Schneider Electric - LT3SE00BD - TeSys LT3 PTC Probe Relay with Automatic Reset,

The Schneider Electric LT3SE00BD is a TeSys LT3 PTC (Positive Temperature Coefficient) probe relay designed to monitor and protect motors and equipment from overheating. It operates by interfacing with PTC thermistor probes embedded in motor windings or other machinery components. Upon detecting temperature anomalies, the relay initiates protective measures to prevent damage. This model features an automatic reset function and is compatible with a 24 V DC control circuit voltage. Equipped with a single normally closed (1 NC) contact, it ensures reliable interruption of control circuits during fault conditions. The LT3SE00BD is suitable for applications requiring continuous temperature monitoring and automatic recovery once normal conditions are restored. Please note that this product was discontinued on October 9, 2023. The recommended replacement is the RM35TM50MW motor voltage and temperature control relay.  

Technical Specifications:

• Control Circuit Voltage: 24 V DC

• Reset Function: Automatic

• Contact Configuration: 1 NC (Normally Closed)

• Conventional Free Air Thermal Current (Ith): 5 A for output control relay

• Rated Insulation Voltage (Ui): 500 V AC for output control relay

• Rated Operational Voltage (Ue): 250 V AC, 50/60 Hz for output control relay

• Resistance Thresholds:

• Reset: 1500…1650 Ω

• Tripping: 2700…3100 Ω

• Number of Probes Supported: Up to 6

• Short Circuit Detection Resistance: < 20 Ω

• Connections - Terminals: Cage type connectors supporting various cable sizes

• Tightening Torque: 0.8 N·m

• Dimensions (H x W x D): 100 mm x 22.5 mm x 100 mm

• Product Weight: 0.22 kg

• Standards Compliance: IEC 60034-11, VDE 0660

• Certifications: LROS (Lloyd’s Register of Shipping)

• IP Degree of Protection: IP20

• Operating Ambient Temperature Range: -25°C to +60°C

• Storage Temperature Range: -40°C to +85°C

• Operating Altitude: Up to 1500 m without derating; above 1500 m up to 3000 m with derating

• Vibration Resistance: 1 gn (25…150 Hz) and 2.5 gn (2…25 Hz)

• Shock Resistance: 5 gn for 11 ms

• Electromagnetic Compatibility:

• Immunity to microbreaks and voltage drops

• Resistance to electrostatic discharge (Level 3)

• Resistance to fast transients (Level 3)

• Surge resistance (Level 4)

• Susceptibility to electromagnetic fields (Level 3)