Siemens 3RU1136-1KB0 Thermal Overload Relay

Product Description

The SIEMENS 3RU1136-1KB0 is a thermal overload relay designed to protect three-phase motors from sustained overcurrent conditions, including overload, phase loss, and phase imbalance. This device monitors motor current draw and trips the control circuit when current exceeds the preset threshold, preventing motor winding damage. It is intended for use in motor starter assemblies alongside compatible contactors in industrial and commercial electrical panels. Licensed electricians and industrial maintenance technicians are the primary installers of this class of protective device.

The 3RU1136-1KB0 is suited for motor branch circuit protection in industrial facilities, commercial buildings, and process control applications. It mounts directly to a matching contactor or independently on DIN rail, depending on the installation configuration. Typical applications include pump motors, conveyor drives, compressors, and fan systems where motor protection is required at the starter level. This relay is sized for applications requiring overload protection in the frame size corresponding to the S2 contactor class.

Key Features

• Thermal overload protection guards against sustained overcurrent and phase loss conditions
• Direct mounting to compatible S2-frame contactors for compact starter assembly
• Adjustable trip current range allows field calibration to motor nameplate FLA
• Manual and automatic reset modes supported for flexible control circuit design
• Compact footprint suits space-constrained control panel installations

Compatibility

Designed as an OEM-style thermal overload relay for use in motor starter assemblies; consult the SIEMENS 3RU1 series product documentation to confirm contactor frame and current range compatibility 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 panel before mounting or wiring the relay. Set the current adjustment dial to match the motor nameplate full-load amperage before energizing the circuit. Do not bypass the overload relay or defeat the trip mechanism under any operating condition.

Technical Specifications

• Weight: 0.688 pounds
• Length: 3.780 inches
• Width: 2.402 inches
• Height: 4.370 inches
• UPC: 75455441245

Standard Information

• Brand: SIEMENS
• Manufacturer Part Number: 3RU1136-1KB0