Siemens 3RT2337-1NB30 SIRIUS 3RT2 Contactor, AC-1, 110A, 4-Pole, 20-33V AC/DC, Varistor, S2 Size Original Brand New

Overview

The Siemens 3RT2337-1NB30 is a high-performance SIRIUS 3RT2 series contactor, specifically designed for switching of four-pole weak or non-inductive loads (AC-1 applications). Engineered for reliability and versatility, this Size S2 contactor is rated for 110 A at 400 V / 40 °C. It features a wide-range 20-33 V AC/DC control supply voltage with an integrated varistor for surge suppression, ensuring robust operation and extended coil life. Equipped with 1 normally open (NO) and 1 normally closed (NC) auxiliary contacts and secure screw terminals, the 3RT2337-1NB30 offers dependable control and easy integration into various industrial automation and power distribution systems.

Benefit

• Reliable Performance: Built to IEC 60947 standards, ensuring consistent and safe operation.
• Enhanced Protection: Integrated varistor protects the control coil from overvoltage, extending the contactor’s lifespan.
• Versatile Control: Wide-range AC/DC control voltage allows for flexible integration into various control circuits.
• Easy Integration: Screw terminals provide secure and straightforward wiring.
• Space-Saving Design: Compact S2 size for efficient panel layout.
• Comprehensive Functionality: Includes essential auxiliary contacts for signaling and interlocking.
• Broad Application: Ideal for disconnecting loads, power generation plants, and transfer switching.

Function

• Main Circuit Switching: The primary function is to switch four-pole AC-1 loads, such as resistive heaters, lighting circuits, and non-inductive power distribution applications.
• Load Disconnection: Capable of disconnecting various loads from the grid.
• Power Generation Plant Integration: Suitable for use in systems involving power generation.
• Transfer Switching: Can be utilized in transfer switching applications.
• Auxiliary Contact Operation: The integrated 1 NO + 1 NC auxiliary contacts provide feedback on the contactor’s status and enable interlocking functionalities within control circuits.
• Coil Protection: The integrated varistor effectively dampens opening surges in the coil, protecting it from transient overvoltages.

Standard

The Siemens 3RT2337-1NB30 contactor conforms to stringent international standards, including:

• IEC 60947‑1: General rules for low-voltage switchgear and controlgear
• IEC 60947‑4‑1: Contactors and motor-starters – Electromechanical contactors and motor-starters
• IEC 60947‑5‑1: Control circuit devices and switching elements – Electromechanical control circuit devices (for auxiliary switches)

Protection of Connections:

• Short-circuit and Overload Protection of Main Connections: Requires appropriate external protection. Refer to the technical product data sheet for free-standing contactor protection. For device combinations (contactor with overload relay or circuit breaker), consult the Digital or standard Configuration Manuals for load feeders.
• Short-circuit and Overload Protection of Auxiliary Connections: Refer to the technical product data sheet for specific information.
• Short-circuit and Overload Protection of Control Supply Voltage: Consideration of relevant standards for control panel configuration and components is crucial. Solutions include power supplies with current-limiting functions and suitable protection devices like miniature or circuit breakers.
• Protection against Overvoltage at Control Supply Voltage: The 3RT2337-1NB30 features an integrated varistor for damping opening surges, providing built-in protection. Note that damping can influence break and delay times; refer to the Equipment Manual for details.

Connection Methods:

• Main Circuit: Screw terminals with box terminal design. Direct connection with cable lugs is possible when the box terminal is removed.
• Auxiliary and Control Circuit: Screw terminals.

Electromagnetic Compatibility (EMC): The contactor meets the requirements for environment category A. When used with frequency converters, specific configuration notes from the Equipment Manual must be observed.

Contact Reliability of Auxiliary Contacts: The auxiliary contacts are designed for high contact reliability, particularly suitable for switching low voltages (≤ 110 V) and low currents (≤ 100 mA), as well as solid-state circuits with currents ≥ 1 mA at voltages ≥ 17 V.

Motor Protection (Relevant for Motor Applications): For overload protection, 3RU2 thermal overload relays or 3RB3 electronic overload relays can be mounted directly onto 3RT23 contactors.

Operating Mechanism Type: This 3RT23 contactor version features a wide-range solid-state operating mechanism, allowing for universal AC or DC actuation (20-33 V AC/DC). Control is via connections A1-A2.

Maintenance & Expansion:

• Solenoid Coil Replacement: The solenoid coil is replaceable.
• Auxiliary Contact Expansion: Basic units can be expanded with additional auxiliary switches, provided the permissible configuration is observed. For detailed information, see “Auxiliary switches, instantaneous → Overview.”

Accessories and Spare Parts: A wide range of accessories and spare parts are available for SIRIUS 3RT2 contactors, including additional auxiliary switches, surge suppressors (for non-integrated versions), and connection components. Refer to the “Accessories and spare parts for SIRIUS 3RT2 contactors” section on Turll for ordering data.

Application

The Siemens 3RT2337-1NB30 contactor is ideal for:

• Four-pole switching of weak or non-inductive loads (AC-1)
• Disconnecting various loads or power generation plants from the grid
• Transfer switching applications in industrial and commercial settings.

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