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?

 

[micknew]

We always drill a small drain hole in bottom of any any external connection enclosure even floodlights as seen them fill with water so many times.
The factory seals on most enclosures do not seem to be up to the required standard.
Never had call back to connections after drilling a drain hole.

 

[Knobhead]

I would drill a drain hole. Weatherproof fittings make great water tanks. Keeps things cool until it goes bang. A bit of ventilation stops condensation as well.

As to the socket what are you trying to avoid drilling, the socket back or the column?

 

[Engineer54]

Drilling a drainage hole in high IP rated enclosures, is for condensation purposes, not for compensating for badly sealed glanding. Holes are drilled when these totally sealed enclosures are mounted/located in positions that will be subject to the occurance of condensation forming on the interior of these enclosures. In most circumstances this shouldn't de-rate the enclosure in real terms, as the usually 3.5 or 4mm hole is located at the back edge at the bottom of the enclosure....

 

[Piratepete]

As to the socket what are you trying to avoid drilling, the socket back or the column?

Hi Tony
Thanks for your reply. It's the column I don't want to drill.
Pete

 

[Marvo]

Where I am if you drill drain hole it will be full of insects in no time. This often causes more problems than water ingress. I would rather use the correct gland for the cable and one of the same IP rating as the enclosure it's going into. You do get glands specifically for flat profile cables. Also only gland underneath the enclosure.

 

[Piratepete]

Where I am if you drill drain hole it will be full of insects in no time. This often causes more problems than water ingress. I would rather use the correct gland for the cable and one of the same IP rating as the enclosure it's going into. You do get glands specifically for flat profile cables. Also only gland underneath the enclosure.

Hi Marvo
Wee beasties does bother me, though I haven't so far come across a problem with them
Glands for flat cables - where from? Bottom only entry. I agree, but life doesn't always let us - often have 3 cables exiting.

I think Tony and Micknew, above, have hit on the big problem - the accessories don't seal the way that they're meant to - this includes well known makes as well as the more obscure and cheap n cheerful.
Pete

 

[Silly Sausage]

It does seem to be a daft thing to do...drill a hole in 'watertight' box. Trouble is (I think) water vapour can sneak in through the tiniest of gaps, condenses inside & then the water can't get out!

 

[D80]

As pretty much already said, I drill a drain hole to give any water a way out rather than keep it locked in. 3-4MM should keep them bugs out around here.

 

[D80]

Should add, I used to work a little bit in food factories, and with there chillers keeping the food storage areas cool used to find an office area stuck beside it all the fittings and conduit just filled with water through condensation in no time at all.

 

[jase]

It's got nothing to do with the effectiveness of the glands so scillicone will not help, as engineer 54 has said, it is a condensation issue,

 

[Mr.Si]

Was chatting to my wholesaler this very week about this very thing as he had asked his sparks to put a drain hole, bit he hadn't done it. A few seasons later his kitchen ring (where it was spurred from) was tripping because it was letting water in via a badly fitted ip68 connection.

Certainly made me think. I doubt everyone does it, but it makes sense. However, i recon the wee beasties would get into a 3mm hole no problem.




Sent from my Samsung Galaxy S II via Tapatalk

 

[Silly Sausage]

However, i recon the wee beasties would get into a 3mm hole no problem.

As long as they're not earwigs, horrible things!

 

[D80]

As long as they're not earwigs, horrible things!

Probably just not big enough to get electrocuted either. Although 2 of them together maybe could go across L&E - I'd call that a result and all the more reason to drill drain holes!

 

[wildgoose]

Personally I will always drill a small drainhole in the bottom corner of the IP enclosure if I fit it outside or in damp environment. The exception would be if the IP rated box is of high quality or if it likely to be sprayed or jetwashed.

Worked in another safety critical industry previously, where keeping moisture out proved to be very difficult. If you get temperature changes then natural condensation will build up inside enclosures which screws up electronics. Most reliable solution is to completely fill with good quality potting compound or sealing it with a vacuum - not really practical for the applications being discussed!

Stick with small drain holes and keep your fingers crossed that the little critters don't make their nest in there!!!!!

 

[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