Siemens SIRIUS Domestic Control and Protection System

Siemens Domestic SIRIUS Series: Complete Engineering Practice of Modular Control and Protection Systems

In the field of industrial automation and electrical control, as the core driving unit, the reliable control and safety protection of electric motors are of paramount importance in ensuring production continuity and equipment safety. Siemens' domestically produced SIRIUS series control and protection products, with their modularity, systematization, high reliability, and complete global certification, provide a complete solution for the Chinese and global markets from micro to medium power range (up to 250kW). This article will systematically deconstruct and analyze the four core components of the SIRIUS series -3RV6/3RV5 circuit breakers, 3RT6/3RT5 contactors, 3RH6 intermediate relays, and 3RU6/3RU5 thermal overload relays - based on the 2020 product sample.

System Overview: The Essence of Modular Design

The SIRIUS (domestic) series is not a single product, but a highly coordinated modular ecosystem. Its core advantages lie in:

Unified design language: All components share similar installation dimensions (such as 45mm standard width), wiring methods (mainly screw terminals), and accessory interfaces, greatly simplifying cabinet layout and assembly.

Seamless mechanical and electrical connection: For example, the 3RU thermal overload relay can achieve a "perfect connection" with the 3RT contactor through dedicated connectors, without the need for additional wiring, reducing contact resistance and installation time.

Comprehensive certification system: Our products have obtained authoritative certifications such as CCC (China), UL (United States), CSA (Canada), CE (European Union), CCS (China Classification Society), LR (Lloyd's Register), etc., meeting the access requirements of major global markets and clearing obstacles for equipment exports.

Rich CAx data support: Provides comprehensive computer-aided design documents for engineers to quickly select, layout, and generate material lists in EDA software.

3RV6/3RV5 Circuit Breakers: Precise Line and Motor Protection Experts

As the first protective barrier in the system, 3RV6/3RV5 circuit breakers provide current coverage from 16A to 100A, including four compact specifications of S00, S0, S2, and S3.

1. Core functions and model differentiation:

3RV60/3RV50 (motor protection type): equipped with adjustable thermal overload release and fixed 13 times In instantaneous magnetic release, designed specifically for protecting three-phase induction motors, with phase loss protection function. At 400V AC, it can protect motor power up to 45kW (S3 specification).

3RV63/3RV53 (starter combination short-circuit protection type): Only equipped with magnetic release (13 times In), does not include overload protection function, must be used in conjunction with 3RU thermal overload relay and 3RT contactor to form a complete starting protection combination.

3RV64/3RV54 (Transformer Protection Type): The magnetic trip value is fixed at 20 times In, designed to withstand high surge currents when the transformer is connected and avoid false tripping.

2. Key technical features:

Class 10 tripping level: Ensure that the tripping time is within 4-10 seconds under 7.2 times the cold current, suitable for motors with standard starting conditions.

High breaking capacity: Under 400V AC, the rated ultimate short-circuit breaking capacity (Icu) can reach up to 100kA, and some models can reach over 50kA, providing reliable short-circuit protection.

Flexible accessories: Support the installation of auxiliary contacts (indicating switch status), fault signal contacts (distinguishing between overload and short-circuit tripping), shunt/undervoltage release devices, and door coupling rotating operating mechanisms to achieve safe operation and locking of cabinet doors.

3RT6/3RT5 contactors: reliable power switching core

The contactor is a direct component that performs motor start stop operations. SIRIUS contactors cover seven specifications from S00 to S12, with rated power ranging from 3kW to 250kW.

1. Design highlights and general features:

Wide range of coil voltage: Supports AC (24-600V) and DC (24-2220V) operation, S6 and above specifications use AC/DC universal coils and integrate varistor surge suppressors.

Modular contact expansion: In addition to the integrated contacts of the main body, all specifications can be equipped with auxiliary contact blocks (installed on the front or side). S00/S0 specifications can be expanded to a maximum of 6 contacts, and S3 specifications can be expanded to a maximum of 8 contacts.

High contact reliability: maintains extremely high reliability (failure rate<10 ^ -8) even at signal levels as low as 17V/1mA, suitable for solid-state circuit control such as PLC.

Reversible contactor combination: By using mechanical interlocking modules (such as 3RA1924-2B) and connecting clamps, the forward and reverse starting circuits can be safely and conveniently assembled to prevent power phase short circuits.

2. Overview of Technical Parameters:

Taking common specifications as an example:

S0 specification (3RT602): Width 45mm, AC-3 rated current 9-38A, corresponding to 400V motor power 4-18.5kW, mechanical life up to 10 million cycles.

S3 specification (3RT504): Width 70mm, AC-3 rated current 65-95A, corresponding to 400V motor power of 30-45kW, rated insulation voltage up to 1000V.

S12 specification (3RT507): Maximum specification, AC-3 rated current up to 400-500A, capable of controlling 250kW motors at 400V.

3RH6 intermediate relay: flexible control logic expansion

The 3RH61 4-pole intermediate relay serves as an amplification and isolation unit for control signals, and is a bridge connecting PLC weak current signals with contactor coils.

Compact design: Adopting S00 specifications (45mm wide), the body integrates 4 contacts (configurable as 2NO+2NC, 3NO+1NC, etc.).

High reliability: It also meets the high reliability requirements at 17V/1mA and is suitable for small control signals.

Strong compatibility: Its accessories (auxiliary contact block, surge suppressor) are fully compatible with S00 standard contactors, reducing spare parts inventory costs.

3RU6/3RU5 Thermal Overload Relay: Precise Overload and Phase Loss Guardian

As the ultimate execution unit for motor overload protection, the 3RU series works in conjunction with the 3RT contactor.

Precise protection: Provides Class 10 trip level with environmental temperature compensation function (some models have a compensation range of -40 ° C to+60 ° C), ensuring that the set current is not affected by environmental temperature.

Humanized design: Integrated manual/automatic reset selection, testing button, trip status indicator, and stop button for easy on-site debugging and operation.

Complete product line:

3RU6116/3RU6126: Suitable for S00/S0 contactors, with a current setting range of 0.11-40A.

3RU5136/3RU5146: Suitable for S2/S3 contactors, with a current setting range of 5.5-100A.

3RU5156/3RU5176: High current model, suitable for S6/S10/S12 contactors, with a current setting range of 55-500A.

Flexible installation: You can choose to directly plug it into the corresponding contactor or install it separately through an independent mounting bracket.

Attachment ecosystem: achieving customized functionality

The strength of the SIRIUS system is largely due to its rich accessory system, which enables standard products to adapt to ever-changing application scenarios.

Connection system: The three-phase insulated busbar (3RV1915) can quickly and clearly connect multiple parallel circuit breakers; The contactor circuit breaker connection module (such as 3RA1921) enables direct electrical and mechanical connection between the two.

Operation and instruction accessories: door coupling operating mechanism, various auxiliary contacts, signal contacts, mechanical reset extension rod, etc.

Protective accessories: Various types of surge suppressors (resistors, varistors, diodes) are used to suppress overvoltage generated when the contactor/relay coil is disconnected and protect the control circuit.

Certification and Reliability Assurance

The entire series of products comply with international standards such as IEC/EN 60947, and have obtained multiple certifications such as CCC, CE, UL, etc. This is not only a passport to market access, but also a reflection of their design, materials, and manufacturing processes reaching international safety and quality standards. The mechanical and electrical lifespan parameters, reaching millions of cycles, provide data support for the long-term, fault free operation of the equipment.