TELEMECANIQUE LT3 SM00M PTC Thermistor Protection Relay

Overview

TELEMECANIQUE LT3SM00M is a TeSys LT3 series PTC thermistor protection relay for motor winding temperature monitoring. TELEMECANIQUE LT3SM00M works with built-in PTC probes inside motor windings, detects overheating condition and triggers relay output for motor thermal protection. This TELEMECANIQUE LT3SM00M is widely stocked as spare thermal protection unit for motor control assemblies.

Features

TELEMECANIQUE LT3SM00M supports manual reset mode, equipped with front integrated test and reset button. It has power and fault LED indicators for local status check. It accepts series connected PTC thermistor probes, trips when probe resistance reaches 2700Ω to 3100Ω, and reset only after resistance drops below 1500Ω to 1650Ω. LT3SM00M is powered by dual voltage 115VAC or 230VAC 50/60Hz. It provides 1NO plus 1NC changeover contact for interlock and fault signal transmission to PLC or host control system. It also supports remote reset input terminal for external reset button connection. This unit adopts cage clamp terminal and standard DIN rail mounting. It complies with IEC 60034-11, UL and CSA standards. It is discontinued by manufacturer and still available as maintenance spare part. It is designed for 24/7 continuous operation on pump, fan, compressor and conveyor motor control panels.

Specifications

TELEMECANIQUE LT3SM00M Thermistor Protection Relay Brand: TELEMECANIQUE Schneider Electric Model: LT3SM00M Series: TeSys LT3 Type: PTC thermistor motor protection relay Power supply: 115 230 VAC, 50 60Hz Reset mode: manual reset, local button and remote reset input Contact configuration: 1NO + 1NC Contact rating: 5A at 250VAC Trip resistance range: 2700Ω ~ 3100Ω Reset resistance threshold: below 1500Ω ~ 1650Ω Indication: power LED, fault LED Test function: built-in test button Mounting: DIN rail TH35 Terminal: cage clamp terminal Protection class: IP20 Ambient temperature: -20℃ ~ +60℃ Status: discontinued legacy motor thermal spare

Principle

TELEMECANIQUE LT3SM00M monitors the resistance of PTC thermistor probes embedded in motor winding. This PTC Thermistor Protection Relay detects sharp resistance rise when winding temperature exceeds safe limit. The relay trips and locks the fault state, cutting motor control circuit and sending alarm signal. Manual reset is required after motor temperature cools down.

Applications

TELEMECANIQUE LT3SM00M is deployed in three-phase motor feeders, water treatment pumps, HVAC fans, compressors and injection molding machine drive systems. It provides direct winding overheat protection to supplement conventional overload relay. TELEMECANIQUE LT3SM00M is stocked as spare thermistor relay for TeSys motor control assemblies.