Oklahoma Electrical Practice Exam

Unless specifically listed otherwise, what is the maximum spacing between supports for 4-inch rigid non-metallic conduit?

1. 5 feet

2. 6 feet

3. 7 feet

4. 8 feet

The correct answer is: 7 feet

The maximum spacing between supports for a 4-inch rigid non-metallic conduit is typically determined by the National Electrical Code (NEC) requirements, which are designed to ensure the safety and integrity of electrical installations. Based on the NEC standards, the correct spacing for supports for this type of conduit is indeed up to 10 feet, but manufacturers may have specific instructions that modify this general requirement. When narrowing down the maximum spacing, the answer identifies that, unless stated otherwise, 7 feet is considered a reasonable limit that aligns with best practices for maintaining support and adherence to the physical properties of the conduit. This spacing helps prevent sagging and potential damage to the conduit, ensuring it remains securely fastened and mitigates risks associated with environmental factors. In practical applications, spacing is determined by the conditions of installation, including the weight and type of the materials being carried in the conduit, as well as environmental factors that could impact its performance. Adhering to this recommendation is crucial for ensuring electrical systems perform safely and effectively over time.