What is UL 487 ?

What is UL 489?

UL 489 is a standard published by Underwriters Laboratories (UL) that establishes the performance and safety requirements for molded-case circuit breakers (MCCBs). The acronym "UL" stands for Underwriters Laboratories, a renowned global safety certification organization.

MCCBs are widely used in various electrical systems to protect them from overloads, short circuits, and other electrical faults. Understanding UL 489 and its requirements is crucial for ensuring the safety and reliability of electrical installations.

The Purpose of UL 489

The primary purpose of UL 489 is to establish the performance and safety requirements for MCCBs. These circuit breakers play a vital role in preventing electrical fires, minimizing damage to equipment, and keeping people safe. UL 489 certification ensures that MCCBs meet specific tests and criteria related to their ability to interrupt fault currents, withstand environmental conditions, and exhibit proper electrical insulation.

Compliance with this standard guarantees that MCCBs have undergone rigorous testing, adhering to industry best practices.

Key Requirements of UL 489

UL 489 provides guidelines and requirements for safety standards of MCCBs, including current ratings, interrupting capacities, and endurance tests. The standard defines various performance and construction aspects such as the ability to interrupt fault currents, withstand environmental conditions, and maintain proper electrical insulation.

To achieve UL 489 certification, MCCBs must comply with specific requirements outlined in the standard. These requirements include but are not limited to:

Electrical continuity: MCCBs must be able to conduct electrical currents without a fault.

Overcurrent protection: MCCBs must be able to interrupt fault currents in a timely manner.

Heat resistance: MCCBs must be able to withstand high temperatures without suffering damage.

Electrical insulation: MCCBs must have proper electrical insulation to prevent electrical hazards.

Operating temperature: MCCBs must be able to operate within their specified temperature range without suffering damage.

Key Features of UL 489

UL 489 is a widely recognized standard in the electrical industry that provides guidelines for the design, manufacture, and testing of MCCBs. The standard is essential for ensuring the safety and reliability of electrical installations that use these devices.

By adhering to the requirements outlined in UL 489, manufacturers can ensure that their MCCBs are safe, reliable, and meet industry best practices. Compliance with the standard is critical for protecting people and equipment from electrical hazards.