Final answer:
Three wires under a terminal require a three-wire connector for safe and secure electrical connections. The standard three-wire system in outlets provides improved safety through proper color-coded insulation and grounding, reducing the risk of electrical shock.
Step-by-step explanation:
When connecting wires under a terminal, doubled wires must indeed use a two-wire connector, and for three wires, the appropriate answer would be to require a three-wire connector. This is because correct and safe electrical practices dictate that the number of conductors being connected should match the connector's design to ensure secure and reliable electrical connections, as per the National Electrical Code (NEC) standards.
In the context of a three-hole outlet and a three-wire system, the importance of proper wire connection and insulation is critical. This system includes a live/hot wire, a neutral wire, and an earth/ground wire, which is often indicated by green color coding but can vary, such as being yellow or just bare wire. Striped coatings may also be used for improved visibility and to assist those who are colorblind. Proper insulation and connection are vital for the safety and functionality of electrical devices, especially in environments where the risk of electrical shock is heightened, such as near water in a kitchen setting.