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Temperature sensor and thermal protector for electric motors

Probes for electric motors

13 products

GUILCOR has been the French leader for more than 30 years in thermal probes and protectors for measuring the temperature of windings, bearings and the transmission of electric motors.

Whether for a three-phase, single-phase, synchronous or asynchronous motor, our resistance temperature sensors encapsulated in a metal tube or in a heat-shrinkable tube adapt to different types of motor. 
These measurement probes operate in various temperature ranges from -50°C to +260°C. 

The most common measuring elements are Pt 100, Pt 1000, Ni 1000, KTY, NTC, PTC etc... 

Our sensors are most often used to measure the temperature of windings, bearings, engine oil, and transmission. 
Other applications may include temperature measurements in laboratories and/or on test benches. 
Depending on the type of sensor, the electrical resistance of our measuring instruments varies.

Temperature probes for electric motor windings

To read the temperature in the electric motor windings, you will need a wired temperature sensor protected by heat shrink tubing. These measuring devices are distinguished by their high electrical resistance. 

Here are the characteristics of this type of probe for electric motor:

  • Measuring element: Pt 100, Pt 1000, Ni 1000, NTC, PTC, KTY, or other on request
  • Operating temperature range: temperature class -20°C to 180°C
  • Connection wires: Teflon FEP or PFA 0,22 mm or on request
  • Electrical resistance: 2.5 kV or higher on request
  • Ingress protection: IP 20
  • Connection: 2 wire, 3 wire or 4 wire

The parameters and design of the sensor can be adjusted as required.

Temperature probes for stator notch of electric motor

These measurement probes are distinguished by their high electrical resistance and are most often used to take the temperature in the stator slot of an electric motor.

Here are the specifications of this type of sensor: 

  • Detection element: Pt 100, Pt 1000, Ni 1000, NTC, PTC, KTY, other as requested
  • Measurement range: from -20°C to 180°C
  • Connecting wires: Teflon APFA
  • Electrical resistance: 12 kV
  • Protection class: IP 65
  • Connection: 2 wire, 3 wire or 4 wire

Parameters and design of the sensor for electric motor can be adjusted on request.

Temperature sensors for temperature measurement of bearings, oil and motor transmission

These are resistance temperature sensors encapsulated in a stainless steel tube. They stand out for their thermal resistance, which can go up to 400°C, depending on the type of cable selected. 
The protection index of these measurement probes can go up to IP 68. 
The design of the sensors depends on the application. You will then find probes for electric motors with: 

  • Smooth metal tube,
  • Thread, 
  • Contact temperature sensors, 
  • Temperature sensors with bayonet lock, 
  • Temperature sensors with connector, 
  • At right angles, etc. 

Whichever model you choose, our temperature sensors are highly resistant to shocks and vibrations.

Be aware, however, that measuring devices with bayonet locking ensure that the sensor is permanently pushed against the measured spot, thus protecting it against mechanical damage if the object to be measured vibrates. In addition, it ensures a better temperature reading.

Bimetal thermal protector for electric motor windings

Some bimetallic strips have an uninsulated metal casing and are energized.
ST01U1 type bimetallic strips are insulated by assembling a Kynar, Mylar (≤ 130°C) or Nomex (≥ 135°C) heat-shrink sheath. 
The switches have high voltage resistance up to 2 kV at 50Hz AC as well as class I VDE protection. They are particularly suitable for installation in motor windings.

PTC thermal protector for electric motor windings

The relationship between resistance and temperature is non-linear, it varies strongly with small temperature changes around the set point. 

The PTC thermistor probe is a small non-linear resistance sensor, which can be integrated into the winding of electric motors. It is made from a metal oxide or semiconductor material.

For correct positioning, the thermistors must be located near the thermally critical areas, or hot spots of the winding. This allows the temperature of the copper wires to be closely monitored. However, an offset will remain depending on the size of the probe and their installation in the winding.

Thermistors are for insertion into non-rotating parts of the actuator, such as the stator winding in an AC motor or the field windings in a DC motor.

Anti-condensation heating cables for electric motor windings

The shutdown heaters offered are intended for use in electrical machines. They are available in a wide variety of capacities, heating cable lengths or supply voltages.