The UL standard used to evaluate receptacles (or outlets) is UL 498, which is titled "Attachment Plugs and Receptacles". This standard covers attachment plugs, receptacles, and similar wiring devices intended for use in branch circuits in accordance with the National Electrical Code (NEC).
UL 498 sets out requirements for the construction and performance of receptacles, including their electrical and mechanical properties. The standard includes tests for durability, aging, and environmental conditions such as temperature and humidity. It also covers the safety features of receptacles, such as resistance to heat, fire, and impact, as well as the prevention of electrical shock hazards.
In order to be UL listed, a receptacle must undergo testing and meet the requirements outlined in UL 498. The UL listing mark on a receptacle indicates that it has been independently tested and certified to meet the safety standards and requirements of UL 498.
In addition to the basic requirements, UL 498 also specifies additional tests and requirements for specific types of receptacles, including ground-fault circuit interrupter (GFCI) receptacles and tamper-resistant (TR) receptacles.
For GFCI receptacles, UL 498 requires additional tests to verify that the device can detect and interrupt a ground fault. The test involves applying a fault current from the hot, neutral, and ground conductors to simulate a fault to ground. The GFCI must trip and cut off Additionally, UL 498 includes requirements for markings and instructions that must be provided with receptacles. This includes information such as electrical ratings, grounding requirements, and installation instructions. The standard also covers the use of GFCI (ground fault circuit interrupter) and AFCI (arc fault circuit interrupter) protection in receptacles to provide additional protection against electrical hazards.
Receptacles are an essential component of electrical systems and are used in a wide range of applications, from residential to commercial and industrial settings. The UL 498 standard helps to ensure that receptacles are safe, reliable, and compatible with the electrical codes and regulations in place.
It is important to note that UL 498 is a standard for North America. Other regions, such as Europe and Asia, have their own standards for receptacles, such as the IEC 60884 standard in Europe. However, these standards share similar requirements for the safety and performance of receptacles.
UL 498 is regularly updated to incorporate new technologies and advances in electrical safety. As the electrical industry advances, the standard continues to evolve to ensure the safety and reliability of receptacles. For example, in recent years, the standard has been updated to address emerging technologies such as USB charging ports integrated into receptacles.
In addition to testing and certification for UL listing, UL 498 also includes a follow-up service program to ensure that listed receptacles continue to meet the standard's requirements. The follow-up service program includes periodic testing and inspections of listed products to verify ongoing compliance with the standard.
UL 498 plays an important role in ensuring the safety and performance of receptacles used in electrical systems. When selecting and installing receptacles, it is important to look for products that have been certified to meet the requirements of UL 498 and other relevant safety standards. This helps to ensure that the receptacles are safe, reliable, and compatible with the necessary electrical codes and regulations.