- Brand: Sprecher + Schuh
- Model: RT 3-M
- Type: Thermistor Protection Relay
- Part Number: 11292
- Technical Specs:
- Core Application: Thermal protection of electric motors, transformers, and machinery equipped with PTC thermistors against overload, blocked rotor conditions, phase failure, and insufficient cooling
- Operating Control Voltage: 220 V - 240 V AC
- Supply Network Frequency: 50 / 60 Hz
- Power Consumption: Approx. 3 VA
- Evaluation Circuit Layout: Designed to monitor a series string of Positive Temperature Coefficient (PTC) thermistor sensors embedded in the motor windings
- Number of Sensor Loops: 1 circuit loop tracking up to 6 PTC sensors in series conforming to DIN 44081 / DIN 44082 standards
- Cold Resistance Threshold: < 1.5 kΩ
- Triggering/Trip Threshold: 3.2 kΩ to 3.8 kΩ (Activates fault response upon winding overheating)
- Reset/Release Threshold: 1.5 kΩ to 1.8 kΩ (Allows resetting once the motor cools down)
- Reset Operation Modes: Manual reset
- Output Contact Configuration: 1 NO + 1 NC
- Maximum Contact Rating: 250 V AC, max. 5 A resistive / 2 A inductive load
- Status Indicators: Front-facing LED diagnostics; Red LED (Tripped/Overtemperature fault condition)
- Electrical Connection Type: Box lug screw clamp terminals
- Housing Construction Material: High-impact, flame-retardant polyamide/polycarbonate blend casing
- Structural Mounting Format: Standard 35mm DIN-rail mount (EN 50022 tracking) or surface screw panel installation
- Enclosure Protection Class: IP20
Weight: 275 g
Dimensions: 100 x 70 x 45 mm
Country of Origin: Switzerland
HS Code: 8536.49.00