Which wire or wires in a four-conductor 240 VAC circuit should be attached to fuses or circuit breakers?
The correct answer is A: Only the hot wires. The wire or wires in a four-conductor 240 VAC circuit that should be attached to fuses or circuit breakers are only the hot wires. Hot wires (ungrounded conductors) must be protected by fuses or breakers; neutral and ground should not be fused. For amateur radio operators, this is critical electrical safety. Understanding this helps ensure safe electrical installation.
Exam Tip
240V circuit fusing = only hot wires. Think 'H'ot 'W'ires = 'H'ave 'W'ires fused. Hot wires (ungrounded conductors) must be protected by fuses or breakers; neutral and ground should not be fused. Not neutral, not ground, not all - just hot wires.
Memory Aid
"240V circuit fusing = only hot wires. Think 'H'ot 'W'ires = 'H'ave 'W'ires fused. Hot wires (ungrounded conductors) must be protected by fuses or breakers; neutral and ground should not be fused. Critical electrical safety."
Real-World Application
A four-conductor 240 VAC circuit: Two hot wires (L1 and L2), neutral, and ground. Only the hot wires should be attached to fuses or circuit breakers. Neutral and ground should never be fused - they must remain continuous. This is critical electrical safety - only hot wires are protected by fuses or breakers.
National Electrical CodeKey Concepts
Why Other Options Are Wrong
Option B: Incorrect. Neutral wire shouldn't be fused - only hot wires should be fused. Neutral is grounded and shouldn't be interrupted. Neutral is wrong.
Option C: Incorrect. Ground wire shouldn't be fused - ground should never be interrupted. Ground is wrong.
Option D: Incorrect. All wires shouldn't be fused - only hot wires should be fused. All wires is wrong.
题目解析
The correct answer is A: Only the hot wires. The wire or wires in a four-conductor 240 VAC circuit that should be attached to fuses or circuit breakers are only the hot wires. Hot wires (ungrounded conductors) must be protected by fuses or breakers; neutral and ground should not be fused. For amateur radio operators, this is critical electrical safety. Understanding this helps ensure safe electrical installation.
考试技巧
240V circuit fusing = only hot wires. Think 'H'ot 'W'ires = 'H'ave 'W'ires fused. Hot wires (ungrounded conductors) must be protected by fuses or breakers; neutral and ground should not be fused. Not neutral, not ground, not all - just hot wires.
记忆口诀
240V circuit fusing = only hot wires. Think 'H'ot 'W'ires = 'H'ave 'W'ires fused. Hot wires (ungrounded conductors) must be protected by fuses or breakers; neutral and ground should not be fused. Critical electrical safety.
实际应用示例
A four-conductor 240 VAC circuit: Two hot wires (L1 and L2), neutral, and ground. Only the hot wires should be attached to fuses or circuit breakers. Neutral and ground should never be fused - they must remain continuous. This is critical electrical safety - only hot wires are protected by fuses or breakers.
错误选项分析
Option B: Incorrect. Neutral wire shouldn't be fused - only hot wires should be fused. Neutral is grounded and shouldn't be interrupted. Neutral is wrong. Option C: Incorrect. Ground wire shouldn't be fused - ground should never be interrupted. Ground is wrong. Option D: Incorrect. All wires shouldn't be fused - only hot wires should be fused. All wires is wrong.
知识点
240 VAC circuit, Four-conductor, Hot wires, Fuses or circuit breakers
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.