Best way to deal with condensation in IP67 project boxes for outdoor sensors?

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1

Hi everyone, Working on an ESP32-based garden monitoring system. I’m using a standard IP67 plastic enclosure, but I’ve hit a wall with cable entry points.

Last week, moisture crept in through the PG glands I was using for the power and sensor leads—I suspect the seal didn't hold up under the temperature swings here. I’m thinking about switching to dedicated inline IP68 connectors (the screw-lock types) to make the whole thing modular and hopefully more reliable than just stuffing cables through glands. Has anyone here used the M20 series or similar for 12V/5V lines? Specifically, do they really hold up in heavy rain, or is it better to just go with a waterproof junction box and potting the whole board?

Any brand recommendations that won't break the bank but actually seal?

2

I've used these (panel mount + cable pair). I think they are very good quality for the price. They appear to seal very well, but I've not tested how waterproof they are.

3

All weather ebikes use "YLS" connectors which are waterproof (really), but use a knurled thumb screw for vibration. (Overkill)

The second best connector is Julet. Water resistant. "Snap together" and various wire counts.

Find the "extender" version of the pin count to get bith male and female connectors in one.

4

Check out what RV Solar guys are using. When I had mine I had a box on the roof with breakers and fuses and all the wiring went through it. I forget the exact name, but something like distribution box?
They have to be waterproof while doing 60mph/100kph down the highway.
Check on-line solar vendors or Amazon.

5

If you can, let gravity help. Make all thru box points on the bottom of the box with drip loops for any wires that have to go other than straight down.

6

Found the Amazon link. It's called a Solar Combiner.

Canadian Amazon Link

7

During my career I used through the bulkhead solutions from Pave Technologies. However, in the interest of economical you can roll your own with a trip to any home improvement or hardware store. The link shows through the bulkhead so you need a few pipe fittings and some epoxy.

I would also add a few desiccant packets inside your project box.

Ron

8

If the box only has to be rain proof, then leave a breathing hole in the botton.
Air tight is the worst thing you can do.
TV masthead amplifiers have semi-open bottoms and last like this for many decades.
Just try to keep the spiders out.
Leo..

9

Moisture or water? Title says condensation...

10
  • PG glands CAN be air and water tight, but don't count on it. If your gland is at the underside of the box, no water will enter here.
  • Bigger boxes may suffer from too much pressure difference, sometimes a little hole or a specialized item is added to allow breathing.
  • As your circuit uses power, however little it is, it's slightly warmer than everything else so condensation will not occur on it.
  • If your box need to go underground the problems are bigger.