Siemens 5SY6325-7CC Industrial Miniature Circuit Breaker 3P 25A
The Siemens 5SY6325-7CC is a robust 3-pole miniature circuit breaker (MCB) designed for reliable electrical protection in industrial and commercial applications. Engineered for demanding environments, this 3P 25A device offers a 6kA breaking capacity, ensuring it can safely interrupt fault currents. Its C-type tripping characteristic makes it suitable for circuits with moderate inrush currents, such as those found in motor control or lighting applications. The Siemens 5SY6325-7CC is a key component in ensuring operational safety and system integrity.
Product Specifications
| Specification | Value | |
| :-------------------------- | :----------------------------------- | :------------------------- |
| Product Number | 5SY6325-7CC | |
| Poles | 3P | |
| Rated Current | 25A | |
| Tripping Characteristic | C | |
| Breaking Capacity (IEC) | 6 kA | |
| Breaking Capacity (IEC/UL) | 15 kA | |
| Rated Voltage (AC) | 400V | |
| Insulation Voltage (Ui) | 440V | |
| Degree of Pollution | 3 | |
| Overvoltage Category | III | |
| Energy Limitation Class | 3 | |
| Connection Type | Screw Terminals | |
| Conductor Cross-Section (Solid) | 0.75 - 35 mm² | |
| Conductor Cross-Section (Stranded) | 0.75 - 35 mm² | |
| Conductor Cross-Section (Finely Stranded with Ferrules) | 0.75 - 25 mm² | |
| Tightening Torque | 2.5 - 3.5 N·m | |
| Dimensions (H x W x D) | 90 mm x 54 mm x 76 mm | |
| Installation Depth | 70 mm | |
| Width Units | 3 | |
| Mounting Type | DIN Rail | |
| Protection Class | IP20 (with connected conductors) | |
| Operating Temperature Range | -25°C to 55°C | |
| Storage Temperature Range | -40°C to 75°C | |
| Mechanical Service Life | 10,000 cycles | |
| Standards | IEC/EN 60898-1, IEC/EN 60947-2, UL1077 | |
| RoHS Compliance | Yes | |
Core Features & Market Positioning
The Siemens 5SY6325-7CC is positioned as a reliable and versatile supplementary protector within the SENTRON product line, renowned for its high quality and robust performance in industrial control and distribution systems. Its market strength lies in its adherence to stringent international standards, including IEC/EN and UL, making it suitable for global applications. Unlike primary branch circuit protectors, this MCB is designed to offer enhanced selectivity and protection for sensitive loads, particularly in scenarios involving multiple motor control circuits or power supplies. This differentiation allows users to precisely pinpoint fault locations without disrupting entire systems, thereby minimizing downtime and operational losses. The C-curve characteristic, offering a trip range of 5-10 times the rated current for short circuits, is ideal for inductive loads that experience higher inrush currents during startup. Its compatibility with a wide array of supplementary components, such as auxiliary switches and shunt releases, further enhances its value proposition by allowing for customized system configurations and advanced protection strategies.
Key Application Scenarios
The Siemens 5SY6325-7CC miniature circuit breaker finds critical application in various industrial settings where precise and selective overcurrent protection is paramount. It is extensively used in control cabinets for industrial machinery, providing protection for motor control circuits, power supplies for control systems, and other sensitive electronic equipment. In panel building, it serves as a supplementary protector, offering enhanced discrimination between faults in parallel circuits or on the secondary side of control transformers, thereby preventing nuisance tripping of main breakers. Its C-curve characteristic is particularly advantageous for protecting circuits with moderate inductive loads, such as small to medium-sized motors, solenoid valves, and certain types of lighting systems, where brief current surges during operation are expected. Furthermore, its suitability for use in applications requiring UL 1077 supplementary protection opens doors for its use in specialized industrial equipment destined for markets with these specific certification requirements.
Practical System Integration Guidance
Integrating the Siemens 5SY6325-7CC into existing or new electrical systems is a straightforward process due to its user-friendly design. The device is designed for quick and tool-free mounting and dismounting onto standard 35mm DIN rails. It features clearly marked terminals for secure conductor connections. For solid conductors, a cross-section range of 0.75 mm² to 35 mm² is supported, while finely stranded conductors with ferrules can range from 0.75 mm² to 25 mm². The recommended tightening torque for screw terminals is between 2.5 to 3.5 N·m, ensuring a reliable connection without overtightening. The MCB offers combined terminals at both the top and bottom, allowing for flexible infeed options, which simplifies wiring and installation in confined spaces. Importantly, the 5SY6325-7CC is designed as a supplementary protector, meaning it is intended to be used in conjunction with a primary branch circuit protection device, not as a standalone overcurrent protection for the entire circuit.
Operation and Risk Mitigation
The Siemens 5SY6325-7CC operates on the principle of thermal and magnetic tripping mechanisms to protect electrical circuits. The thermal element, a bimetallic strip, responds to sustained low-level overcurrents by bending and triggering the trip mechanism, protecting against overloads. The magnetic element provides instantaneous tripping for high short-circuit currents, safeguarding equipment from severe damage. The C-curve characteristic means that the MCB will trip when the current reaches 5 to 10 times its rated current, which is suitable for inductive loads that may experience temporary inrush currents. To mitigate risks, proper installation is crucial; ensure all connections are secure and torqued correctly to prevent overheating or loose contacts. Electrical personnel should always disconnect power before performing any maintenance or inspection. The device is designed with touch protection, offering safety against accidental contact with live parts when installed correctly. While specific fault codes are not typically associated with MCBs of this type, operational issues usually manifest as unintended tripping. If the 5SY6325-7CC trips frequently, it indicates an overload condition or a potential fault in the protected circuit, requiring thorough investigation.
