Siemens Power contactor, screw, size S2, 2NO + 2NC, 400V / 18.5kW Part number 3RT2535-1NB30

Product Overview

The Siemens 3RT2535-1NB30 is a motor starter (contactor) from the SIRIUS 3RT2 series. It is designed for switching and controlling three-phase motors, providing reliable electrical connection/disconnection, and is suitable for industrial automation, motor control panels, and machinery applications.

Key Features

• Three-pole AC contactor for 3-phase motors and loads
• Coil voltage and contact configuration optimized for robust motor switching
• High switching capacity for industrial motor control applications
• Compact design — suitable for control cabinets and motor control centres (MCCs)
• Standard screw terminal connections for secure wiring
• Can be combined with overload relays and auxiliary contacts for full motor starter functionality

Technical Specifications

• Article Number: 3RT2535-1NB30
• Product Series: SIRIUS 3RT2 contactor
• Poles: 3-pole
• Utilisation Category (AC-3): Suitable for switching motors under normal starting/stopping loads
• Rated Operational Current (Ie): 9 A at 400 V AC (AC-3) — suitable for light to medium motors
• Rated Insulation Voltage (Ui): 400 V AC / 690 V AC depending on configuration
• Terminal Type: Screw terminals (line and load sides)
• Mechanical Durability: Designed for many switching cycles typical in industrial usage
• Mounting: DIN-rail or panel mounting as per standard contactor installation practice

Compliance & Standards

• Part of the Siemens SIRIUS 3RT2 motor-contactor family
• Designed and manufactured to meet IEC/EN standards for low-voltage motor switching
• Suitable for industrial automation, machinery, and motor control installations conforming to safety and reliability norms

Applications

The 3RT2535-1NB30 contactor is ideal for switching and controlling small to medium three-phase motors — such as in pumps, fans, conveyors, compressors, and general machinery. It is commonly incorporated into motor control panels, automation cabinets, and machine starter assemblies. When paired with a compatible overload relay and auxiliary contacts, it offers full motor starter functionality for industrial automation or mechanical systems.