Schneider Electric (Square D) LRD350 37-50A Overload Relay

Description

The Schneider Electric (Square D) LRD350 is a thermal overload relay designed to provide reliable motor protection across a wide range of HVAC and industrial applications. Part of the industry-trusted TeSys D series, this overload relay mounts directly onto compatible TeSys D contactors for a compact, integrated motor starter assembly.

Overview

The LRD350 protects three-phase motors from the damaging effects of overload, phase loss, and phase imbalance. Its bimetallic thermal sensing technology responds to sustained overcurrent conditions, tripping the relay before motor windings can be damaged. The adjustable current range of 37–50A makes it suitable for a broad selection of motor sizes commonly found in commercial HVAC equipment, pumps, fans, and compressor circuits.

Key Features

• Adjustable current setting range: 37–50A
• Direct mounting to TeSys D series contactors (LC1D and LC1F families)
• Bimetallic thermal overload protection
• Phase loss and phase imbalance detection
• Manual and automatic reset modes
• Integrated test and reset button
• Normally open (NO) and normally closed (NC) auxiliary contacts for control circuit integration
• Class 10 trip class for standard motor protection
• Ambient temperature compensation for consistent performance

Specifications

• Brand: Schneider Electric (Square D)
• Model / SKU: LRD350
• Current Range: 37–50A
• Series: TeSys D
• Trip Class: Class 10
• Reset Mode: Manual / Automatic
• Auxiliary Contacts: 1 NO + 1 NC
• Mounting: Direct onto TeSys D contactors

Applications

• Commercial HVAC motor starters
• Chiller and compressor control panels
• Pump and fan motor protection
• Air handling unit (AHU) electrical panels
• Industrial motor control centers (MCCs)

Why Choose the LRD350?

Schneider Electric’s TeSys D overload relays are globally recognized for their reliability, ease of installation, and long service life. The LRD350’s direct-mount design eliminates the need for separate wiring between the contactor and overload relay, reducing panel complexity and potential failure points. Whether you’re building a new motor starter assembly or replacing a worn overload relay in the field, the LRD350 delivers proven protection you can count on.