Schneider Thermal Overload Relay LRD3365

Schneider LRD3365 Thermal Overload Relay — Heavy-Duty Motor Protection for Industrial Systems

The Schneider Thermal Overload Relay LRD3365 is a professional-grade motor protection relay from Schneider Electric’s TeSys LRD series, designed to safeguard medium-to-large three-phase motors in industrial and commercial applications. With a broad adjustable current range and reliable trip mechanism, this overload relay helps protect motors from overheating, phase loss, and sustained overcurrent — enhancing system safety, performance, and equipment longevity.

🔌 What Is the Schneider LRD3365 Thermal Overload Relay?

The Schneider LRD3365 is a three-pole thermal overload relay built to complement heavy-duty contactors in motor starter assemblies. It monitors current flowing through each phase and trips the circuit when prolonged overload conditions occur, preventing severe motor damage. With an adjustable thermal range from 80 A to 104 A, this relay is suitable for protecting larger motors up to ~45 kW at 400 V AC.

Its Class 10A trip characteristic delivers a balanced response — tolerating short start-up currents while quickly reacting to sustained overloads. Combined with phase imbalance and phase loss sensitivity, LRD3365 offers dependable protection exactly where it’s most needed in industrial control systems.

🛠️ Key Features & Benefits

• Wide Adjustable Current Range (80 – 104 A) — Fine-tune the relay to match the full-load current (FLC) of larger three-phase motors for precision protection.

• Class 10A Trip Curve — Provides a responsive yet tolerant overload trip profile suitable for high-output industrial motors.

• Three-Pole Thermal Protection — Continuously monitors all three phases, disconnecting power before harmful thermal stress occurs.

• Phase Loss & Unbalance Detection — Enhances safety by tripping when phase issues are detected, preventing motor damage.

• Manual/Automatic Reset Options — Offers flexible control after a trip, helping minimise downtime.

• 1NO + 1NC Auxiliary Contacts — Easy integration with control panels, alarms, and automation circuits for enhanced system feedback.

• Screw-Clamp Terminals — Secure and vibration-resistant wiring for dependable connections.

• Compact, Panel-Friendly Build — Designed for direct mounting beneath compatible contactors (e.g., LC1D80/LC1D95) or on DIN rail.

🧰 Industrial & Commercial Use Cases

The LRD3365 thermal overload relay is ideal for a variety of demanding protection tasks in industrial electrical systems:

• Motor Starter Assemblies — Safeguards large three-phase motors against overload damage.

• Pumps & Compressors — Protects continuous-duty motors in industrial pumping systems.

• HVAC & Ventilation Motors — Reliable protection for high-capacity fans and blowers.

• Conveyor & Material Handling Systems — Guards motors in automation and manufacturing lines.

• Industrial Machinery Panels — Ensures safe long-term operation within electrical control cabinets.

By preventing thermal damage, phase imbalance effects, and extended overcurrent conditions, the LRD3365 helps minimise unexpected downtime and reduce maintenance costs — crucial factors in industrial environments.