What is UL 917

UL 917 is a standard developed by Underwriters Laboratories (UL) to ensure the safety and performance of electrical devices in hazardous locations. This standard applies to industrial control panels, relays, and similar equipment that are intended for use in environments where the presence of flammable gases, vapors, or combustible dusts could create a potential fire or explosion hazard. In this article, we will explore the key requirements and features of UL 917.

Scope and Application

The scope of UL 917 covers industrial control panels rated up to 600 volts and intended for use in hazardous locations as classified by the National Electrical Code (NEC). It specifies the minimum safety requirements for the design, construction, and performance of these panels to minimize the risk of fire or explosion caused by electrical faults or abnormal conditions.

Key Requirements of UL 917

One of the crucial requirements of UL 917 is the use of approved components and materials that can withstand the harsh environment of hazardous locations. These materials should be resistant to corrosion, high temperatures, and exposure to flammable substances. Additionally, the standard mandates proper grounding and bonding techniques to prevent the buildup of static charges and minimize the risk of ignition.

Another important aspect of UL 917 is the verification of the panels' suitability for the intended hazardous location through rigorous testing and evaluation. The panels must undergo various tests, including dielectric voltage-withstand, insulation resistance, and temperature-rise tests, to ensure their reliability and safety under normal and fault conditions.

Benefits of UL 917 Compliance

Compliance with UL 917 offers several benefits for manufacturers and end-users. Firstly, it ensures the safety and reliability of industrial control panels in hazardous environments, minimizing the risk of fire, explosions, and personnel injuries. Secondly, UL compliance enhances the reputation of manufacturers by demonstrating their commitment to producing high-quality and safe products.

For end-users, UL 917-compliant panels provide peace of mind that they are using equipment that meets the highest safety standards. This reduces potential liability and ensures a safer working environment for employees. Additionally, compliance with UL standards may be required by regulatory bodies or insurance companies, making it essential for manufacturers to comply with these standards to enter certain markets or obtain necessary certifications.