Not all drip loops are created equal.

I’ve recently been working on a weather-sealed cabinet on a pole where the rubber seal through which cable entered the top part of the cabinet has atrophied in the sun.

Because there was no drip loop in the cable – the original integration team just went into the cabinet on falling angle, over time the cabinet has slowly filled with water, killing the controller and comms module inside. Is there an ideal drip loop shape in your opinion, or is a simple downward convex curve enough?

A: A simple curve downwards is enough. Gravity will do the rest, pulling water off the cable at its lowest point. A full loop that starts and ends at the same point is probably easiest to add into a cable run. Something you do see in many electrical installations is drip loops that include a couple of metres of spare cable looped multiple times.

You also see loose cables hanging from a cabinet with no attempt at cable management – any loops should be held in place, not flapping around in the wind placing stress on terminations.