Siemens 3RU21264FB1 Overload Relay Class 10

Product Description

The SIEMENS 3RU21264FB1 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 contactors or can be used in a stand-alone panel configuration, making it a standard component in motor starter assemblies. Class 10 trip response means the relay will interrupt the circuit within 10 seconds at 7.2 times the set current, providing fast protection for motors with lower inertia loads. Licensed electricians and industrial control technicians are the primary installers of this device.

This overload relay is suited for use in commercial and industrial motor control applications including pump panels, conveyor drives, fan starters, and compressor control panels. It is typically installed as part of a combination motor starter in MCC buckets or standalone enclosures. The compact footprint allows integration into tight panel layouts without sacrificing accessibility to the adjustment dial.

Key Features

• Class 10 trip characteristic for fast motor protection on low-inertia loads
• Direct mounting compatibility with Siemens contactor product families
• Adjustable current setting dial for field calibration to motor FLA
• Phase-failure sensitivity to detect single-phasing conditions
• Compact form factor suited for dense panel builds

Compatibility

Designed as an OEM-style overload relay for use in Siemens motor starter assemblies. No specific compatible model numbers were provided in the product data.

Installation Notes

Installation should be performed by a licensed electrician in accordance with NFPA 70 (NEC) Article 430 requirements for motor branch-circuit and overload protection. De-energize and lock out the panel before mounting, wiring, or adjusting the relay. Set the current adjustment dial to match the motor nameplate full-load amperage after installation and before commissioning. Do not bypass or tape over the manual reset mechanism.

Technical Specifications

• Trip Class: Class 10
• Length: 4.567 inches
• Width: 1.929 inches
• Height: 4.016 inches
• Weight: 0.553 pounds
• UPC: 66264391943
• Quantity per Pack: 1

Standard Information

• Brand: SIEMENS
• Manufacturer Part Number: 3RU21264FB1