Siemens SIRIUS 3RV2 Motor Starter Protector Circuit Breaker 3RV2031-4PA10, 3-Pole, 28-32 A, 690 V AC, Class 10, Screw Terminals

Motor protection can be a weak link in industrial installations—thermal overloads and short circuits cause costly downtime and equipment damage. The Siemens SIRIUS 3RV2 motor starter protector (MSP) closes that gap by combining a circuit breaker and thermal overload relay in one compact, DIN-rail-mountable unit. The 3RV2031-4PA10 is a 3-pole, Class 10 device with an adjustable thermal release from 28 to 32 A and a fixed magnetic release at 416 A, rated for operational voltages up to 690 V AC. It provides reliable protection for three-phase motors in demanding environments.

Who is it for

This MSP is built for panel builders, maintenance engineers, and machine OEMs who need a space-saving, high-performance protection device for standard three-phase motors up to 32 A. It is ideal for industrial control panels, pump stations, conveyor systems, and HVAC applications where reliable motor protection and quick fault isolation are essential.

Main features

• Combined short-circuit and overload protection in a single 45 mm wide module
• Adjustable thermal trip setting from 28 to 32 A to match motor full-load current
• Fixed magnetic trip at 416 A for instantaneous short-circuit response
• Class 10 tripping characteristic for normal motor starting conditions
• High breaking capacity: 50 kA at 400 V AC
• Rated insulation voltage 690 V, impulse withstand 6 kV
• Screw terminals for secure, maintenance-friendly wiring
• Mounts on standard 35 mm DIN rail or with screw fixing
• IP20 protection on front face; suitable for enclosed panels
• Long service life: 100,000 electrical and 10,000,000 mechanical operations

Specifications

• Brand: Siemens
• Series: SIRIUS 3RV2
• Size: S0
• Number of poles: 3
• Adjustable current range: 28 – 32 A
• Instantaneous short-circuit release: 416 A
• Rated operational voltage Ue: 690 V AC
• Rated insulation voltage Ui: 690 V
• Rated impulse withstand voltage Uimp: 6 kV
• Short-circuit breaking capacity Icu at 400 V AC: 50 kA
• Tripping class: Class 10
• Overload release type: Thermal
• Short-circuit release type: Magnetic
• Mounting: 35 mm DIN rail or screw fixing
• Connection: Screw terminals
• Protection class: IP20 (front)
• Ambient operating temperature: -20 °C to +60 °C
• Electrical service life: 100,000 switching cycles
• Mechanical service life: 10,000,000 switching cycles
• Product type: Motor starter protector / circuit breaker

Tips

Set the thermal release to the motor's rated full-load current as shown on the nameplate. For motors with high inrush currents, verify that the Class 10 characteristic allows starting without nuisance tripping. Always install inside a suitable enclosure to maintain the IP20 rating and protect against accidental contact.