Which drawings satisfy the NEC® requirements for conductor length in boxes?

In the context of the National Electrical Code (NEC) requirements for conductor length in junction boxes, the determination relies on how well each drawing illustrates the necessary clearances and allowances for conductors. Specifically, the NEC has guidelines to ensure that conductors in a junction box can have sufficient length to allow for proper installation, manipulation, and connection without risk of damage or excessive stress.

When assessing the drawings, Drawing I meets the NEC requirement by clearly depicting conductors that are adequately long to be safely maneuvered and connected within the box without straining the wires. This allows for secure and reliable electrical connections, which are crucial for safety and functionality in electrical installations.

In contrast, other drawings may not fully adhere to the specifications laid out by the NEC, either by showing conductors that are too short or neglecting to illustrate the necessary space and length requirements for safe handling and terminations. It's critical to reference the NEC standards regarding minimum lengths and the implications of inadequate wire lengths in junction boxes to achieve a secure and compliant installation.

Thus, Drawing I is the only one that符合了 NEC 对于导体在盒子中的长度要求, ensuring that the installation is safe and adheres to established electrical codes.