A Control Design reader writes: What type of electrical enclosure is best for high humidity and extreme temperature locations, such as near saltwater? Any recommendations on design, materials or other considerations?
For an enclosure in a hot, humid and possibly salty environment, I would suggest choosing a UV stabilized polycarbonate enclosure. An ingress protection rating of IP67 or IP68 is strongly recommended to ensure the best resistance to the elements. Verify that hardware is of high-grade stainless steel and that the gasket is of a silicone composition. I always recommend UL-listed enclosures from a reputable manufacturer when it comes to these types of extreme conditions to ensure the enclosure meets standards and the company will stand behind its products.
Other hardware attributes to consider include noncorrosive materials such as brass or zinc coating. Additional protections can include O-rings or plastic, rubber or silicone hole plugs. Pay close attention to torque specs if the manufacturer specifies torque ratings of fasteners, as under-tightening or over-tightening can both cause leaks or enclosure malfunction.
It is best to design the sealing area inside of the fasteners to establish the best sealing environment possible. If additional holes are necessary in the enclosure, be sure to match or exceed the IP rating of the enclosure by using IP-rated hole seals and grommets, or seal well with an environmentally resistant epoxy or silicone material. All enclosure assemblies should be properly tested prior to installation in the field to ensure proper fitment.
-Cody Knutson / product manager II / Digi-Key Electronics
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