Schneider Electric LR3D21 Thermal Iec Overload Relay

Product Description

The SCHNEIDER ELECTRIC LR3D21 is a thermal IEC overload relay rated for 12 to 18 amps at up to 690 volts AC. It provides motor protection by sensing excess current draw and tripping the circuit before thermal damage occurs. Designed to Trip Class 10A, it responds quickly to overload conditions typical in motor-control applications. Licensed electricians and industrial maintenance technicians install this relay as part of a contactor-based motor starter assembly. The compact form factor measures 3.5 inches in length, 3.1 inches in width, and 2 inches in height, and the unit weighs 0.33 pounds.

The LR3D21 is used in residential and light commercial motor control applications where IEC-standard protection is required. It mounts directly to compatible contactors and is specified for use with the LC1D18 and LC1D38 contactors. Typical install scenarios include pumps, fans, compressors, and conveyor drives where overload protection is a code requirement. Its adjustable current range of 12 to 18 amps makes it suitable for a range of motor sizes within that band.

Key Features

• Adjustable current range: 12 to 18 amps for flexible motor protection
• 690 VAC voltage rating supports a wide range of IEC motor-control applications
• Trip Class 10A for fast response to overload conditions
• Direct-mount design for compatible LC1D-series contactors
• Compact footprint: 3.5 x 3.1 x 2 inches for tight panel installations
• Thermal sensing method for reliable, proven overload detection

Compatibility

Designed for direct use with LC1D18 and LC1D38 contactors as stated by the manufacturer.

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 circuit before mounting or wiring the relay. The relay mounts directly onto the contactor without additional hardware; verify the contactor model is compatible before installation. Do not exceed the rated voltage or current range during operation.