Understanding the Shunt Trip and Auxiliary Functions of MCCB

Molded Case Circuit Breakers (MCCBs) serve as critical components in modern electrical protection systems, offering both primary circuit protection and advanced control capabilities. Among their most valuable features are shunt trip mechanisms and auxiliary functions, which significantly enhance operational flexibility and safety. YUYE Electric Co., Ltd., a leading innovator in electrical protection devices, has developed a comprehensive range of MCCBs with sophisticated shunt trip and auxiliary functionalities designed to meet the demanding requirements of industrial and commercial applications.

Shunt Trip Functionality: Principle and Applications
The shunt trip represents an essential remote tripping mechanism in MCCBs. YUYE Electric’s shunt trip units operate on a simple yet effective principle: when a control voltage (typically 24V, 48V, 110V, or 220V AC/DC) is applied to the shunt trip coil, it generates sufficient electromagnetic force to mechanically trip the breaker, regardless of the actual circuit conditions.

Key applications include:

Emergency shutdown systems in industrial plants

Fire protection circuits where immediate power cutoff is required

Remote operation in hard-to-access installations

Integration with building management systems

YUYE Electric’s shunt trip modules feature:

Wide voltage compatibility (12-440V AC/DC)

Fast response time (<20ms)

High mechanical endurance (>10,000 operations)

Compact design for space-constrained installations

Auxiliary Contact Functions: Monitoring and Control
Auxiliary contacts in YUYE MCCBs serve as vital status indicators and control elements. These normally open (NO) and normally closed (NC) contacts mirror the main contact position, providing crucial information for system monitoring and interlocking.

Primary functions include:

Breaker status indication (ON/OFF/TRIP)

Remote monitoring through SCADA systems

Interlocking with other protective devices

Alarm signaling for fault conditions

YUYE’s auxiliary contact blocks offer:

High electrical endurance (>100,000 operations)

Silver alloy contacts for reliable switching

Modular design for easy retrofitting

IP65 protection grade for harsh environments

Undervoltage Release (UVR) Function
YUYE’s MCCBs incorporate advanced UVR mechanisms that automatically trip the breaker when voltage drops below a preset threshold (typically 35-70% of nominal voltage). This critical function:

Protects motors from damage during brownouts

Prevents equipment operation under unsafe voltage conditions

Ensures proper sequence control in automated systems

Combined Functionality for Enhanced Protection
YUYE Electric’s engineering expertise shines in integrated solutions combining multiple functions:

Shunt trip + auxiliary contacts for comprehensive remote control

UVR + alarm contacts for complete voltage monitoring

Custom configurations for specialized applications

Technical Specifications and Certifications
All YUYE MCCB accessories comply with:

IEC 60947-2 standards

UL 489 requirements

CE marking for European markets

RoHS compliance for environmental safety

Installation and Maintenance Considerations
Proper implementation requires:

Correct voltage matching for shunt trip coils

Appropriate contact ratings for auxiliary circuits

Regular functional testing (recommended annually)

Environmental protection for outdoor installations

Case Study: Industrial Application
In a recent automotive manufacturing plant project, YUYE’s MCCBs with shunt trip and auxiliary functions were implemented to:

Enable emergency stops from multiple control points

Provide real-time status feedback to the central control room

Integrate with the fire alarm system for automatic shutdown
The solution reduced downtime by 35% and improved safety compliance.

In the end
The shunt trip and auxiliary functions in YUYE Electric’s MCCBs represent sophisticated solutions for modern electrical protection needs. By combining reliable remote operation capabilities with comprehensive status monitoring, these features significantly enhance system safety, control flexibility, and operational efficiency. YUYE Electric continues to lead in innovation, offering robust, certified solutions for diverse application requirements across industries.

For technical specifications or application support, please contact YUYE Electric’s engineering team or visit our official website for detailed product information.