Scalability & Long-Term Value
The Siemens 5SY6325-7CC offers significant long-term value through its integration capabilities and Siemens' commitment to product lifecycle support. As part of the broader SENTRON protection device portfolio, it seamlessly integrates with other Siemens components, including supplementary devices like auxiliary contacts for remote signaling, shunt releases for remote tripping, and undervoltage releases for system protection. This modular approach allows for system expansion and upgrades without requiring a complete overhaul of existing infrastructure. For industrial applications increasingly focused on digitalization and the Industrial Internet of Things (IIoT), the 5SY6325-7CC can be part of a smart electrical distribution system. While not an IIoT device itself, it can be coupled with intelligent measurement and monitoring devices from Siemens that provide real-time data on energy consumption and circuit status, enabling predictive maintenance and optimized energy management. The product's active lifecycle status ensures continued availability and support from Siemens.
Frequently Asked Questions (FAQs)
Q1: What is the primary function of the Siemens 5SY6325-7CC?
The Siemens 5SY6325-7CC acts as a miniature circuit breaker, providing overcurrent and short-circuit protection. It is specifically designed as a supplementary protector.
It safeguards electrical circuits from damage caused by excessive current. This prevents equipment failure and potential fire hazards.
Its C-curve tripping characteristic makes it ideal for circuits with moderate inrush currents, common in industrial applications.
Q2: What are the key technical specifications of the 5SY6325-7CC?
This MCB features 3 poles and a rated current of 25A. It has a breaking capacity of 6kA according to EN 60898.
The device operates on AC voltage up to 400V and has an insulation voltage of 440V. Its tripping characteristic is type C.
It supports conductor cross-sections from 0.75mm² to 35mm² and mounts on a standard DIN rail.
Q3: Where is the Siemens 5SY6325-7CC typically used?
This circuit breaker is commonly found in industrial control cabinets and panel building applications. It protects motor control circuits and power supplies.
It serves as a supplementary protector to enhance selectivity in complex electrical systems. This helps isolate faults without disrupting overall operations.
Applications include protection for lighting, solenoid valves, and other inductive loads with moderate inrush currents.
Q4: What does the 'C' in 5SY6325-7CC signify?
The 'C' denotes the tripping characteristic of the circuit breaker. It specifies how quickly the breaker will trip under fault conditions.
A Type C breaker is designed to trip between 5 to 10 times its rated current for short circuits. This accommodates higher inrush currents typical of inductive loads.
This characteristic is suitable for general-purpose applications like motor controls, transformers, and lighting circuits.
Q5: Can the 5SY6325-7CC be used as a main circuit breaker?
No, the Siemens 5SY6325-7CC is designated as a supplementary protector. It is not intended for primary branch circuit protection.
It is designed to work in conjunction with a main circuit breaker to provide enhanced protection. This ensures greater selectivity and finer fault discrimination.
Using it as a main breaker would compromise the overall safety and protective coordination of the electrical system.
Q6: What is the breaking capacity of the Siemens 5SY6325-7CC?
The Siemens 5SY6325-7CC has a breaking capacity of 6 kA according to EN 60898 standards. It also offers a higher breaking capacity of 15 kA per IEC 60947-2.
This rating indicates the maximum fault current the breaker can safely interrupt without sustaining damage. It is crucial for ensuring system safety during short-circuit events.
The 6kA rating is standard for many residential and commercial applications, while the 15kA offers enhanced protection for more demanding industrial environments.
Q7: How is the 5SY6325-7CC installed?
Installation is typically done via a standard 35mm DIN rail, allowing for tool-free mounting and dismounting. This ensures quick and easy setup.
Conductors are connected using screw terminals, supporting a wide range of solid and stranded wire sizes. Proper torque is essential for secure connections.
The breaker features combined terminals at the top and bottom for flexible infeed options, simplifying wiring configurations.
Q8: What conductor sizes can be connected to the 5SY6325-7CC?
Solid conductors can range from 0.75 mm² to 35 mm². This offers flexibility for various wiring needs.
For finely stranded conductors with core end processing, the range is from 0.75 mm² to 25 mm².
This broad compatibility ensures it can be integrated into a wide spectrum of electrical installations and equipment.
Q9: What is the impact of ambient temperature on the 5SY6325-7CC's performance?
The operational current of the breaker is affected by ambient temperature. For example, at 40°C, the operational current is 23.8A, decreasing at higher temperatures.
The device is rated for operation in ambient temperatures from -25°C up to 55°C. It can also withstand humidity up to 95% RH within this range.
Operating outside these specified temperature limits can affect its performance and lifespan, and potentially lead to nuisance tripping or failure to trip.
Q10: What supplementary components can be used with the 5SY6325-7CC?
The 5SY6325-7CC is compatible with various supplementary devices from Siemens. These include auxiliary contacts for signaling and fault signal contacts.
It can also be combined with shunt releases for remote tripping and undervoltage releases for system protection. RCCB units can also be integrated for residual current protection.
This modularity allows for tailored system configurations, enhancing both functionality and safety beyond basic overcurrent protection.
