Siemens Overload relay for motor protection, size S0, 17-20A Part number 3RU2126-4CB0

Product Overview

Siemens overload relay 3RU2126-4CB0 is a thermal motor protection device designed to safeguard three-phase motors against overload and phase imbalance conditions. With an adjustable current setting range of 12.0 to 18.0 A and a Class 10 tripping characteristic, it provides dependable motor protection in industrial control panels. This relay supports screw connections for both main and auxiliary circuits and is intended for mounting with compatible SIRIUS contactors in Size S2 installations.

Key Features

• Thermal overload relay for motor protection
• Adjustable current range: 12.0 … 18.0 A
• Class 10 tripping characteristic
• Designed for use with Size S2 SIRIUS contactors
• Screw terminal connections for main and auxiliary circuits
• Manual, automatic and reset operation options
• Compact industrial design
• Reliable operation for industrial motor protection applications

Technical Specifications

• Article Number: 3RU2126-4CB0
• Product Family: SIRIUS overload relays
• Device Type: Thermal overload relay
• Current Setting Range: 12.0 … 18.0 A
• Tripping Class: Class 10
• Motor Protection Type: Thermal overload and phase imbalance protection
• Main Circuit Connection: Screw terminals
• Auxiliary Circuit Connection: Screw terminals
• Mounting Type: For mounting with SIRIUS Size S2 contactors
• Reset Mode: Manual, automatic or remote reset
• Operating Temperature Range: –25 °C to +60 °C
• Protection Rating: IP20 when installed in enclosure
• Housing Colour: Light grey
• Dimensions (approx.): Standard Size S2 form factor
• Weight (approx.): Industrial relay weight class

Compliance & Certifications

• Manufactured to Siemens industrial motor protection standards
• CE compliant
• RoHS compliant

Applications

The Siemens 3RU2126-4CB0 overload relay is used to protect industrial three-phase motors in control panels, motor starters and automation systems. It is typically mounted with Size S2 SIRIUS contactors to provide reliable thermal protection, overload trip functionality and reset versatility for conveyor systems, pumps, compressors and general machinery applications.