What is UL 877 ?

Title: Unlocking the Benefits of UL 877 and UL 878: The Safety Standards for Electrical and Industrial Metallic Tubing

The world we live in today is increasingly reliant on electricity. As we rely on more and more electronic devices, the safety of our electrical infrastructure becomes increasingly important. This is where the Underwriters Laboratories (UL) comes in. UL is a global safety certification organization that establishes and enforces safety standards for a wide range of products, including electrical and metallic tubing. In this article, we will explore the purpose and requirements of UL 877 and UL 878, two of UL's critical safety standards for electrical and industrial metallic tubing.

Understanding UL 877 and UL 878

UL 877, also known as "Standard for Electrical Metallic Tubing," is a set of safety standards that regulates the installation and use of electrical metallic tubing (EMT) in commercial and industrial settings. The main purpose of UL 877 is to ensure the safety and reliability of electrical systems that incorporate EMT for conduit installations.

UL 877 provides guidelines for manufacturers, electricians, and inspectors to follow when using EMT for conduit installations. By adhering to UL 877 requirements, professionals can mitigate potential electrical hazards, reduce the risk of fire, and enhance the overall safety of electrical infrastructure.

The purpose of UL 878 is to assess the safety and performance characteristics of industrial control equipment (ICE). ICE refers to devices used in manufacturing processes, such as programmable logic controllers (PLCs), motor starters, variable frequency drives (VFDs), and power supplies. These devices play a critical role in ensuring smooth and efficient operation of industrial machinery.

UL 878 is a vital standard that ensures the safety and reliability of electrical devices used in critical control systems.

Requirements of UL 877

UL 877 provides a comprehensive set of requirements for manufacturers, installers, and inspectors to follow when using EMT for conduit installations. The standard covers various aspects, including:

Electrical Characteristics: The standard defines the electrical characteristics of EMT, including resistance, voltage, and current.

Conduit Design: The standard outlines the dimensions and specifications of EMT conduits, as well as the materials used in their construction.

Installation: The standard provides guidelines for installing EMT, including the recommended installation location, the number of phases, and the required clearances.

Inspection: The standard specifies the procedures for inspecting EMT installations, including visual inspections, functional tests, and stress tests.

Marking: The standard requires manufacturers to mark their EMT products with the appropriate UL 877 identification number.

Testing: The standard outlines the testing requirements for EMT, including the testing procedures for various types of EMT products.

Conclusion

UL 877 and UL 878 are two critical safety standards for electrical and industrial metallic tubing. By adhering to these standards, manufacturers, installers, and inspectors can ensure the safety and reliability of electrical devices used in critical control systems. Understanding the requirements of UL 877 and UL 878 is crucial for both consumers and manufacturers. By following these standards, we can reduce the risk of electrical hazards, prevent fires, and enhance the overall safety of our electrical infrastructure.