Maestro Thermal switches

Bimetal thermal switches are electromechanical safety devices that interrupt the flow of current when the temperature exceeds a safety threshold, preventing overheating and burning of motors, transformers, and appliances. They use a strip composed of two different metals which, when heated, bend to open the circuit.

Operating principle

It relies on differential thermal expansion. Two different metals bonded together expand at different rates, causing bending as temperature changes.

Action: when the set temperature is reached, the bimetal strip bends rapidly (“snap action”) and opens the electrical contact.

Reset: once cooled, the bimetal returns to its original shape and closes the contact again (automatic reset), or requires manual reset in some models.

Unlike sensors that only carry signal currents, our bimetal switches are active components of the electrical circuit, connected in series with the protected appliances. They are also designed to interrupt and restore the electrical load for the minimum number of cycles required by the specific application.

The Maestro offering is structured into three main product families, designed to meet different application needs:

X3

Compact and versatile

The most compact bimetal thermal switch in the lineup, ideal for low- and medium-current applications.

  • up to 3 A for 10,000 cycles
  • up to 6 A for 6,000 cycles
  • Maximum current: 9 A

Also suitable for applications controlled by relays or electronic systems.

Request technical data sheet

X6

High performance

The protector is designed for applications with higher currents.

  • Up to 10 A for 10,000 cycles
  • Maximum current: 25 A
Request technical data sheet

X7

Maximum power

The solution for high-power applications and harsh conditions.

  • Up to 13 A for 10,000 cycles
  • Maximum current: 35 A
Request technical data sheet

If you have any questions or would like more information, please fill out the form: we’d be happy to get to know you and work with you to identify the best applications for your products.

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    Our strengths

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    Made in Italy

    100% European components

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    These elements guarantee consistent quality, long-term reliability, and full compliance with European regulations.

    FAQ

    Its operation is based on the mechanical deformation of a strip composed of two metals with different coefficients of thermal expansion. When the calibration temperature is reached, the strip bends instantly, snapping and opening the electrical contacts to interrupt the circuit.

    The tripping times depend on the thermal curve of the application and the type of thermal insulation of the device. Maestro protectors are designed to ensure rapid tripping, especially in critical conditions such as progressive overload or a locked rotor in an electric motor.

    Yes. As direct manufacturers, we develop thermal protectors with tripping thresholds calibrated to the customer’s specific needs, covering standard and special temperature ranges for industrial OEM applications.

    The PTC thermistor is a semiconductor sensor that changes its electrical resistance but requires an external electronic circuit to interrupt the current. The Maestro bimetallic protector, on the other hand, is a self-contained electromechanical switch that physically and directly interrupts the flow of current, offering superior intrinsic safety without the need for additional control boards.