being trapped in them. And these were in countries with low, low rainfall, so purely down to condensation.

I'm pretty sure that the manufactures enclosed instructions with all these IP rated accessories or boxes/enclosures recommend drain holes being provided in circumstances of high probability of condensation levels...

 

[Spazz]

I have seen some watertight seals which act as a drain as well, Car ECUs use them mainly.
They are a water tight gromit which sits where you want the drain to be, and they stop water from coming in, but they let water out.

They have like 2 little lips (best way to explain them) which in their normal position they are tight shut, but when water from inside the enclosure touches them it lets it drip out slowly at the same time as keeping a water tight seal.

Here's a picture of one
View attachment 10500

They are mainly used in the car industry to keep water out of electrical components like ECUs, Starter motors, Alternators, etc.

They should work as we are not coming into contact with electric with them, they are a simple drain to stop water coming in, but letting water out

 

[Engineer54]

Your attachment isn't working!!

 

[Marvo]

....drilling a drain hole or complete compound filling is the only answer.....I'm pretty sure that the manufactures enclosed instructions with all these IP rated accessories or boxes/enclosures recommend drain holes being provided in circumstances of high probability of condensation levels...

I think we're just going to differ in opinion on this one. If manufacturers recommend a drain hole (I haven't come across any recommendations like this) I'm sure they'd put on in or at least provide a knock-out option for one in the casting or moulding. I also can't help thinking a drain hole would accelerate corrosion by allowing a constant supply of oxygen into the box. If the box wasn't compromised by a hole drilled then no fresh air = very little corrosion

I have seen some watertight seals which act as a drain as well, Car ECUs use them mainly. They are a water tight gromit which sits where you want the drain to be, and they stop water from coming in, but they let water out........

These devices (duck bill valves) would make sense to me in an enclosure, at least the original IP integrity might be maintained or at worst it would solve the insect problem.Hmmmmm, maybe a business opportunity for some budding entrepreneur there??? Come up with one that can be fitted into a standard IP 66 20mm gland by removing the compression seal. When you make your millions you can just throw 1% royalties my way.

**Edit**
I see there's very similar products already available.

 

[Engineer54]

Marvo,

The manufacturers DO mark the positions for drain hole in there IP boxes etc!! They do work too, for these enclosures that are subject to large temperature changes, such as cold nights and hot days...

I've no idea what the conditions are in SA, but for example the Middle East can be very prone to condensation in what are virtually sealed enclosures. Nothing to stop you using these product that allow moisture build-up to freely escape though. Perhaps they could/should incorporate these things in the accessories they normally provide with outlets and switches etc...

 

[wildgoose]

Nicholas Owen Wrote "They have like 2 little lips (best way to explain them) which in their normal position they are tight shut, but when water from inside the enclosure touches them it lets it drip out slowly at the same time as keeping a water tight seal".

This design is also used extensively for HVAC condensate drains - Known in the automotive industry as "Donkeys Dick Drains" - True!!

 

[beatboaby924y]

Hi

You should be using IP rated washers with your glands. That should stop water ingrese by way of the glands.

As for drilling the drain hole I would alway drill one unless theirs a chance the enclosure could be sub merged in water.

 

[Spazz]

The only problem with these Donkeys Dick Drains is that they need cleaning every 9 months or so, as you get dirt and stale water glue them together - all they need is to be squeezed on both sides using your figures and pull down - not to hard that you pull them out. - lol

They usually fit on pipe outlets, to allow them to work properly

I cant seem to find them anywhere though to buy them???

Might have to go to a scrap yard and pinch a few - lol

 

[Piratepete]

Thanks Guys
This has been a fascinating thread. Wee beasties versus water/condensation problems.
I think the holes win!
FYI, BG and LAP recommend the holes. Others have drain hole locations but no guidance, others have no holes marked at all and no guidance.
Cheers
Pete

 

[Silly Sausage]

Thanks Guys
This has been a fascinating thread. Wee beasties versus water/condensation problems.
I think the holes win!
FYI, BG and LAP recommend the holes. Others have drain hole locations but no guidance, others have no holes marked at all and no guidance.
Cheers
Pete

Aye, beasties every time. Water is everyone's enemy, apart from plasterers.
We'll all be b@ggered when the beasties get a taste for PVC though.

 

[wildgoose]

On the MK Masterseal range, which is really good quality, they supply a diagram showing the drill point location on enclosure for a drain hole.

 

[Marvo]

On the MK Masterseal range, which is really good quality, they supply a diagram showing the drill point location on enclosure for a drain hole.

What IP rating are they? Do they warn you that drilling a hole might reduce the IP rating?