RJ45 cable glands (2023-2024)

The RJ45 cable glands provide a water-tight connection between the scarecrow, the control box, and the Cat5 cable that connects them. (RJ45 is the designation of the rectangular 8-conductor plug and jack; Cat5 describes the cabling used.)

If water gets in to the RJ45 jack inside either cable gland, it can create short-circuit that will potentially put 12V power onto the lines that carry control signals directly to the 3.3V microcontroller. This damages the microcontroller such that it will subsequently draw too much current, overheating its own power regulator which can get very hot. 

An additional concern is that if the body of the cable gland is tightened or loosened without first loosening the dome, it will twist the cable still plugged into the jack, very possibly causing damage to the cable. 

So, it's important to be able to assemble and disassemble the cable glands properly. (To remove the cable from the jack, you will need to depress the latch on the plug. This is awkward inside the cable gland body, but one of the pipe shims can reach or maybe even your pinky finger.)

The following text and images are found in section 5.3 of the 2024 Model Operation Manual; the photos are reused from stage 3 (3.6 and following) of the 2023 Model Assembly Instructions, 

Control cable connections

Power and control signals reach the scarecrow from the control box using an outdoor-rated Cat5 cable which may be removed for convenience in transport and storage. Weatherproof sockets are on the scarecrow and the control box; the provided cable has a cable gland at either end to screw into these. The cable works in either direction; the ends are the same. The following image shows the parts of the cable gland separated. You do not need to fully remove the dome nut and so the elastomer (which provides the watertight seal around the cable) will remain inside the claw of the body.

⚠️ Caution: to avoid damage to the wires inside the RJ45 plug, always make sure the dome nut is loose before tightening or unscrewing the cable gland body. To avoid damage to the gasket, do not over-tighten the cable gland body.

To reattach the cable to the bucket, first loosen the dome nut so that it can freely slide over the cable. Insert the RJ45 plug into the RJ45 jack on the bucket; you should hear a distinct “click” as it locks in place (A). Fully finger-tighten the cable gland into the RJ45 jack housing while holding the housing (B) and then fully finger-tighten the dome nut while holding the cable gland (C). Verify that the cable is secure (D).

The process for connecting the cable to the control box is essentially the same: