Siemens 3RT2024-2KB40 Power Contactor 3P 12A 5.5kW 24VDC

The Siemens 3RT2024-2KB40 is a 3-pole SIRIUS power contactor rated 12 A / 5.5 kW at 400 V (AC-3), designed for switching three-phase induction motors. It features a 24 V DC coil with an operating range of 0.7-1.25 x Uc for direct connection to PLC digital outputs, and includes a plugged-in varistor and integrated 1 NO + 1 NC auxiliary contacts.

Technical specifications:

• MLFB: 3RT2024-2KB40
• Manufacturer: Siemens
• Product line: SIRIUS
• Product type designation: 3RT2
• Frame size: S0
• Number of main poles: 3
• Rated current at AC-3 (400 V): 12 A
• Rated current at AC-1 (400 V, 40°C): 40 A
• Rated power at AC-3 (400 V): 5.5 kW
• Rated power at AC-3 (690 V): 7.5 kW
• Max operating voltage (AC-3 / AC-3e): 690 V
• Control supply voltage: 24 V DC
• Coil operating range: 0.7-1.25 x Uc
• Auxiliary contacts: 1 NO + 1 NC
• Terminal type: Spring-loaded
• Surge suppressor: Plugged-in varistor
• Insulation voltage (main and auxiliary circuits): 690 V
• Surge voltage resistance: 6 kV
• Ambient operating temperature: -25 to +60°C
• Storage temperature: -55 to +80°C
• Mechanical service life: 10,000,000 operating cycles
• Max installation altitude: 2,000 m
• Auxiliary switch addition: Not possible

Features and benefits:

• 24 V DC coil with 0.7-1.25 x Uc tolerance allows direct connection to standard PLC outputs
• Spring-loaded terminals reduce wiring time and eliminate screw-torque errors during installation
• Plugged-in varistor suppresses coil voltage transients on de-energization, protecting control circuits
• Rated for AC-3e duty class, supporting enhanced motor switching efficiency
• 10,000,000 mechanical operating cycles for extended service intervals
• Compact S0 frame size suits space-constrained control cabinets

Applications:

• Starting and stopping three-phase induction motors in AC-3 and AC-3e duty
• PLC-driven automation panels where 24 V DC contactors are controlled directly from digital outputs
• Pump, fan, and compressor motor control in industrial and building installations
• Conveyor and machine drive control in manufacturing environments

Compliant with EN/IEC 60947-4-1. Part of the Siemens SIRIUS 3RT2 range.

Also known as: Siemens 3RT2024-2KB40, SIRIUS 3RT2 contactor 12A 24VDC, Siemens S0 power contactor.