What replaced UL508?

In the world of electrical safety standards, UL 508 has long been a familiar name. It has been the go-to standard for industrial control equipment in North America for decades. However, as technology evolves and new challenges emerge, UL 508 has been replaced by a more comprehensive and up-to-date standard - UL 60947.

A Brief of UL 508

UL 508, officially known as the "Standard for Industrial Control Equipment," was first published by Underwriters Laboratories in 1959. It provided guidelines and requirements for the electrical safety of various control equipment used in industrial settings, such as motor controllers, switchgear, and industrial control panels.

Over the years, UL 508 underwent several revisions to keep up with technological advancements and changing industry needs. However, it started showing limitations in addressing emerging concerns related to product safety and performance. This prompted the development of a new standard that could better cater to the evolving needs of the industry.

The Rise of UL 60947

UL 60947, also known as the "Standard for Low-Voltage Switchgear and Controlgear," emerged as the successor to UL 508. Published by Underwriters Laboratories in 1997, this revised standard incorporates significant updates and enhancements to address the shifting landscape of industrial control equipment.

UL 60947 not only builds upon the foundation laid by UL 508 but also takes into account various global standards and regulations. It harmonizes with IEC (International Electrotechnical Commission) standards, enabling its adoption and acceptance on an international scale beyond North America. This alignment with global standards sets UL 60947 as the benchmark for compliance for control equipment manufacturers and users worldwide.

Main Differences Between UL 508 and UL 60947

While UL 508 emphasized product safety, UL 60947 encompasses a broader scope that includes both safety and performance requirements. It introduces updated tests, ratings, and construction standards to ensure that control equipment not only operates safely but also performs reliably in various conditions.

One of the significant changes in UL 60947 is the classification of control equipment into three types: Type A, Type B, and Type C. This classification accounts for different usage scenarios, such as motor circuits, branch circuits, and control circuits, and provides specific requirements accordingly.

Furthermore, UL 60947 incorporates newer technologies and addresses emerging concerns related to energy efficiency, arc flash hazards, and environmental factors. Manufacturers and end-users need to familiarize themselves with these updates and implement appropriate measures to meet the requirements specified in the new standard.

In conclusion, UL 60947 has replaced UL 508 as the primary standard for industrial control equipment. Its comprehensive approach ensures both safety and performance, aligning it with global standards and addressing evolving industry needs. Manufacturers and users should transition to UL 60947 to ensure compliance and stay ahead in the ever-changing landscape of electrical safety standards.