Siemens Thermal Overload Relay 70–90 A, Class 10, Size S3, Contactor Mounting – 3RU2146-4LB00-8K

Product Description

The Siemens 3RU2146-4LB00-8K is a genuine SIRIUS 3RU2 Thermal Overload Relay designed to provide reliable overload and phase-failure protection for three-phase induction motors. With an adjustable current range of 70–90 A, Class 10 tripping characteristic, and Size S3 frame, this overload relay is ideal for protecting industrial motors against overheating and excessive current. It is designed for direct contactor mounting, creating a compact motor starter assembly while reducing panel space and simplifying installation. The relay features screw terminals for both the main and auxiliary circuits and supports manual and automatic reset for flexible operation.

The 3RU2146-4LB00-8K is widely used in Motor Control Centers (MCCs), industrial control panels, OEM machinery, pumps, compressors, conveyor systems, HVAC equipment, water treatment plants, and manufacturing industries. Its temperature-compensated thermal protection ensures accurate tripping during overload conditions while preventing nuisance trips caused by ambient temperature changes. This helps extend motor life, reduce downtime, and improve overall system reliability.

At SB Smart, Faridabad, we supply 100% genuine Siemens SIRIUS Thermal Overload Relays, Contactors, Motor Protection Circuit Breakers (MPCB), Soft Starters, MCCBs, MCBs, PLCs, HMIs, VFDs, and Industrial Automation Products at competitive prices. We offer GST invoices, expert technical support, bulk order pricing, secure packaging, and fast delivery across Faridabad, Delhi NCR, Mumbai, Pune, Bengaluru, Chennai, Hyderabad, Ahmedabad, Kolkata, and all major cities in India.

Key Features

• Genuine Siemens SIRIUS 3RU2 Thermal Overload Relay
• Model: 3RU2146-4LB00-8K
• Adjustable Current Range: 70–90 A
• Class 10 Tripping Characteristic
• Size S3
• Direct Contactor Mounting
• Main Circuit: Screw Terminal
• Auxiliary Circuit: Screw Terminal
• Manual and Automatic Reset
• Phase Failure Sensitive Protection
• Temperature-Compensated Operation
• Compact and Rugged Industrial Design
• Long Service Life

Applications

• Motor Control Centers (MCC)
• Industrial Control Panels
• OEM Machinery
• Pumps and Compressors
• Conveyor Systems
• HVAC Systems
• Water Treatment Plants
• Manufacturing Industries
• Process Automation
• Industrial Motor Protection

Benefits

• Protects motors from overload and phase-failure conditions
• Extends motor service life
• Minimizes unexpected downtime
• Space-saving contactor-mounted design
• Quick and easy installation
• Accurate Class 10 thermal protection
• Reliable performance in demanding industrial environments
• Genuine Siemens quality for long-term reliability

Frequently Asked Questions (FAQs)

Q1. What is the Siemens 3RU2146-4LB00-8K used for?

The 3RU2146-4LB00-8K is a thermal overload relay used to protect three-phase motors against overload and phase-failure. It is designed for direct mounting on Siemens S3 contactors.

Q2. What is the adjustable current range?

The relay offers an adjustable overload setting from 70 A to 90 A, suitable for a wide range of industrial motor applications.

Q3. What type of mounting and terminals does it use?

It is designed for contactor mounting and features screw terminals for both the main and auxiliary circuits.

Q4. Does this overload relay support manual and automatic reset?

Yes. The 3RU2146-4LB00-8K supports both manual and automatic reset, providing flexibility for industrial motor control applications.

Q5. Why buy Siemens 3RU2146-4LB00-8K from SB Smart Faridabad?

SB Smart, Faridabad supplies 100% genuine Siemens industrial automation products with competitive pricing, GST invoices, expert technical support, bulk order assistance, and fast delivery across India for OEMs, panel builders, contractors, and industrial customers.