What is UL 971 Ed. 2?

UL 971 Ed. 2 is a technical standard developed by Underwriters Laboratories (UL) to ensure the safety and performance of electrical systems in hazardous locations. This standard specifically addresses underground storage tank applications, covering electrical equipment and wiring used in environments where flammable liquids or gases are present.

Scope and Purpose of UL 971 Ed. 2

The primary focus of UL 971 Ed. 2 is to establish requirements for the construction, design, installation, and operation of electrical systems in underground storage tank applications. These systems include all electrical components such as control panels, power distribution units, conductors, and lighting fixtures. The standard aims to prevent fires and explosions by ensuring that these systems meet stringent safety criteria and can withstand potentially hazardous conditions.

Key Requirements of UL 971 Ed. 2

UL 971 Ed. 2 sets forth specific requirements that electrical systems in underground storage tank applications must meet. These requirements cover various aspects, including:

Electrical equipment must be designed and constructed to withstand exposure to flammable vapors and corrosive substances commonly found in underground storage tank environments.

Wiring methods and materials must be selected and installed with consideration for the potential presence of flammable liquids or gases.

Grounding and bonding techniques must be employed to minimize the risk of electric shock and reduce the possibility of ignition from static charges.

Systems must be adequately sealed and protected to prevent the ingress of moisture, dust, or other contaminants.

Emergency shutdown controls and alarms should be provided to allow immediate response to any hazardous condition.

Compliance and Certification

To demonstrate compliance with UL 971 Ed. 2, electrical equipment manufacturers and installers are required to undergo rigorous testing and evaluation processes. Once the equipment meets all the necessary criteria, it can be certified by UL. This certification ensures that the equipment has been found to meet the safety standards outlined in UL 971 Ed. 2 and provides assurance to consumers and regulatory bodies that the product is reliable and safe for its intended use.

The Importance of UL 971 Ed. 2

UL 971 Ed. 2 plays a vital role in promoting the safety of electrical systems in underground storage tank applications. By adhering to this standard, the risk of fire, explosions, and other hazardous incidents caused by electrical faults can be significantly reduced. Furthermore, compliance with UL 971 Ed. 2 helps protect both people and property, ensuring the smooth operation of underground storage tank facilities while minimizing risks to workers, surrounding communities, and the environment.

Conclusion

UL 971 Ed. 2 sets forth a comprehensive framework for the design, installation, and operation of electrical systems in underground storage tank applications. Compliance with this standard is crucial to minimize the potential risks associated with flammable liquids or gases. By following the requirements outlined in UL 971 Ed. 2 and obtaining the proper certifications, manufacturers and installers can ensure the safety and reliability of their electrical equipment in these challenging environments.