Protect your motors and generators from overheating

Stator slot RTD sensor

Stator slot RTDs are embedded directly within stator windings to provide accurate, localized temperature monitoring and help prevent insulation failure and costly downtime.

Designed for industrial environments, these sensors are installed in the stator slots in direct contact with the windings and insulation. This placement ensures precise hotspot detection, improving equipment reliability, performance and operational safety. Also known as winding temperature detectors (WTDs), these resistance temperature detectors (RTDs) play a critical role in protecting high-value electrical machines from overheating that can lead to insulation damage, system failure and unplanned outages.

Product summary

  • Accurate temperature monitoring
  • Enhances motor longevity
  • Improves efficiency
  • Early failure detection
  • Ensures safety and cost savings

Understanding the function of stator slots

Electric AC motors and generators consist of two key components: a stationary stator and a rotating rotor. To ensure these vital parts operate safely and efficiently, effective thermal protection is essential, because most motor failures start with overheating of the stator windings.

Stator slots play an important role in this: they are long, narrow grooves in the stator core that hold and secure the copper windings. When AC current flows through these windings, a magnetic field is formed inside the slots and drives the motor. The slot design ensures the windings stay in place, are electrically insulated, and can be effectively cooled, which is crucial for safe and efficient operation.

Preventing motor failure with RTD sensors

Stator slot resistance temperature detectors (RTDs) provide highly accurate temperature monitoring inside the motor’s stator slots, protecting your equipment from overheating, insulation degradation, and costly unplanned downtime.

Overheating is the main enemy of motor insulation. For every 10°C increase in temperature, the insulation lifetime is cut in half. Electrical problems account for 47% of all motor failures, and winding failures alone make up 37%, showing how critical proper temperature monitoring is for protecting motor insulation.

This stator slot RTD sensor plays a major role in preventing extremely expensive motor damage. Large motors typically use six or more stator slot RTD sensors to ensure reliable, safe operation
under all load conditions.

Stator slot applications across industries

Stator slot RTDs or winding temperature detector (WTD) are used across many sectors where reliable electric motors and generators are critical, including:

  • Hydroelectric power stations
  • Wind turbines
  • Industrial manufacturing environments
  • Heavy-duty electric machinery and generator systems

In all these applications, precise temperature monitoring leads to:

  • Increased motor longevity
  • Improved operational efficiency
  • Early detection of faults or abnormal voltage conditions
  • Enhanced safety during high-demand operations
  • Reduced maintenance costs due to fewer insulation failures or mechanical breakdowns
Stator slot temperature RTD sensor from SMG

Advanced design for industrial demands

Stator slot RTDs feature sensing elements along most of their length, allowing for continuous average temperature readings across a broad area. This design ensureslocalized hot spots are detected, providing a complete and responsive view of the thermal profile within the stator slot.

Our SMG stator slot RTDs are engineered to meet the demands of high-performance industrial environments. Key characteristics include:

  • Flexible, non-inducible materials for optimal fit and performance
  • Flat and thin design for seamless embedding between windings
  • Bifilar construction to avoid induction-related errors
  • Durability under shock, vibration, and pressure
  • High accuracy, repeatability, and long-term stability
SMG Winding Temperature Detector

Download the stator slot RTD sensor leaflet

Download the stator slot RTD sensor leaflet for a quick overview of its added value, technical specifications, and typical applications.

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Custom solutions and precision with SMG

Our stator slot RTDs are manufactured by SMG in South-Korea. Trusted globally, SMG delivers high-performance thermal protection backed by proven Korean engineering. Most of their stator slot RTDs are delivered as custom-built solutions, tailored to the customer’s exact application and performance requirements.

Each sensor is calibrated and built to match your system requirements. Our engineers are happy to assist in selecting the best design for your application.

As an official distributor, Kamet is ready to support you in selecting the right stator slot configuration for your application.

Available specifications:

Let us help you find the best product

When doing business with Kamet, you can rely on fast and responsive customer service and consistent quality.

  • Response time: within 24 hours on working days
  • Delivery time: 3–4 weeks depending on design and configuration

Our team is ready to help you with technical advice, customization options, or quotations.

What do our customers say about us?

Kamet has been our reliable partner for more than two decades, consistently providing custom solutions that perfectly fit our requirements. Their commitment to understanding our needs and delivering results has been invaluable to our business. One example is that they have come up with an easy-to-apply improvement for one type of our high-temperature thermocouple designs. This enhancement significantly increased the working lifetime by several months, achieved by looking more in-depth at our application.

Highly recommended!
Marius Popovici Societatea Nationala Nuclearectrica S.A.
Correge company has been working with Kamet for more than 10 years now; we essentially bought MI thermocouple cables from class 1 to special limits to manufacture custom-made temperature sensors.

Kamet is well aware of its customers’ needs and has accompanied us through numerous projects. I enjoy working with them because they are responsive, everything is well organized, and they are all efficient and ready to help us.

They have developed their online portal, and I now have access to accurate information such as our prices, their stock and future deliveries, and values from certificates of calibration.

I highly recommend working with them.
Elodie Oudache Correge
Kamet has been a business partner of ours for many years. Among other things also for very important components of our products. The cooperation and partnership have developed very positively for both sides over the years.

Our wishes and suggestions are taken into account and if problems arise, we work together to find and implement a solution.

We look forward to many more years with Kamet as a business partner.
Renowned German-based sensor manufacturer
We have partnered with Kamet Trading as our preferred supplier for our heating wire/ cable requirements for a number of years, and their products have consistently exceeded our expectations.

We specialize in vacuum brazing of heating cables to stainless steel, copper and other alloys for components which on occasions are not serviceable items and hence the quality of the cables from a brazing perspective, workability, and performance with a long life expectancy of 7 to 10 years are critical. The quality of their heating cables is unparalleled, ensuring reliable performance and longevity even under the most demanding conditions especially in high vacuum and extreme temperature environments. The commitment to excellence throughout the supply chain which Kamet have established is evident in their premium products tailored to specific requirements of our most stringent quality control requirements.

Over the years Kamet have become a strategic supplying partner for us and we highly recommend them.
Arthur Miles Mat-Tech BV
Heaters supplied by Kamet are widely used in our UHV manipulators and reaction cells for controlled sample heating. Their compact diameter, flexibility, and high-temperature capability make them well suited for integration into confined geometries typical of ultra-high vacuum systems. In UHV manipulators, these heaters enable precise control of sample temperature during surface preparation, annealing, thin-film growth, and catalytic studies. The manipulators often provide multi-axis motion (XYZ translation and rotation) while maintaining pressures in the 10⁻⁹–10⁻¹⁰ mbar range. Low outgassing and vacuum compatibility are therefore critical. The hermetically sealed, magnesium-oxide insulated construction ensures minimal contamination and stable operation during bake-out procedures. In reaction cells attached to UHV systems, heaters from Kamet allow localized heating under controlled gas atmospheres, enabling in-situ studies of surface reactions, oxidation, reduction, or catalytic processes. Their robustness and uniform heat distribution support reproducible thermal conditions while preserving vacuum integrity in adjacent chambers.
Polish-based Precision & Vacuum Technology company
Working with Kamet was an excellent experience. As a first-time partner, we were impressed by their technical expertise and guidance in choosing an appropriate solution for our high-temperature cabling needs. Throughout the process, the team was incredibly cooperative and responsive, ensuring our stringent requirements were satisfied. Their commitment to quality and seamless communication streamlined the procurement process. Additionally, their post-sales support has been nothing short of perfect. We highly recommend Kamet.
Scuola Superiore Sant'Anna in Pisa

More about the usage of RTD Stator Slot sensors