*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 answer is that only the hot wires should be attached to fuses or circuit breakers. Here's why:

### Explanation of the Correct Answer (A: Only the hot wires)
- **Hot Wires**: In a 240 VAC circuit, there are typically two hot wires (often referred to as L1 and L2) that carry the voltage. These wires are the ones that need protection from overloads and short circuits, which is why they should be connected to fuses or circuit breakers. If a fault occurs, the circuit breaker will trip, cutting off power to prevent damage or fire.

### Explanation of Incorrect Choices
- **B: Only the neutral wire**: 
  - The neutral wire is not connected to fuses or circuit breakers in a 240 VAC circuit because it is not carrying the load voltage. The neutral is typically grounded and serves as a return path for current in 120 VAC circuits, but in a 240 VAC setup, it is not used in the same way.

- **C: Only the ground wire**: 
  - The ground wire is a safety feature designed to protect against electrical shock and does not carry current under normal operation. It is not connected to fuses or circuit breakers because it is not intended to interrupt power flow.

- **D: All wires**: 
  - This option is incorrect because connecting all wires (including neutral and ground) to fuses or circuit breakers would not provide effective protection and could create safety hazards. Only the hot wires should be protected.

### Summary
- **Hot wires** are the only conductors that should be connected to fuses or circuit breakers in a 240 VAC circuit to ensure proper protection against overloads and faults. The neutral and ground wires serve different purposes and do not require circuit protection in this context. 

This understanding is crucial for safe electrical practices and is a key concept for the Extra Class exam.