Final answer:
In a two wire relay system using a switch with a pilot light, the switch must have three connections, while the relay will have at least four terminals. The switch connections include the hot wire, the load to the relay, and the pilot light circuit. The three-wire system with hot, neutral, and ground wires, together with GFCIs, is essential for safety in electrical systems.
Step-by-step explanation:
If a switch with a pilot light is used in a two wire relay system, the switch must have three connections: one for the incoming hot wire, one connection serving as the outgoing load to the relay, and a third one to power the pilot light when the switch is on. Often, the switch will share the neutral wire to complete the circuit for the pilot light. The relay itself will typically have a minimum of four terminals: two for the control circuit and two for the switched circuit. If the pilot light is to be controlled by the relay, this configuration may be different, but at a minimum, the relay will need two wires for operation, one being the control wire and the other being the neutral.
A three-wire system includes live/hot, neutral, and ground wires, which helps prevent both shock and thermal hazards. When a ground fault circuit interrupter (GFCI) is in use, it prevents electrical shock by detecting any unintended current paths. This vital safety feature is part of modern electrical code and design.