What must be the relationship between the inside diameter of a conduit and the outside diameter of a wire bundle?

The correct answer indicates that the inside diameter of the conduit must be 25% larger than the outside diameter of the wire bundle. This relationship is essential for ensuring that there is adequate space within the conduit for the wire bundle.

A conduit that is sized appropriately allows for easy installation and removal of the wire bundles without causing damage or excessive bending. It also provides sufficient air circulation around the wires, which is vital for heat dissipation. Having a conduit that is sized too closely to the wire bundle may lead to mechanical stresses on the wires and can potentially hinder the installation process.

In aircraft maintenance and electrical installations, adhering to these spacing and sizing guidelines is mandated to promote safety and functionality. Proper conduit sizing contributes to reducing the risk of wire overheating and electrical failures that could arise from poor installations.

Therefore, the 25% increase in size ensures that all considerations regarding safety, ease of installation, and maintenance are met effectively.