Siemens 3VA1120-5EE32-0AA0 3VA11 Series Air Circuit Breaker 20A 3P 55kA
The Siemens 3VA1120-5EE32-0AA0 is a robust 3-pole, 20A, 3-phase air circuit breaker from the 3VA11 series, engineered for exceptional protection with a breaking capacity of 55kA. This breaker excels in safeguarding electrical installations against overcurrents and short circuits, offering reliable performance in demanding industrial environments. Its advanced thermal-
Product Specifications
| Feature | Specification |
| :--------------------------- | :-------------------------------------------- |
| Product Type | Air Circuit Breaker |
| Series | 3VA11 |
| Model Number | 3VA1120-5EE32-0AA0 |
| Rated Current (In) | 20 A |
| Number of Poles | 3P (3-pole) |
| Breaking Capacity (Icu/Ics) | 55 kA |
| Rated Voltage (Ue) | Up to 690 V AC |
| Release Type | Thermal-magnetic |
| Trip Unit | LSI (Long-time, Short-time, Instantaneous) |
| Mounting Type | Fixed |
| Connection Type | Screw terminals |
| Protection Class | IP20 (with front cover) |
| Standards | IEC 60947-2 |
| Operating Temperature Range | -25°C to +55°C |
Core Features & Market Positioning
The Siemens 3VA1120-5EE32-0AA0 distinguishes itself through its high breaking capacity of 55kA, providing superior short-circuit protection crucial for critical industrial power systems. Its advanced LSI (Long-time, Short-time, Instantaneous) trip unit offers flexible and precise overcurrent coordination, optimizing selectivity and minimizing nuisance tripping. This breaker is positioned as a reliable, high-performance solution for engineers and facility managers prioritizing safety, operational continuity, and equipment longevity. Its robust construction and adherence to international standards like IEC 60947-2 underscore its suitability for heavy-duty applications, setting it apart from lower-rated alternatives in the market.
Key Application Scenarios
This 3VA11 series air circuit breaker is ideally suited for a wide array of industrial applications where robust overcurrent and short-circuit protection is paramount. It finds extensive use in main distribution boards and sub-distribution boards within manufacturing plants, data centers, and commercial buildings. The 20A rating and 55kA breaking capacity make it a perfect fit for safeguarding motor feeders, transformer feeders, and capacitor banks, ensuring stable power delivery and preventing costly equipment damage. Its versatility extends to generator protection and as a main incoming feeder breaker in medium-sized facilities, providing a reliable point of isolation and protection.
Practical System Integration Guidance
Integrating the Siemens 3VA1120-5EE32-0AA0 into existing electrical systems is streamlined due to its standardized design and connection options. The breaker utilizes robust screw terminals for secure power connections, accommodating appropriate conductor sizes as per IEC standards for the 20A rating. Proper torque must be applied to ensure a reliable electrical connection and prevent overheating. For optimal system integration and protection coordination, it is recommended to consult the detailed technical documentation and application guides provided by Siemens, especially when configuring the LSI trip unit settings to match specific load characteristics and upstream/downstream protective devices. Ensure adequate clearance is maintained around the breaker for ventilation and safe operation.
Operation and Risk Mitigation
Safe operation of the Siemens 3VA1120-5EE32-0AA0 3VA11 series air circuit breaker relies on adherence to established electrical safety protocols and proper understanding of its functionalities. The breaker is designed with clear operating levers (ON/OFF/TRIPPED) and a mechanical trip button for manual intervention. In the event of a fault, the breaker will trip, indicated by the lever's position. If the breaker fails to trip under fault conditions, immediate de-energization and professional inspection are critical to mitigate risks of electrical arcing or equipment failure. Regular visual inspections for damage or signs of overheating, along with periodic functional testing, are essential risk mitigation measures.
Scalability & Long-Term Value
The Siemens 3VA1120-5EE32-0AA0 offers significant long-term value through its inherent reliability and compatibility within the broader Siemens industrial automation ecosystem. While this specific model is a fixed-type breaker, its integration capabilities within panel builders' solutions and compatibility with various auxiliary and signaling components allow for system expansion and enhanced monitoring. For facilities adopting Industry 4.0 principles, the 3VA series can be equipped with communication modules, enabling seamless integration into digital monitoring and control platforms for predictive maintenance and energy management, thereby future-proofing electrical infrastructure.
