Shockwave,
In a previous life, I worked in product development at a place that made cameras to be mounted on vehicles, inside & out. IP67. To test the design, we'd immerse the cam in 3ft of water for 30 minutes. The design passed.
The cam had a 3.5ft pigtail to the connector. Not an RJ45, but a sealed IP67 connector. Long story short, the mating portion of the connector was sealed. (The M & F electrical contacts were kept dry.) However, we found water was getting under the cable jacket. Water travelled down the cable. The insulated twisted pair conductors were fine, the copper didn't get wet. But the jacket acted as a pathway for water to enter the camera.
Only some of the multiple cameras mounted on the vehicle were getting condensation inside the camera. We'd replace the cam, and the problem would re-appear later. WTF? Why would that happen? We pulled our hair out (with help from the customer)
Who woulda thought water could travel 3.5ft down a cable that had an extruded jacket? Well, it can. The twisted pairs contains enough space between conductors. The camera's thermal cycles probably created an atmospheric pressure difference as well. The rest was probably capillary action. Only the cams with connectors exposed to water had condensation. In hindsight, we should have guessed.
So my hunch: Check where the connections reside. Could moisture enter the connectors, then travel inside the cable jacket, past all that silicone at the camera's mounting location, and continue into the cam?
The IP pigtail is a round, extruded jacket cable. Probably PVC jacket. The round semi-outdoor RJ45 female has a hard plastic headshell. The headshell-to-cable junction is impossible to seal easily. (PVC to Plastic interface) I don't remember seeing any sealant between the two materials on my Dahua dome. If the connectors were stuffed into a soffit, maybe water is getting in there from rain gutter overflow? Maybe the temp difference between the cam (outside) and connectors (inside the soffit) leads to moisture wicking down the cable and into the camera? The cable jacket is sealed to the dome base - but water inside the jacket could travel right past?
Good luck.
Fastb
