Siemens Power contactor, 3-pole, 1NO + 1NC, 400V, 7.5kW, 10A Part number 3RT2025-1KB40

Product Overview

The Siemens 3RT2025-1KB40 is a SIRIUS 3RT-series 3-pole power contactor (size S0) with a 24 V DC control coil and integrated varistor. It is designed for switching three-phase motors or loads up to 7.5 kW at 400 V AC (or equivalent load ratings under AC-3/AC-3e conditions). Its compact size, screw-terminal wiring and auxiliary contact make it suitable for control panels, motor starters and automation installations — especially where PLC-driven control or compact motor switching is required.

Key Features

• 3-pole power contactor, size S0 (SIRIUS 3RT series)
• Rated operational current: 17 A (AC-3 / AC-3e)
• Rated motor load switching capacity: up to 7.5 kW at 400 V AC
• Control coil: 24 V DC — suitable for PLC and low-voltage control circuits
• Integrated varistor for coil surge protection
• Auxiliary contacts: 1 NO + 1 NC (for control / signalling circuits)
• Screw-type terminals for main, control and auxiliary circuits
• Compact S0 frame — suitable for space-efficient panel or control-cabinet installations
• Suitable for frequent switching and industrial use

Technical Specifications

• Article Number: 3RT2025-1KB40
• Product Family: SIRIUS 3RT contactors
• Contactor Size: S0
• Number of Poles (main contacts): 3 (three-phase)
• Main Contact Configuration: 3 × Normally Open (NO)
• Auxiliary Contacts: 1 NO + 1 NC (instantaneous auxiliary contact)
• Rated Operational Current (Ie, AC-3 / AC-3e): 17 A
• Rated Motor Power (AC-3, 400 V): 7.5 kW
• Control Coil Voltage: 24 V DC
• Contactor Size / Frame: S0
• Terminal Type: Screw terminals (main, control, auxiliary circuits)
• Mounting Type: DIN-rail or panel / enclosure mounting (per SIRIUS 3RT standard)
• Insulation / Surge Protection: Integrated varistor for coil protection
• Suitable for PLC outputs / control wiring
• Ambient Operating Temperature Range: –25 °C … +60 °C (typical for SIRIUS 3RT series)

Compliance & Certifications

• Designed according to international low-voltage motor-contactor standards (IEC/EN 60947 series)
• Part of the modular SIRIUS 3RT system — ensures compatibility and industrial-grade build quality
• Integrated surge protection and auxiliary contact configuration makes it suitable for industrial control installations

Applications

The 3RT2025-1KB40 contactor is suitable for switching and controlling three-phase motors, pumps, fans or other inductive loads in industrial, commercial and automation settings. Typical applications include motor starters, control panels, automation control cabinets, conveyor drives, HVAC systems, and general machinery where space-saving, PLC-controlled contactors with auxiliary signalling are required. Its compact size and robust construction make it ideal for retrofit installations and modular control setups.