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: