foul_owl
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Running an RPI outside?

Wed Jun 12, 2019 5:21 am

I have an outdoor grade extension cord, but how do you get from the extension cord to the rpi? I was going to 3d print an enclosure but I'm guessing no common wall wart style supplies are rated for outdoors.

I'm guessing the usb connector needs to be completely sealed so I'm planning on that and not worrying about it, just need to deal with the power supply. What do you use?

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Imperf3kt
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Re: Running an RPI outside?

Wed Jun 12, 2019 7:47 am

foul_owl wrote:
Wed Jun 12, 2019 5:21 am
...I was going to 3d print an enclosure...
In my experience, 3D printing is far from weather proof.
For one some plastics used in 3D printing are biodegradable in water, for another, the prints are never 100% infill, they're hollow, usually around 20% fill, meaning water can just pass right through.
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rpdom
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Re: Running an RPI outside?

Wed Jun 12, 2019 8:01 am

Imperf3kt wrote:
Wed Jun 12, 2019 7:47 am
In my experience, 3D printing is far from weather proof.
For one some plastics used in 3D printing are biodegradable in water, for another, the prints are never 100% infill, they're hollow, usually around 20% fill, meaning water can just pass right through.
Totally. I tried 3D printing some water bowls for spiders and they leaked like anything, even on the densest settings.

foul_owl
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Re: Running an RPI outside?

Wed Jun 12, 2019 8:06 am

Please don't worry about the 3d printed aspect of this, my tests have been completely water tight.

Plus primer, several coats of paint, and several coats of polyurethane. It will be fine.

What about the power supply though?

Andyroo
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Re: Running an RPI outside?

Wed Jun 12, 2019 8:23 am

Do you have enough space for something like https://www.screwfix.com/p/masterplug-w ... -kit/46169

I do not like mains outdoors even in ‘weather proof’ boxes (that are only resistant) even with a RCD breaker.

Remember to put a drip loop on the bottom of the cable when you feed it into the box and possibly put holes in the bottom of the box to allow the water to drain out :shock:
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Imperf3kt
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Re: Running an RPI outside?

Wed Jun 12, 2019 8:53 am

foul_owl wrote:
Wed Jun 12, 2019 8:06 am
Please don't worry about the 3d printed aspect of this, my tests have been completely water tight.

Plus primer, several coats of paint, and several coats of polyurethane. It will be fine.

What about the power supply though?
Just thinking safety first here. Water ingress will destroy your Pi (and probably a few other things) if it isn't taken into consideration.
There have been numerous posts here by folks who put their Pi outside in a "waterproof" box and somehow short-circuited it with water.

Did your tests include long term? The materials might repel water -now-, but what about after a month or two? The materials you listed are hygroscopic meaning they'll eventually absorb moisture and could cause problems if not planned for.
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Re: Running an RPI outside?

Wed Jun 12, 2019 8:58 am

Given that the Pi will not be in a sealed box have you thought about condensation during damp weather?

To protect cable outlets (in the days of twin-ax) our recovery point was fitted with a small heater to keep damp out of the ends and that worked fine for over 10 years.
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davidcoton
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Re: Running an RPI outside?

Wed Jun 12, 2019 9:04 am

To back up the info above:
  1. You MUST use an RCD at the source of an outdoor mains supply.
  2. You should look for a commercial IP67 enclosure for all the mains components. With care and a large case you can put the Pi in there too.
  3. Don't forget the drain hole -- no bigger than 2mm diameter, though, to stop many insects getting in.
Rant: Of course the drain hole destroys the IP rating. But experience shows that water gets in anyway (eg condensation, atmospheric pressure changes) and it really needs a way out.
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Andyroo
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Re: Running an RPI outside?

Wed Jun 12, 2019 9:08 am

As for drain holes I’ve used plastic canvas (granny grating), car body repair aluminium mesh and bits of off cuts from ladies stockings before now to cover the holes.

Just run a bead of glue on the outside and stick the covering over the hole.
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rpdom
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Re: Running an RPI outside?

Wed Jun 12, 2019 9:10 am

Andyroo wrote:
Wed Jun 12, 2019 8:58 am
Given that the Pi will not be in a sealed box have you thought about condensation during damp weather?

To protect cable outlets (in the days of twin-ax) our recovery point was fitted with a small heater to keep damp out of the ends and that worked fine for over 10 years.
You won't need a small heater, the Pi will do that itself as long as it is powered.

What you will need is some drainage, as moisture will build up and you can't run a Pi in a sealed environment without some careful thermal management/heatsinkery.

As for power, as long as the whole unit is in an IP whatever (can't remember the exact rating for weatherproof) enclosure, you should be fine.

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B.Goode
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Re: Running an RPI outside?

Wed Jun 12, 2019 9:35 am

As for power, as long as the whole unit is in an IP whatever (can't remember the exact rating for weatherproof) enclosure, you should be fine.


It's amazing what you can learn by following up leads from these forums!

I had no idea that the two digits in an IP rating had discrete significance until I read this: http://www.enclosurecompany.com/ip-rati ... lained.php

I think the outdoor boxes I see in my local branch of Bodgers-R-Us have an IP65 label.

Andyroo
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Re: Running an RPI outside?

Wed Jun 12, 2019 10:16 am

Just be aware that an IPx5 to IPx7 does not mean that water will not get in - damp sneaks in anywhere...

Obviously any holes can invalidate the rating even if you use grommets in the holes.

One other point to note is to think about cooling - a watertight case is reasonably air tight so fans are just moving warm air around in the box. I normally like my Pi cooked but not like this :lol: :roll: :lol:
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TimG
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Re: Running an RPI outside?

Wed Jun 12, 2019 10:59 am

Re. power: To avoid putting mains power in a box exposed to the weather, I've used an old 18V laptop power supply in combination with a small regulator like these:
https://www.tracopower.com/products/bro ... egulators/

The 18V supply (the exact voltage isn't important) sits safely indoors, and the regulator lives outside near to the RPi connected by a long run of low-voltage cable. The drawn by the RPi fluctuates a lot, causing significant variation in the voltage drop across the long cable, so you really need that regulator. The regulator is a high efficiency switching type to keep down the heat dissipation inside the un-ventilated box.

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