Schneider Thermal Overload Relay LRD22

Schneider Electric LRD22 Thermal Overload Relay — Reliable Three-Phase Motor Protection

The Schneider Thermal Overload Relay LRD22 is a dependable protection component from Schneider Electric’s TeSys LRD family, engineered to safeguard medium-capacity three-phase motors against prolonged overcurrent, phase loss, and imbalance conditions. Designed for industrial and commercial electrical systems, this relay delivers robust thermal protection and forms a key part of motor starter assemblies when paired with compatible Schneider contactors like LC1D18 through LC1D32.

🔌 What Is the Schneider LRD22 Thermal Overload Relay?

The LRD22 is a three-pole thermal overload relay with an adjustable current protection range of 16 – 24 A, making it ideal for medium-load three-phase motor applications up to approximately 11 kW at 400 V AC. Its primary function is to detect sustained overcurrent, phase loss, or imbalance and disconnect the motor circuit before damage occurs — helping prevent overheating and costly failures.

With a Class 10A trip characteristic, the LRD22 balances tolerance for normal motor start-up inrush currents with reliable response to prolonged overloads, aligning with IEC motor protection standards.

🛠️ Key Features & Benefits

• Adjustable Current Range (16–24 A): Precisely set motor protection to match your full-load current requirements.

• Three-Pole Thermal Monitoring: Ensures balanced detection of overload, phase loss, and unbalanced currents across all phases.

• Class 10A Trip Characteristic: Offers dependable tripping under sustained overload while tolerating brief inrush currents.

• Phase Loss & Unbalance Protection: Enhances safety by disconnecting the motor when abnormal phase conditions are detected.

• Manual/Automatic Reset Options: Lets you choose between automatic recovery or manual reset after a trip event for flexibility.

• Auxiliary Contacts (1NO + 1NC): Provides fault signalling to control panels or automation systems.

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

• Compact Design for Easy Mounting: Fits directly under compatible contactors or on DIN rails/panels in control enclosures.

⚙️ Why Choose the LRD22 Overload Relay?

Thermal overload relays like the Schneider LRD22 are essential for motor control systems because they help:

• Prevent motor overheating and winding damage due to overcurrent conditions

• Reduce unscheduled downtime by responding early to faults

• Enhance system safety and reliability through balanced phase protection

• Lower maintenance needs and repair costs by preserving motor health

This makes the LRD22 especially suitable for control panels, starter assemblies, and protection circuits across manufacturing, processing, and commercial electrical installations.

📌 Typical Applications

• Motor starter panels with compatible Schneider Electric contactors

• Pumps, compressors, and fan motor circuits

• Conveyor and material handling systems

• HVAC motor protection and ventilation drives

• Automated production lines and machinery

• Industrial and commercial electrical panels requiring reliable overload protection

The LRD22’s adjustable range and sturdy design make it a versatile choice for three-phase motor protection in varied environments.