Stator Winding RTD & Bearing Temperature Sensor (Motor Protection)
Electric motors and generators are the heart of industry, and overheating is their worst enemy. Hongtai Motor Protection Sensors are engineered to be embedded directly into the critical areas of rotating machinery. Whether you need a Stator winding RTD to monitor coil temperature or a robust Bearing temperature sensor to detect friction heat, our sensors provide the millisecond-response data needed to prevent catastrophic failures.
Unlike standard probes, our Embedded temperature probe series utilizes ultra-thin Chip RTD (Thin Film) elements. These compact, flat sensors can be inserted safely into the narrow slots between stator windings without damaging the insulation varnish, ensuring real-time thermal monitoring for Class F and Class H motors.
Key Technical Features & Benefits
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Ultra-Compact Chip Design: The flat, rectangular shape of the Chip RTD allows it to fit into stator slots as narrow as 2mm.
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High Dielectric Strength: Insulation is critical inside a motor. Our sensors are encapsulated in high-temperature epoxy or silicone glass plates, tested to withstand 2.5kV to 5kV to prevent short circuits.
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Shock & Vibration Resistant: Designed for the high-G environment of wind turbines and heavy pumps. The internal connection uses a specialized strain-relief structure.
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Fast Response: By placing the sensor directly against the copper winding or bearing race, thermal lag is virtually eliminated (T0.5 < 2s).
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Standard Compliance: Meets IEC 60034 standards for rotating electrical machines.
Technical Specifications (WZP-Motor Series)
| Parameter | Specification | Notes |
| Product Type | Stator winding RTD / Bearing temperature sensor | Embedded / End-face Type |
| Element | Pt100, Pt1000, Cu50 | Thin Film (Chip) |
| Accuracy | Class A (±0.15°C), Class B | Class B is standard for motors |
| Temp Range | -50°C to +200°C | Matches Class H Insulation |
| Probe Dimensions | Chip: 2x10x60mm (Customizable) | Probe: Ø3mm, Ø4mm, Ø6mm |
| Insulation Material | Epoxy Glass / Silicone / Shrink Tube | High Voltage Resistant |
| Lead Wire | Teflon (PTFE) / Silicone | Oil & Heat Resistant |
| Dielectric Strength | > 2000V AC / 1 min | Essential for HV Motors |
| Wire Configuration | 2-Wire, 3-Wire, 4-Wire | 3-Wire most common |
Application Scenarios
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Electric Motors: Embedding between phase windings to monitor core temperature.
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Wind Turbines: Monitoring the main shaft bearing and generator coils in nacelles.
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Industrial Pumps: End-face RTD probes installed in the pump housing to detect dry-running or bearing seizure.
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Generators: High-voltage stator monitoring in power plants.
Installation: Embedded vs. Bearing
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Stator Installation: The flat “Chip” sensor is sandwiched between the stator laminations and the copper winding during the vacuum impregnation process (VPI).
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Bearing Installation: A spring-loaded cylindrical probe is inserted into a drilled hole in the bearing housing, ensuring the tip presses firmly against the outer race of the bearing.
FAQ
Q: Do I need Pt100 or Pt1000?
A: Most industrial motor protection relays (like Siemens/ABB) use Pt100. However, for long cable runs or HVAC-related motors, Pt1000 is sometimes used to reduce line resistance error. Check your relay manual.
Q: Is the cable oil resistant?
A: Yes. Since these sensors often sit inside oil-filled gearboxes or near lubricated bearings, we use shielded Teflon (FEP/PTFE) cables that resist hot oil and aggressive chemicals.
Industrial Pt100 Sensors for external motor housing monitoring.
