Schneider Thermal Overload Relay LRD07

Schneider Electric LRD07 Thermal Overload Relay — Precision Protection for Small 3-Phase Motors

The Schneider Thermal Overload Relay LRD07 is a compact and dependable motor protection device from Schneider Electric’s TeSys LRD series, engineered to safeguard three-phase motors against prolonged overcurrent, phase loss, and unbalanced load conditions. Designed for industrial and commercial electrical systems, this relay forms a critical part of motor starter assemblies where reliable thermal protection is needed.

🔌 What Is the Schneider LRD07 Thermal Overload Relay?

The LRD07 is a three-pole thermal overload relay with an adjustable current protection range of 1.6 – 2.5 A, making it ideal for protecting small three-phase motors (up to approximately ~0.75 kW at 400 V AC) in control panels and automated systems. It continuously monitors current in all three phases and disconnects power if prolonged overload or abnormal phase conditions occur, helping prevent motor winding overheating and damage.

The relay features a Class 10A trip characteristic, which balances tolerance for normal motor start-up inrush currents with reliable tripping on sustained overloads, conforming to IEC 60947-4-1 standards.

🛠️ Key Features & Benefits

• Adjustable Current Range (1.6 – 2.5 A) — Tailor the overload setting to match the motor’s full-load current for precise protection.

• Three-Pole Thermal Monitoring — Ensures balanced protection across all three phases and detects phase loss or unbalanced conditions.

• Class 10A Trip Characteristic — Provides dependable overload response while tolerating typical motor start-up surges.

• Manual/Automatic Reset Options — Choose reset behaviour based on application needs — manual after a fault or automatic once conditions normalise.

• Auxiliary Contacts (1NO + 1NC) — Allows fault signalling to control panels, PLCs, or automation systems for enhanced safety and monitoring.

• Secure Screw-Clamp Terminals — Reliable, vibration-resistant electrical connections for both power and control wiring.

• Compact Industrial Build — Designed to mount directly under compatible Schneider contactors (LC1D09 through LC1D32) or be panel mounted.

• Phase Loss Sensitivity — Trips promptly when phase irregularities occur, reducing motor stress and preventing damage.

⚙️ Why Use the LRD07 Overload Relay?

Thermal overload relays like the LRD07 are essential in protecting motors against conditions that can cause overheating, insulation breakdown, and unplanned breakdowns. The LRD07 helps you:

• Prevent costly motor damage by detecting sustained overcurrent early

• Minimise downtime with quick fault detection and reliable tripping

• Enhance electrical safety with phase loss and imbalance protection

• Extend motor and system lifespan with dependable thermal safeguards

• Integrate seamlessly with Schneider contactors for compact, efficient motor starter assemblies

This makes the LRD07 ideal for panel builders, engineers, and maintenance teams working with small motor control applications.

📌 Typical Applications

The Schneider Thermal Overload Relay LRD07 is perfect for:

• Motor starter assemblies in industrial control panels

• Pumps, small compressors & fans

• Conveyor and material handling systems

• HVAC motor control and ventilation drives

• Automated production equipment and machinery

Its compact design and adjustable current range ensure reliable motor protection in a variety of three-phase electrical systems.