What is UL 489 Ed.12?

UL 489 Ed.12 is a technical specification that sets the standard for molded-case circuit breakers and circuit breaker disconnect switches. It is an important guideline in electrical engineering, ensuring the safety and reliability of electrical systems.

The Purpose of UL 489 Ed.12

The primary purpose of UL 489 Ed.12 is to provide requirements for the design, testing, and performance of molded-case circuit breakers and circuit breaker disconnect switches. These devices are crucial components in electrical distribution systems, safeguarding against overloads, short circuits, and other electrical faults.

By following the specifications outlined in UL 489 Ed.12, manufacturers can produce circuit breakers that meet the necessary safety standards. This helps to ensure the protection of equipment and personnel from electrical hazards.

Key Requirements of UL 489 Ed.12

UL 489 Ed.12 outlines various key requirements that circuit breakers must fulfill to comply with safety standards. Some of these requirements include:

Interrupting Capacity: Circuit breakers must be able to safely interrupt the flow of current under both normal and fault conditions.

Temperature Rise: The temperature rise of circuit breakers should remain within acceptable limits during operation.

Short-Circuit Withstand Rating: Circuit breakers need to withstand and interrupt high fault currents without any damage or malfunction.

Endurance: Circuit breakers should have a sufficient lifespan and be able to handle multiple operations over time.

These requirements assure that circuit breakers perform effectively and reliably in various scenarios, preventing electrical accidents and minimizing downtime.

Compliance and Certification

Manufacturers of circuit breakers must undergo rigorous testing and evaluation processes to determine compliance with UL 489 Ed.12. Once their products meet the requirements, they can receive certification from recognized bodies like Underwriters Laboratories (UL).

It is important for buyers and installers of electrical equipment to look for circuit breakers that are certified to UL 489 Ed.12. This ensures they are investing in high-quality products that meet established safety standards, reducing the risk of potential electrical hazards.

In conclusion, UL 489 Ed.12 sets the standard for molded-case circuit breakers and circuit breaker disconnect switches. It provides guidelines and requirements to ensure the safety and reliability of these devices in electrical distribution systems. Manufacturers need to comply with the technical specifications outlined in UL 489 Ed.12 to produce circuit breakers that meet safety standards. Buyers and installers should seek certified products to ensure they are investing in reliable and safe electrical equipment.