What type of screws or fastening devices must be used to secure removable covers of conduit boxes according to standard UL 68(1)?

The requirement to use one-way screws to secure removable covers of conduit boxes is based on safety and tamper-resistance considerations. One-way screws are designed to be easily installed but more challenging to remove, providing a level of security that is beneficial in preventing unauthorized access. This type of fastening mechanism ensures that covers are securely fastened, thus protecting the internal electrical components from accidental contact and tampering.

In contrast, other types of fastening devices do not offer the same level of security. Standard screws and multi-way screws can typically be removed easily with common tools, which may compromise the safety and security intended for these installations. Utilizing one-way screws aligns with best practices for ensuring that electrical enclosures remain secure while allowing authorized personnel to access them when necessary.