What is UL366?

UL366 is a professional technical standard that defines the requirements for electrical nonmetallic tubing (ENT) used in buildings. ENT, also known as smurf tube or blue tube due to its typical color, is a flexible corrugated plastic conduit designed for protecting and routing electrical wires in residential and commercial structures. UL366 sets specific criteria for the manufacturing, installation, and performance of ENT, ensuring its safety and reliability.

Manufacturing Requirements

To comply with UL366, ENT manufacturers must meet rigorous standards during the production process. The tubing must be constructed from fire-resistant materials, allowing it to reduce the spread of flames in case of a fire. Additionally, it must have sufficient tensile strength to withstand normal installation procedures without breaking or deforming. The manufacturing process should also ensure that the ENT is resistant to corrosion, moisture, and UV radiation, making it suitable for both indoor and outdoor applications.

Installation Guidelines

Proper installation of ENT is crucial to its effectiveness and conforming to UL366. When installing the tubing, it should be free from any damage or defects. Any cuts or punctures can compromise its ability to protect electrical wiring. It is important to eliminate any sharp edges or rough surfaces where the ENT passes through walls or ceilings. Sharp edges can potentially damage the insulation of wires over time, leading to electrical hazards. Following proper bending radius guidelines is also essential to prevent kinking or collapsing of the tubing.

Performance Standards

UL366 outlines various performance standards that ENT must meet. These include flame resistance, smoke generation, and durability under different environmental conditions. The tubing should be able to withstand extreme temperatures without melting or releasing toxic fumes. It should not contribute significantly to the spread of smoke in the event of a fire. ENT must also exhibit strength and resilience when subjected to physical stress or impact, ensuring it can endure typical construction processes and withstand accidental damage.