Siemens 3RU2126-1KB0 9–12.5A Thermal Overload Relay

Description

The Siemens 3RU2126-1KB0 is a thermal overload relay designed to provide dependable motor protection across a wide range of commercial and industrial HVAC applications. With a current setting range of 9 to 12.5 amps, this relay guards motors against damaging overload conditions, phase failure, and phase imbalance — helping extend equipment service life and reduce costly downtime.

Product Overview

Part of the Siemens 3RU2 series, the 3RU2126-1KB0 is engineered for direct mounting onto compatible Siemens 3RT2 contactors, making panel assembly straightforward and compact. Its bimetallic trip mechanism provides temperature-compensated tripping that accurately reflects true motor thermal conditions, ensuring protection even in variable ambient environments.

Key Features

• Current setting range: 9–12.5A
• Bimetallic thermal overload protection
• Integrated phase-failure sensitivity
• Manual and automatic reset modes
• Direct mounting to Siemens 3RT2 contactors (Size S0)
• TEST/RESET button for easy commissioning and maintenance
• Auxiliary contacts: 1 NC + 1 NO trip contacts
• Compact, space-saving design for panel installation

Application

Ideal for protecting single-phase and three-phase motors in HVAC motor starters, air handling units, pump panels, compressor circuits, and other commercial building automation control panels.

Specifications

• SKU / Part Number: 3RU2126-1KB0
• Brand: Siemens
• Series: 3RU2
• Current Range: 9–12.5A
• Type: Thermal Overload Relay
• Mounting: Direct-on contactor (Size S0)
• Reset: Manual / Automatic