Schneider Thermal Overload Relay LRD3363

Schneider Thermal Overload Relay LRD3363 — Heavy-Duty Thermal Motor Protection

The Schneider Thermal Overload Relay LRD3363 is a high-performance motor protection device designed to safeguard medium-to-large three-phase motors against prolonged overcurrent, phase loss, and unbalanced load conditions. Part of Schneider Electric’s TeSys LRD series, this thermal overload relay delivers dependable protection with adjustable current settings — ideal for industrial and commercial electrical systems where reliable motor operation and safety are essential.

🔌 What Is the Schneider LRD3363 Thermal Overload Relay?

The LRD3363 thermal overload relay is a three-pole overload protection unit engineered for use with Schneider TeSys contactors (e.g., LC1D80 and LC1D95) in motor starter assemblies. It continuously monitors phase currents and disconnects the motor when an overload or phase imbalance is detected, helping prevent motor winding damage and lengthy system downtime.

This relay is suitable for larger three-phase motors and electrical loads requiring precise thermal protection with adjustable tripping settings.

🛠️ Key Features & Benefits

• Adjustable Current Range (63–80 A) — Fine-tune the overload protection to match the full-load current (FLC) of your motor for optimal safeguarding.

• Class 10A Trip Characteristic — Balanced trip response suited for motor applications, tolerating short start-up currents while tripping on sustained overloads.

• Three-Pole Protection — Monitors all three phases of the motor circuit to detect overload, phase loss, and unbalance.

• Phase Loss & Unbalance Detection — Enhances safety by sensing and responding to abnormal current conditions that could damage motors.

• Manual/Automatic Reset & Test Function — Test and reset options make maintenance and troubleshooting easier without removing power.

• Auxiliary Contacts (1 NO + 1 NC) — Provides signalling for fault indication and control panel integration.

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

• Compact Industrial Design — Easy installation beneath compatible contactors or on DIN rail/panel.

🧰 Why Use the LRD3363 Overload Relay?

Thermal overload relays like the LRD3363 are critical in industrial environments where motors face heavy use and variable loads. They act as an early-warning system, disconnecting the motor when overheating or overload conditions arise. This helps:

• Prevent motor damage caused by sustained overcurrent

• Reduce unplanned downtime and maintenance costs

• Improve safety across electrical installations

• Extend motor and control equipment life through precise protection

By integrating seamlessly with Schneider contactors and control panels, the LRD3363 enhances both performance and safety of medium-to-large motor control systems.

📌 Typical Applications

• Industrial motor starter assemblies

• Pumps, compressors & conveyors

• HVAC systems with large motors

• Material handling and production lines

• Commercial electrical panels requiring accurate overload protection