Siemens 3RT2327-2BB40 SIRIUS Contactor AC-1, 50A, 4-Pole, 24V DC, Spring-Loaded, Size S0 Original Brand New

Overview

The Siemens 3RT2327-2BB40 is a high-performance SIRIUS 3RT23 series power contactor engineered for reliable switching of AC-1 (non-inductive or weakly inductive) loads. With a robust 50 A current rating at 400 V / 40 °C, this 4-pole contactor is perfectly suited for applications such as disconnecting loads from the grid, controlling power generation plants, and transfer switching. Its 24 V DC operating mechanism ensures efficient and precise control, while the integrated 1 normally open (NO) and 1 normally closed (NC) auxiliary contacts provide essential feedback and control options.

The innovative spring-loaded terminals facilitate quick, secure, and vibration-resistant wiring, making installation and maintenance straightforward. Conforming to international standards like IEC 60947, the 3RT2327-2BB40 delivers exceptional contact reliability and electromagnetic compatibility in industrial environments.

Benefit

• Reliable AC-1 Switching: Specifically designed for efficient and safe switching of non-inductive or weakly inductive loads, ensuring stable operation.
• Space-Saving Design: Compact Size S0 footprint optimizes panel space.
• Fast & Secure Wiring: Spring-loaded terminals offer quick, tool-free, and highly reliable connections, reducing installation time and increasing operational uptime.
• Integrated Auxiliary Contacts: Comes standard with 1 NO + 1 NC contacts, providing immediate control and status feedback without requiring additional modules.
• Enhanced Safety: Designed with comprehensive protection features for main, auxiliary, and control circuits against short-circuits, overloads, and overvoltage when properly configured.
• High Contact Reliability: Auxiliary contacts are optimized for low voltages and currents, making them ideal for sensitive electronic circuits.
• Broad Application Versatility: Suitable for diverse applications including load disconnection, power generation plant control, and transfer switching.
• Standards Compliant: Meets rigorous international standards, including IEC 60947-1, IEC 60947-4-1, and IEC 60947-5-1, guaranteeing quality and safety.

Function

• Four-pole Switching: Capable of switching four independent circuits simultaneously, ideal for multi-phase non-inductive loads.
• Load Control (AC-1): Efficiently makes and breaks circuits for resistive loads, heating elements, and general non-motor loads.
• Disconnecting Loads: Provides a reliable means to isolate electrical loads or entire power generation systems from the main grid.
• Transfer Switching: Facilitates the smooth and safe transfer between different power sources or load configurations.
• Auxiliary Contact Signaling: The integrated 1 NO + 1 NC auxiliary contacts provide status indication (e.g., contactor ON/OFF) for interlocking or control circuits.
• DC Coil Operation: Utilizes a 24 V DC control supply, offering precise and consistent operation.

Standards Compliance:

The Siemens 3RT2327-2BB40 contactor adheres to the following key international standards, ensuring high quality, safety, and performance:

• IEC 60947-1: General requirements for low-voltage switchgear and controlgear.
• IEC 60947-4-1: Contactors and motor-starters.
• IEC 60947-5-1: Control circuit devices and switching elements (specifically for auxiliary switches).

Protection of Device Connections:

To ensure safe and reliable operation, all connections to the 3RT2327-2BB40 contactor must be adequately protected against short circuits and overloads.

• Main Connections: For detailed information on protecting a standalone contactor, refer to the technical product data sheet. For device combinations (e.g., with overload relays or circuit breakers as motor feeders), consult the Siemens Digital and physical Configuration Manuals for load feeders.
• Auxiliary Connections: Information regarding the protection of auxiliary contacts is available in the technical product data sheet.
• Control Supply Voltage Connections: Protection must align with relevant standards for control panel configuration, including cable dimensioning. Potential protection methods include current-limiting power supplies, considering the contactor’s load characteristics (inrush current, switch-on/holding power). If other switching elements are present, their short-circuit protection requirements must also be considered. For further guidance on selecting suitable protection devices like miniature or circuit breakers, refer to Siemens’ “Control panel tip – Selecting and dimensioning suitable power supplies quickly and reliably.”

Overvoltage Protection (Control Supply):

The 3RT2327-2BB40 can be retrofitted with surge suppressors (RC elements, varistors, diodes, or diode assemblies) to dampen opening surges in the coil, which must be ordered separately as accessories. Note that damping increases the contactor’s break times and the delay times of NO and NC contacts. Detailed information on this influence is available in the Equipment Manual.

Connection Methods:

• Main Circuit: This 3RT232 contactor utilizes convenient spring-loaded terminals, which also feature a plug-in design for easy device connection.
• Auxiliary and Control Circuit: Connections are made via reliable screw terminals.

Electromagnetic Compatibility (EMC):

The 3RT2327-2BB40 contactor meets the requirements for environment category A, ensuring its robust performance in industrial settings. When used in environments with frequency converters, specific configuration notes in the Equipment Manual must be observed.

Contact Reliability of Auxiliary Contacts:

For switching low voltages (≤ 110 V) and currents (≤ 100 mA), the auxiliary contacts of the 3RT23 series are highly recommended due to their superior contact reliability. These contacts are particularly effective for solid-state circuits operating at currents ≥ 1 mA and voltages of 17 V or higher.

Motor Protection Integration:

While primarily for AC-1 loads, the 3RT23 contactors can be equipped with Siemens 3RU2 thermal overload relays or 3RB3 electronic overload relays for protection against motor overload if used in combined applications.

Operating Mechanism:

The 3RT2327-2BB40 features a conventional DC operating mechanism, controlled via the A1-A2 control supply voltage connection. Refer to the technical product data sheet for specific operating ranges.

Maintenance and Expandability:

• Solenoid Coil: The solenoid coil of the 3RT2327-2BB40 can be replaced, extending the lifespan of the unit.
• Auxiliary Contacts: The basic unit includes integrated 1 NO + 1 NC auxiliary contacts. The 3RT2327-2BB40 can be expanded with additional auxiliary switches, provided the permissible configuration is observed. Detailed information on fitting auxiliary switches can be found in the “Auxiliary switches, instantaneous → Overview” documentation.

Accessories and Spare Parts:

A wide range of accessories and spare parts are available for the SIRIUS 3RT2 contactors, including surge suppressors, additional auxiliary switches, and more. Refer to the “Accessories and spare parts for SIRIUS 3RT2 contactors and SIRIUS 3RH2 contactor relays” documentation for a complete list.

Application

The Siemens 3RT2327-2BB40 contactor is ideal for a variety of industrial and commercial applications, including:

• Four-pole switching of weak or non-inductive loads (AC-1)
• Disconnecting electrical loads from the grid
• Isolating power generation plants
• Implementing transfer switching operations in power distribution systems

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