Siemens 3RT2344-1NB30 Contactor AC-1, 110A, 4-Pole, 20-33V AC/DC, Varistor, S3 Original Brand New

Overview

The Siemens 3RT2344-1NB30 is a high-performance SIRIUS power contactor designed for robust AC-1 applications, specifically for switching resistive or weakly inductive loads. This 4-pole contactor is rated for 110A at 400V and 40°C, making it ideal for disconnecting loads or integrating into power generation plants. It features a versatile 20-33V AC/DC wide-range solid-state operating mechanism with an integrated varistor for surge suppression, ensuring reliable and efficient operation. Equipped with 1 NO + 1 NC integrated auxiliary contacts and secure screw terminals, the 3RT2344-1NB30 offers dependable control and easy integration into industrial control panels. As part of the Siemens 3RT23 series, it adheres to stringent international standards like IEC 60947, guaranteeing quality and safety for your electrical systems.

Key Features & Benefit

• High Current Rating: Handles up to 110A (AC-1) at 400V/40°C, suitable for demanding non-inductive and resistive load switching.
• 4-Pole Design: Provides comprehensive control for multi-phase applications and diverse switching requirements.
• Wide Range AC/DC Control: Flexible 20-33V AC/DC operating mechanism allows for universal application and simplified inventory.
• Integrated Varistor: Built-in surge suppression protects the coil and extends the contactor’s lifespan by damping opening surges.
• Auxiliary Contacts: Includes 1 NO (normally open) and 1 NC (normally closed) auxiliary contacts for enhanced control circuit functionality and status indication.
• Robust Screw Terminals: Ensures secure and reliable electrical connections for main, auxiliary, and control circuits.
• Compact Size S3: Optimized dimensions for efficient space utilization within control cabinets.
• High Contact Reliability: Auxiliary contacts are designed for reliable switching even at low voltages (≤ 110V) and currents (≤ 100mA), making them ideal for solid-state circuits.
• Standards Compliance: Manufactured in accordance with IEC 60947-1, IEC 60947-4-1, and IEC 60947-5-1, ensuring global compatibility and safety.
• Expandable Functionality: Can be easily expanded with additional auxiliary switches (sold separately) for increased control flexibility.

Function

• AC-1 Switching: Primarily designed for switching of resistive, non-inductive, or weakly inductive loads.
• Load Disconnection: Effectively disconnects various loads from the electrical grid.
• Power Generation Integration: Suitable for transfer switching and integrating power generation plants.
• Control Circuit Operation: Enables activation and deactivation of industrial machinery and processes via its control supply voltage.
• Auxiliary Signaling: Provides feedback on contactor status through its integrated auxiliary contacts for interlocking and signaling purposes.
• Overvoltage Protection: The integrated varistor protects the coil from damaging voltage spikes.

Protection and Installation Guidelines:

• Short-circuit & Overload Protection: All connections (main, auxiliary, control supply) must be protected against overload and short circuits using appropriate measures. Refer to the technical product data sheet, Digital Configuration Manual for load feeders, and relevant standards for detailed guidance.
• Overvoltage Protection (Control Supply): The integrated varistor provides protection. For other 3RT23 contactors without integrated damping, external surge suppressors (RC elements, varistors, diodes) can be retrofitted.
• Connection Methods:
  • Main Circuit: Screw terminals with box terminal. Direct connection to connecting bar possible with cable lugs when the box terminal is removed.
  • Auxiliary & Control Circuit: Screw terminals.
• Motor Protection: For motor-driven loads (AC-3), 3RU2 thermal overload relays or 3RB3 electronic overload relays can be mounted on 3RT23 contactors.
• Contact Reliability: Auxiliary contacts are highly reliable, even for solid-state circuits with currents $\ge$ 1 mA at voltages of 17V and higher.

Maintenance and Accessories:

• Coil Replacement: The solenoid coil can be replaced on 3RT23 contactors.
• Contact Replacement: Only the contacts for 3RT233 contactors can be replaced. (Note: Not possible for 3RT13 contactors).
• Auxiliary Switch Expansion: Basic units can be expanded with additional auxiliary switches (refer to “Auxiliary switches, instantaneous → Overview” for details).
• Compatible Accessories: Refer to “Accessories and spare parts for SIRIUS 3RT2 contactors and SIRIUS 3RH2 contactor relays” for a full list of compatible accessories and spare parts.

Application

• Switching of weak or non-inductive loads (AC-1)
• Disconnecting loads or power generation plants from the grid
• Transfer switching applications
• General industrial control circuits

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