Manufacturing thermal protectors and switches since 2010.

HCET 3MP Series Thermal Protector Technical Principle

December 11, 2023

3MP series thermal protectors are widely used in 120V and 250V AC circuits in household motors (such as washing machines, dishwashers, dryers and vacuum cleaners, etc.) and industrial motors. The 3MP series thermal protectors have become a well-recognized product in the industry due to their wide application in household motors and industrial motors and their emphasis on installation flexibility and cost-effectiveness.


HCET 3MP Series Thermal Protector Technical Principle
Send your inquiry

3MP thermal protector is a thermal protector designed with S-shaped heating wire. This design makes it have higher current sensitivity and can respond to changes in current more accurately. In addition, 3MP uses alloy contacts, with one contact on a bimetallic strip and the other on the base plate. This design ensures the high life reliability and high stability of the thermal protector, allowing it to work stably for a long time.

3MP thermal protectors are also available in a variety of standard terminal configurations and carefully selected materials, making the product easy to operate and install. Custom terminal configurations are also available if required and can be easily connected to standard crimp terminals via connectorized wires. Such design features allow 3MP to have flexible installation methods and can adapt to different needs.

The 3MP series thermal protector uses a combination of bimetallic sheet and heating wire technology, which makes it have excellent thermal sensitivity and current sensitivity. When an overload condition occurs on the equipment, especially when the rotor is blocked, the 3MP thermal protector can respond quickly and achieve precise tripping time, thereby effectively protecting the equipment and circuit. This combined technology provides the 3MP thermal protector with excellent protection performance, ensuring that the equipment operates normally within a safe range.

The bimetal thermal protector achieves reliable protection through a simple and efficient working principle. It operates by monitoring the passing current and ambient temperature. When the current or temperature exceeds the preset value, 3MP will quickly cut off the circuit to provide disconnection protection. This is triggered by the disc reaching a set disconnection temperature. When the device cools to a safe temperature, the contacts automatically reset, returning the circuit to normal operation.

Therefore, 3MP series thermal protectors are widely used in 120V and 250V AC circuits in household motors (such as washing machines, dishwashers, dryers and vacuum cleaners, etc.) and industrial motors. 3MP has become one of the most recognized products in the industry for its reliability, performance and cost-effectiveness.

Small size and easy installation are one of the characteristics of 3MP series thermal protectors. It has a small size and is easy to install in various devices.

The 3MP series thermal protector also has power-off protection and time-delay protection functions. When the temperature or current exceeds the set value, the protector will quickly cut off the circuit and play the role of power-off protection. At the same time, the delay protection function can prevent sudden current surges in a short period of time.

In addition, the 3MP series also provides a variety of terminal installation methods, including co-directional and non-directional riveting and co-directional and non-directional inserting, etc., making it wider applicable and more flexible in installation.

The 3MP series thermal protector/thermostat has become one of the most recognized products in the industry due to its wide application in household motors and industrial motors, as well as its emphasis on installation flexibility and cost-effectiveness. It achieves higher current sensitivity, life reliability and installation flexibility through S-shaped heating wire design, alloy contacts and various terminal configurations, providing users with an excellent user experience.


Send your inquiry

Attachment: