Which type of terminal is considered unsatisfactory for general electrical systems?

Soldered terminals are often considered unsatisfactory for general electrical systems due to several inherent limitations associated with soldering. While soldered connections can provide good conductivity and are quite strong when done correctly, they are not as reliable in environments where thermal expansion, vibrations, and mechanical stress are factors. Over time, solder joints can become brittle and may fail, particularly if exposed to fluctuating temperatures or vibrations that are common in an aircraft environment. This can lead to poor connectivity and compromise overall system performance.

In contrast, other types of terminals, such as crimped terminals, provide robust connections that can better withstand environmental stressors. Plug-in terminals allow for easy disconnection and reconnection, which can facilitate maintenance. Screwed terminals offer good mechanical strength and reliability in high-vibration environments. For these reasons, soldered terminals are often not preferred for applications requiring high reliability in electrical systems, such as in aviation where operational safety is paramount.