Siemens 3RH1921-2CA10 SIRIUS Auxiliary Switch 1NO Spring Terminal 3RT1

The Siemens 3RH1921-2CA10 is a SIRIUS front-mounted auxiliary switch with 1 normally open (NO) instantaneous contact and spring-type terminals, designed to snap onto the front of 3RT1 contactors. It carries an insulation voltage of 690 V AC (pollution degree 3) and a surge voltage resistance of 6 kV, suitable for a wide range of industrial motor control circuits.

Technical specifications:

• MLFB: 3RH1921-2CA10
• Manufacturer: Siemens
• Product line: SIRIUS
• Product type designation: 3RH19
• Contact arrangement: 1 NO instantaneous (0 NC, 0 CO)
• Insulation voltage: 690 V AC (pollution degree 3)
• Surge voltage resistance: 6 kV
• Operational current at AC-15 / 690 V: 1 A
• Operational current at AC-12 / 24 V and 230 V: 10 A
• IP rating: IP20 (front)
• Mechanical service life: 10,000,000 operating cycles
• Electrical endurance at AC-15 / 230 V: 200,000 operating cycles
• Contact reliability: 1 faulty switching per 100 million at 17 V / 1 mA
• Operating temperature: -25 to +60°C
• Storage temperature: -55 to +80°C
• Mounting: snap-on to front of contactor
• Compatible contactors: 3RT10, 3RT12, 3RT145, 3RT146, 3RT147
• Terminal type: spring-loaded
• Conductor cross-section: 0.5 to 2.5 mm² solid/stranded, AWG 20-14
• Dimensions (W x H x D): 10 x 38 x 51 mm
• Weight: 0.018 kg

Features and benefits:

• Front snap-on mounting enables fast, tool-free installation on 3RT1 contactors
• Spring-loaded terminals accept 0.5 to 2.5 mm² conductors with or without ferrules
• Mirror contact function per IEC 60947-4-1 (with 3RT1) for safety-critical control circuits
• Exceptional mechanical service life of 10,000,000 operating cycles
• High contact reliability: 1 faulty switching per 100 million operations at 17 V / 1 mA
• Wide operating temperature range of -25 to +60°C for demanding environments

Applications:

• Expanding the auxiliary contact complement of SIRIUS 3RT1 contactors
• Feedback and status signaling in motor starter assemblies
• Interlocking circuits in industrial control panels and switchgear
• Safety monitoring requiring mirror contact verification per IEC 60947-4-1
• Low-current PLC input signaling at 17 V / 1 mA

Compliant with IEC 60947-4-1 (mirror contact) and IEC 60947-5-1. Part of the Siemens SIRIUS 3RH19 range.

Also known as: Siemens 3RH1921-2CA10, SIRIUS front auxiliary switch, 3RH19 auxiliary switch for 3RT1.