The Siemens 3RU2126-1CB00-8K is a compact and reliable thermal overload relay from the trusted SIRIUS 3RU2 Series, engineered to provide dependable protection for three-phase motors against overload conditions, phase failure, and excessive current draw. Featuring an adjustable current setting range of 1.8–2.5 A, Class 10 tripping characteristics, and compatibility with Size S0 Siemens contactors, this relay is ideally suited for industrial motor control systems, automation equipment, and compact motor starter assemblies. Siemens SIRIUS 3RU2 relays are specifically designed for current-dependent motor protection and direct contactor mounting applications.
The relay uses Siemens' proven thermal overload protection principle with inverse-time delayed tripping. This helps prevent motor overheating, winding damage, insulation deterioration, and costly downtime while allowing normal motor starting currents to pass without nuisance tripping. Integrated phase-failure sensitivity further enhances motor protection and operational reliability.
The Variant CB008K offers an adjustable overload release setting of 1.8–2.5 A, making it suitable for protecting small three-phase motors used in pumps, fans, conveyors, compressors, HVAC systems, packaging machinery, machine tools, and industrial automation equipment. Its compact S0 frame size enables efficient installation in motor control centers, OEM machinery, switchboards, and industrial control panels. Based on the Siemens 3RU2126 S0 overload relay range, the CB variant is positioned below the 2.2–3.2 A DB variant and is intended for lower-rated motor applications.
The relay includes 1 Normally Open (NO) and 1 Normally Closed (NC) auxiliary contact for signaling, trip indication, and control circuit integration. It supports both manual and automatic reset modes and features screw-type terminals for secure wiring and simplified maintenance.
Manufactured according to Siemens' stringent quality standards, the 3RU2126-1CB00-8K delivers long service life, reliable motor protection, and dependable performance in demanding industrial environments.
| Specification | Details |
|---|---|
| Product Name | Thermal Overload Relay |
| Part Number | 3RU2126-1CB00-8K |
| SKU | 3RU2126-1CB00-8K |
| Brand | Siemens |
| Product Family | SIRIUS 3RU2 |
| Product Type | Motor Protection Relay |
| Variant | CB008K |
| Current Setting Range | 1.8–2.5 A |
| Relay Size | S0 |
| Trip Class | Class 10 |
| Mounting Type | Direct Contactor Mounting |
| Operating Principle | Thermal |
| Main Circuit Connection | Screw Terminal |
| Auxiliary Circuit Connection | Screw Terminal |
| Auxiliary Contacts | 1 NO + 1 NC |
| Reset Type | Manual / Automatic |
| Rated Insulation Voltage | Up to 690 V AC |
| Number of Main Poles | 3 |
| Protection Features | Overload & Phase Failure Protection |
| Application | Industrial Motor Protection |
| Manufacturer | Siemens |
No reviews yet.