Frequently Asked Questions (FAQs)
Q1: What is the primary function of the Siemens 3VA1120-5EE32-0AA0?
This circuit breaker's main role is overcurrent protection. It safeguards electrical circuits from damage caused by excessive current levels.
It detects both prolonged overloads and sudden short circuits. The device then quickly interrupts the flow of electricity to prevent harm.
This ensures the safety of personnel, prevents equipment damage, and maintains operational continuity.
Q2: What does the "55kA" rating signify for this breaker?
The "55kA" denotes the short-circuit breaking capacity. This is the maximum fault current the breaker can safely interrupt.
It indicates the breaker's ability to withstand and clear severe short-circuit events without sustaining damage. This is crucial for high-fault current industrial environments.
A higher breaking capacity provides a greater safety margin and protects downstream equipment more effectively during intense faults.
Q3: Can the Siemens 3VA1120-5EE32-0AA0 be used for motor protection?
Yes, with its LSI trip unit, it is suitable for motor protection applications. The adjustable settings allow for coordination with motor start-up characteristics.
The long-time delay can be set to accommodate inrush currents during motor starting. The short-time and instantaneous functions protect against direct short circuits.
Proper configuration of the trip unit's settings is essential for effective and reliable motor protection.
Q4: What is the difference between a 3-pole and a 1-pole breaker?
A 3-pole breaker simultaneously disconnects all three phases of a three-phase power supply. This is standard for industrial three-phase loads.
A 1-pole breaker is designed for single-phase circuits, typically used in residential or lighter commercial applications. It only interrupts one conductor.
For industrial motor and equipment protection, a 3-pole breaker like the 3VA1120-5EE32-0AA0 is necessary for complete isolation.
Q5: How do I reset the Siemens 3VA1120-5EE32-0AA0 after a trip?
After a trip, you must first identify and rectify the cause of the fault. Once the fault is cleared, move the operating lever fully to the "OFF" position.
Then, you can push the lever firmly to the "ON" position to re-energize the circuit. Ensure all safety checks are completed.
If the breaker trips again immediately, there may be an ongoing fault that requires professional diagnosis.
Q6: What standards does the 3VA11 series comply with?
The 3VA11 series, including this breaker, complies with IEC 60947-2. This is the international standard for low-voltage switchgear and controlgear.
Compliance with IEC 60947-2 ensures the breaker meets rigorous performance and safety requirements for its intended applications.
Adherence to these standards guarantees a high level of reliability and interoperability in global electrical installations.
Q7: What is the role of the thermal-magnetic release in this breaker?
The thermal element provides protection against sustained overloads. It reacts to the heat generated by prolonged overcurrents.
The magnetic element offers protection against short circuits. It responds instantaneously to very high fault currents.
Together, they provide a comprehensive overcurrent protection solution tailored to various fault scenarios.
Q8: Can I change the 20A rating of this breaker?
No, the rated current of an air circuit breaker is fixed. This model is specifically rated for 20A.
If a different current rating is required, a different breaker model must be selected. It is not possible to adjust the fundamental current rating of this unit.
Selecting the correct breaker rating from the outset is crucial for proper system protection and compliance.
Q9: What are the typical installation requirements for this breaker?
Install the breaker in a clean, dry environment within its specified operating temperature range. Ensure adequate ventilation around the unit to prevent overheating.
Connect conductors securely using appropriately sized cables and torqued screw terminals. Follow local electrical codes and manufacturer guidelines.
The breaker should be mounted in a suitable enclosure or distribution board designed for air circuit breakers.
Q10: Does Siemens offer accessories for the 3VA1120-5EE32-0AA0?
Yes, Siemens provides various accessories for the 3VA11 series. These include auxiliary and alarm switches for remote signaling.
Other accessories might include plug-in modules for enhanced communication capabilities or specific mounting kits.
These accessories allow for customization and integration into more complex control and monitoring systems.
