UL 508 A Literature

A White Paper on UL 508A, NEC 409 and related codes and standards changes that affect panel builders, machine builders and those who design and develop industrial control panels.

Understanding the impact of NEC® Article 409 and UL 508A

Applying Powerpact® H- and J- frame Molded Case Circuit Breakers in UL Type Control Panels

Powerpact® H- and J- Frame molded case circuit breakers provide a convenient and versatile solution for the demanding needs of control panel customers. These circuit breakers are designed to provide a comprehensive product solution by delivering high interruption ratings, many terminal options, wide variety of actuators, and field installable accessories.

The National Electrical Code (NEC) is primarily concerned with preventing fires, not damage to electrical apparatuses. NEC’s interest in the SCCR is the amount of momentary electrical current that a device can withstand before it will produce an uncontainable fire and/or explosion. If the fault current is less than the equipment’s SCCR, then the equipment should mitigate, the preceding hazards.

This data bulletin describes UL combination starter types, the implications of the UL "self-protected" designation, coordination of motor control equipment, and the benefits of Type E and Type F combination starters in panel design.