Enclosure Design - Water Resistance CAT5 Ports

[Skyrocket]

After struggling with it for a year, here is my design for mounting my LOR controllers. I bought metal NEMA 3R enclosures from a local electrical supply house. Since my employer buys a lot from them, I got the cases for $17 each. List price is $46 each and the best I found on the Internet was $23 each. I was happy.:)



I drilled holes in the bottom of the cases for the power cords. After de-burring, I coated the bare metal with instant galvanizing spray (Lowes) (used a Q-tip) to stop rust. Rubber grommets protect the power cords from chaffing and keep water out. It is not waterproof but it allows for the case to breath a little which should prevent condensation. If necessary I could always mount a resistor to the side of the boxes to act as a heater.



As for the CAT5 cable, I punched holes in the side of the cases with a Greenlee punch and mounted ½” PVC plastic conduit fittings. I made gaskets from large rubber washers to help seal the joints. The conduit fittings have a 5/8” dia ID hole which mates nicely with the 5/8” OD rubber feet I had around the house. Yes, it pays to be a pack rat sometimes. All I have to do is insert the CAT5 connector (RJ45) through the PVC connector and plug it into the board. The rubber foot is then pressed into the PVC connector (not all the way) to make a nice tight fit. I also sanded a bevel on the PVC connector to make a type of drip edge and keep water from accumulating in the PVC connector. Just screw on the case cover and that’s it.



Since the CAT5 cable fits tightly in the rubber feet, I used a LITTLE oil to lube the cable and then wiped off the excess.



This may not be quite as good as the waterproof RJ45 connectors ($10 each minimum) but for less than $1 per connector ($2 per case) it is a lot cheaper than $20 per case. If you are doing multiple controllers it adds up quickly. This design should do quite well for the application.



Below are some pictures of the case and the cable details. I hope this idea helps others who have worked on the same problem.



Roger


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