*Question G0B01:
Which wire or wires in a four-conductor 240 VAC circuit should be attached to fuses or circuit breakers?*  

*Correct Answer is  A: Only the hot wires*  

### AI Response: (may contain errors)  

In a four-conductor 240 VAC circuit, the correct practice is to attach fuses or circuit breakers only to the hot wires. Here's why:

1. **Correct Answer: Only the hot wires (Choice A)**
   - **Reason**: The purpose of fuses and circuit breakers is to interrupt the flow of electricity in the event of an overload or short circuit. In a 240 VAC circuit, the hot wires carry the voltage potential. By placing fuses or circuit breakers on these wires, you ensure that the circuit is safely interrupted if there is an excessive current flow, preventing potential hazards like fires or equipment damage.

2. **Why the Other Choices are Incorrect:**
   - **Choice B: Only the neutral wire**
     - The neutral wire is intended to carry current back to the source and is typically at ground potential. Fusing the neutral wire would not effectively interrupt the circuit in the event of a fault, as the hot wires would still be live.
   - **Choice C: Only the ground wire**
     - The ground wire is a safety path for fault currents and is not part of the normal current-carrying conductors. It should never be fused, as it needs to remain intact to safely carry fault currents away from equipment.
   - **Choice D: All wires**
     - Fusing all wires, including neutral and ground, is unnecessary and could create safety issues. The neutral and ground wires should remain unfused to ensure proper operation and safety.

**Rule of Thumb:**
- Always fuse or break the hot wires in an AC circuit to ensure that the circuit can be safely interrupted in case of a fault. This is a fundamental safety practice in electrical systems.