I am currently working on an upgrade to a SCADA control system for a crushing plant in a quarry.
One of the big issues they face is dust, the PC sucks in massive amounts of dust every day and ultimately pays the price. My task was to come up with a fix that would prevent this from happening so regularly.
The best option would have been to install an industrial screen and a fanless pc all inside a sealed enclosure. However, the IT company provide a standard desktop machine.
This instructable will show the box I put together to help prolong the life of the control PC and monitor while maintaining usability.
The enclosure is not sealed and will let in dust but the aim here is a reduction in the amount of dust reaching the equipment and maintaining ventilation.
You can see from the images that the control room is very dusty, the screen shown had only been in the room for 24hrs and already had an unhealthy coating.
Step 1: Close Up the Box
I started out with a wall mounted 19" network rack with a glass door. The unit is 400mm deep and 800mm high (I think it was 15U).
As this box is designed to be wall mounted, the back is open. To remedy this, I made a back plate from an aluminium/plastic composite panel, this stuff is used for signage and can be cut with a knife.
Once cut to size, I drilled and screwed it to the back of the box, I had some sticky foam gasket for the edges just to close any cracks remaining after fixing.
Step 2: Create Some Ventilation
I had a 4 fan cooling unit from an older, larger cabinet.
These fans run directly on 230VAC so there is no need for a DC supply.
I removed 2 of the fans and fitted them to the fan ports on the top of the cabinet. I know what you are thinking, fans will suck in dust, but I am going to use them to blow from the top. The idea is that the fans will help to stop dust settling on top of the box and falling in, by blowing air out the top it will draw air through the side vents and hopefully not draw in too much dust, time will tell.
Be careful when wiring as this is a mains install and be sure to earth the casing as it is metal and a short would make the cabinet live.
I also in my silly DC mind installed the fans and they were running in the "suck" direction, I reversed the polarity but being AC still ran the same way so I needed to remove them and flip them over.
Step 3: Accessorise
I wanted to make the box as closed up and secure as possible.
I added a front mount shelf, being a network cabinet there are tonnes of cheap accessories out there.
The shelf will support 20kg which is way more than I needed.
I also added a 6 plug PDU (power distribution unit) again this is a standard network cabinet accessory.
This means I only need to run out 1 power cable, 1 network cable and the cables for the keyboard and mouse.
Step 4: Fill 'er Up
I put the PC in the back of the shelf and the monitor sat nicely to the front.
I had previously set the position of the front posts to allow the screen to sit at the front and the door still close.
I allowed the cables for the keyboard and mouse to pass under the door and set it in place.
The tinted glass of the cabinet door also makes the screen a bit easier to read when the sun shines in the window, bonus...