Are there restrictions on the use of flexible conduits for service?

Flexible conduits have specific restrictions and regulations outlined in the National Electrical Code (NEC), particularly in Article 230, which covers services. While flexible conduits offer versatility and ease of installation in certain scenarios, their use is not unrestricted. The NEC specifies that flexible conduits, such as those classified as flexible metal conduits (FMC) or non-metallic flexible conduits (NFMC), must meet particular requirements in relation to grounding, weatherproofing, and other installation conditions to ensure safety and reliability.

For instance, while flexible conduits can be advantageous in applications where movement or vibration occurs, they are not generally suitable for outdoor service entrance applications unless they meet specific conditions that ensure they are appropriately rated for environmental factors. Therefore, using flexible conduits must align with relevant NEC standards, which dictate where and how they can be employed effectively and safely. This adherence to specific applications is crucial for maintaining compliance and ensuring the overall safety and functionality of the electrical system.