Schneider Electric LRD TeSys D Thermal Overload Relay

The Schneider Electric LRD thermal overload relay is the dedicated overload protection device for the TeSys D contactor family, covering 0.1 A to 150 A in a series of twelve overlapping current ranges that plug directly onto the TeSys D contactor body without interposing wiring — a design that reduces panel assembly time, minimises connection resistance, and ensures mechanical rigidity of the motor starter assembly. The LRD uses a bimetallic thermal sensing element that models motor heat accumulation across start, run, and overload phases, providing motor thermal protection that accounts for prior thermal history rather than just instantaneous current, which prevents nuisance tripping during hot motor restarts common in Saudi Arabia's high-ambient environments.

The LRD includes a test and reset button on the front face for manual trip simulation and reset after overload, a trip indicator flag visible without opening the panel, and a stop auxiliary contact output that opens the motor starter control circuit when the relay trips — providing automatic motor stopping without PLC intervention. Optional add-on auxiliary contact blocks provide an alarm (NO) contact output that can signal an imminent overload condition before the relay trips, enabling predictive warnings to the building management or SCADA system. The LRD's ambient temperature compensation mechanism adjusts the trip threshold by approximately 0.6% per degree Celsius, preventing over-protection in cold conditions and under-protection in the 50°C+ ambient temperatures common in Saudi summer plant rooms.

The TeSys LRD relay is the most widely used motor overload relay in Saudi Arabia, present in the enormous installed base of TeSys D starter assemblies across the Kingdom's industrial, commercial, and infrastructure sectors. Every DOL motor starter built to the standard Schneider Electric TeSys D assembly uses an LRD relay, giving it a directly proportional market presence to the TeSys D contactor. Emergency replacement supply is a critical service requirement, as a failed LRD overload relay is a common cause of motor starter downtime in Saudi industrial plants.

Razz Middle East stocks LRD overload relays in all twelve standard current ranges from 0.1 A to 150 A for same-day supply, with phase failure sensitivity selection and manual/auto reset options across all ratings.