What is the purpose of enclosing wires or electrical units in metal?

Enclosing wires or electrical units in metal primarily serves to eliminate interference with radio reception. This is a critical function because metal enclosures act as Faraday cages, which prevent external electromagnetic interference from affecting the signals being transmitted or received. By shielding sensitive electronic components from outside noise, metal enclosures protect the integrity of the signals, ensuring clearer communication and more reliable operation of avionics systems.

While enhancing insulation, promoting cooling, or increasing conductivity are important considerations in electrical design, these functions do not address the specific purpose of using metal enclosures for wires or units in terms of radio communication. The focus on shielding from interference makes the choice of enclosing electrical components in metal particularly beneficial for maintaining the effectiveness of radio equipment within an aircraft.