Siemens 3RU21261GB0 4.5-6.3A Thermal Overload Relay

Siemens 3RU21261GB0 4.5-6.3A Thermal Overload Relay

The 3RU21261GB0 is a compact, three-phase thermal overload relay designed for motor protection. It’s optimized to mount directly to Siemens S0-size contactors, making it a space-saving choice for control panels.

Key Specifications:

• Current Range: Adjustable from 4.5 to 6.3 A

• Trip Class: Class 10 (trip in around 10 seconds under overload)

• Mounting Style: Direct contactor mounting (S0 frame) with screw terminals 

• Enclosure Protection: IP20 rated, suitable for panel installation 

• Operating Temperature: −20 to +70 °C (some sources list −40 °C to +70 °C) 

• Dimensions: 85 × 45 × 85 mm (H × W × D), roughly 0.408 lb weight 

Core Features:

• Motor & Phase Protection: Guards against motor overload and phase loss

• Reset Options: Manual or automatic reset with visible trip indicator, test slide, and STOP button

• Reliable Design: Class 10 trip curve, IEC/UL-approved, optimized for 3RT contactors 

• Global Certifications: UL, CSA, IEC, CE, EAC, and more

Benefits at a Glance:

• Protects motors from overheating and phase imbalance

• Easy to mount and wire into Siemens contactors or panels

• Small footprint for compact control cabinets

• Simple operation: visible trip signal and intuitive reset/testing

• Widely certified and globally deployable

Ideal Applications:

• Motor starter assemblies

• HVAC systems

• Pumps, fans, compressors

• General-purpose 3-phase motor protection