Siemens 3RU21161DC0 Overload Relay Class 10

Product Description

The SIEMENS 3RU21161DC0 is a Class 10 thermal overload relay designed to protect three-phase motors from overload and phase-failure conditions. It mounts directly to compatible Siemens contactor assemblies, making it a compact and reliable component in motor starter circuits. Class 10 trip response means the relay trips within 10 seconds at 7.2 times the set current, providing fast protection for motors with low starting inertia. Licensed electricians and industrial maintenance technicians typically install this relay in motor control panels and combination starter assemblies.

This overload relay is suited for residential, commercial, and light industrial motor control applications. It is used in motor starter assemblies where direct-on-line starting is employed and where reliable overload protection is required. Common installation scenarios include pump motors, fan motors, and conveyor drives controlled through contactor-based starters. Its compact footprint allows integration into existing panel layouts without significant modification.

Key Features

• Class 10 trip characteristic provides fast overload protection for low-inertia motor loads
• Designed for direct mounting to compatible Siemens contactor assemblies for a compact starter build
• Thermal overload detection guards against motor damage from sustained overcurrent and phase loss
• Compact dimensions of 4.016 inches x 1.929 inches x 3.307 inches suit tight panel installations
• Lightweight construction at 0.379 pounds simplifies handling during installation

Compatibility

Designed as an OEM-style overload relay for use with compatible Siemens contactor-based motor starter assemblies. Verify contactor frame size and current setting range against the application requirements before installation.

Installation Notes

Installation should be performed by a licensed electrician in accordance with the NEC and applicable local codes. De-energize and lock out the control panel before installing or adjusting the relay. Set the current adjustment dial to match the full-load ampere rating shown on the motor nameplate. Do not bypass or defeat the overload relay reset mechanism during commissioning.