Siemens Circuit breaker for motor protection, size S0, 1NO+1NC Part number 3RV2021-1CA15

Product Overview

The Siemens 3RV2021-1CA15 is a compact SIRIUS 3RV2 motor-protection circuit breaker (size S0) designed for reliable protection of three-phase motors. It provides thermal (overload) and magnetic (short-circuit) protection, manual switching, and integrated auxiliary signalling. With a Class 10 trip curve, adjustable current range, and robust switching capacity, it is ideal for industrial motor-control centers and automation systems.

Key Features

• Motor-protection circuit breaker, size S0
• Class 10 tripping characteristic for standard motor starting
• Thermal overload protection with adjustable A-release: 1.8…2.5 A
• Magnetic N-release for short-circuit protection: 33 A
• Standard switching capacity for industrial motor circuits
• Three-pole design for 3-phase motors and loads
• Screw terminals for secure wiring and fast installation
• Integrated transverse auxiliary switches (1 NO + 1 NC) for signalling and interlocking
• Suitable for use in motor starters, control panels, and MCCs

Technical Specifications

• Article Number: 3RV2021-1CA15
• Product Series: SIRIUS 3RV2
• Circuit Breaker Size: S0
• Poles: 3-pole
• Thermal Overload Release (A-release): Adjustable 1.8…2.5 A
• Magnetic Short-Circuit Release (N-release): 33 A
• Trip Class: Class 10
• Rated Operating Voltage: Up to 690 V AC
• Switching Capacity: Standard switching capacity for motor protection (SIRIUS size S0)
• Auxiliary Switches: Transverse 1 NO + 1 NC (integrated)
• Terminal Type: Screw terminal
• Mounting: DIN-rail (35 mm)
• Ambient Temperature: –20 °C to +60 °C
• Functions: Overload protection, short-circuit protection, manual ON/OFF switching

Compliance & Standards

• SIRIUS 3RV2 motor-protection standard
• Complies with IEC and EN requirements for low-voltage motor protection
• Suitable for isolating, switching, and protecting three-phase motors

Applications

Ideal for protecting motors such as pumps, fans, conveyors, compressors, and general machinery. Commonly used in automation panels, motor control centers, and industrial machines requiring compact motor protection with Class 10 characteristics. The integrated auxiliary contacts allow status signalling and interlocks within control circuits.