Siemens Circuit Breaker 3RV2331-4VC10

Siemens SIRIUS 3RV2 – Motor Protection Circuit Breaker

Typical Applications & Industries:
✓ Three-phase induction motor protection ✓ Motor starter combinations (with SIRIUS 3RT contactors)
✓ Pump, fan, and conveyor systems ✓ Machine tools and production lines
✓ Transformer and system protection ✓ Control panel and switchgear engineering
✓ IE3/IE4 high-efficiency motor compatibility

Detailed Description – Siemens SIRIUS 3RV2 Motor Protection Circuit Breaker

1. Series Overview – Compact Motor Protection for Load Feeders

The SIRIUS 3RV2 is a compact, current-limiting motor protection circuit breaker designed specifically for load feeders and three-phase motor protection. It combines thermal overload protection, magnetic short-circuit protection, phase failure detection, and a disconnector function in a single device, replacing the traditional combination of a thermal overload relay, a short-circuit protection device, and a separate switch .

The 3RV2 portfolio spans four frame sizes — S00, S0, S2, and S3 — covering motor power ratings from approximately 0.04 kW to 55 kW at 400 V AC, with rated currents up to 100 A .

2. Protection Functions

Thermal Overload Protection (ANSI 49) – An adjustable bimetallic release responds to sustained overcurrent. The setting dial allows precise matching to the motor’s full-load current, typically across a 0.7 to 1.0 × In range. Trip class CLASS 10 is standard, suitable for most motor starting conditions .

Magnetic Short-Circuit Protection (ANSI 50) – A fixed magnetic release provides instantaneous tripping on high fault currents. The trip threshold is factory-set at approximately 13× In to allow motor inrush while clearing faults rapidly .

Phase Failure Detection – A differential release mechanism ensures rapid tripping if one phase is lost, preventing damaging single-phase operation .

Disconnector Function – The 3RV2 provides isolation per IEC 60947-2, allowing it to serve as a main switch or emergency stop device. An integrated locking mechanism prevents unauthorized access and ensures trouble-free operation .

3. Frame Sizes and Power Ratings

The 3RV2 is available in four frame sizes, each optimized for specific motor power ranges :

4. Modular SIRIUS System Integration

The 3RV2 is part of the SIRIUS modular system, enabling seamless integration with other components :

• Direct mounting onto SIRIUS 3RT contactors via connection modules

• Auxiliary contacts (1 NO + 1 NC standard) for status signaling

• Undervoltage and shunt releases for remote or automatic tripping

• Surface-mounting enclosures available for stand-alone installation

• Connection modules for screw, spring-type, or ring cable lug termination

This modularity reduces wiring effort, saves panel space, and ensures coordinated Type 2 protection across the motor feeder .

5. Short-Circuit Breaking Capacity

The 3RV2 offers high short-circuit breaking capacity without requiring back-up fuses in most applications :

• S00/S0 sizes: Up to 100 kA at 240 V, 400 V, and 500 V AC

• S2/S3 sizes: Up to 55 kA at 400 V AC (higher with back-up fuses)

6. Compatibility with High-Efficiency Motors

The 3RV2 is optimized for use with IE3 and IE4 high-efficiency motors, which have different starting and thermal characteristics than older motor designs. Siemens provides specific selection tables and configuration guidance for these motors .

7. Global Certifications

The 3RV2 carries comprehensive international approvals :

• IEC/EN 60947-2 (circuit breakers)

• IEC/EN 60947-4-1 (motor starters)

• UL 60947-4-1 / CSA C22.2 (North America)

• CCC (China), EAC (Eurasian)

• Marine approvals available

Selection Guide – Understanding the Naming Convention (Siemens 3RV2 Series)

Part Number Format: 3RV2 [Size] [Current Code] [Connection] - [Options]

Example: 3RV2021-4EA20-0BA0

Model Decoder Examples: