What is the preferred placement for all downleads on a structure?

The preferred placement for all downleads on a structure being on one side or one end only is based on the principles of efficient lightning protection systems. This configuration helps to minimize the impedance and ensures that the lightning current can be safely conducted down to the earth without creating excessive magnetic fields or potential differences that might lead to side-flashes or equipment damage.

Having downleads concentrated on one side allows for better control of the lightning path, reducing the likelihood of unwanted currents affecting other parts of the structure or the surrounding area. It also simplifies the grounding system as there are fewer paths for the currents to take, minimizing the risk of lightning-induced damage.

In contrast, spreading downleads on opposite sides or having them in a random pattern could lead to a greater risk of current divergence where it may not be effectively directed to the ground. Placing downleads on every corner introduces unnecessary complexity and could result in varied coupling effects, ultimately compromising the system's effectiveness. Thus, concentrating downleads on one side ensures a more efficient and safe lightning protection strategy.