This is an electric motor thermal switch with dual protection against overload and overheating. It adopts bimetal and PTC temperature sensing structure motor temperature switch and thermostat.
Structure of electric motor thermal switch
Multifunctional motor thermal switch housing includes
1. Fixed seat
2. PTC heating element
3. Moving contacts
4. Static contact
5. Bimetallic components
6. Static contact piece
7. Conductive sheet
8. Overload heating device
9. Adjusting board
10. Right terminal
11. Left terminal
12. Welding boss of left terminal heating device
13. Welding boss of static contact piece heating device
14. Elastic conductive card with static contact piece in contact with PTC heating element
15. The elastic conductive card with the right terminal in contact with the PTC heating element
16. The welding point of the bimetal element of the right terminal
17. Shell fixing grooves on both sides of the outer edge of the fixing seat

18、19、Welding boss of adjusting plate
20. The static contact socket in the fixed seat
21. PTC heating element socket in the fixed seat
22. Overload heating device socket in the fixed seat
23. Placement slot for bimetal components and adjusting plate
24, heat flow channel
25. The movable contact 4 is connected with one end of the bimetal element 6 to form a bimetal element assembly; The static contact piece 7, the conductive piece 8, the right terminal 11, and the left terminal 12 are preset in the fixing base 2 to form a fixing base assembly; The fixed seat assembly is provided with a stationary contact socket 21, a PTC heating element socket 22, an overload heating device socket 23, a bimetal element, and a positioning groove 24 for the adjustment plate; After placing the static contact 5 in the static contact socket 21 provided in the fixing seat and connecting with the static contact sheet 7, the bimetal component assembly is placed in the positioning groove 24 of the bimetal element and the adjusting plate in the fixing seat 2. Connect with the welding point 17 of the bimetal element of the right terminal; Finally, the adjusting plate 10 is placed in the bimetal element in the fixing base 2 and the positioning groove 24 of the adjusting plate; The welding boss 20 provided at one end of the adjusting plate 10 is again connected to the middle position of the bimetal element welding point 17 of the right terminal, forming a component of the thermal protection switch; Place the PTC heating element 3 in the holder 2 PTC heating element socket 22, thus forming a multifunctional motor protection switch assembly; After the multifunctional motor protector assembly is put on the shell 1, the parts of the shell are simultaneously fixed in the shell fixing grooves 18, 19 on both sides of the outer edge of the fixing base with fixing clamps.


The conductive sheet can be cut off according to the needs of the motor protector to bridge the overload heating device with corresponding technical parameters. When the motor generates abnormal current and needs to be protected, the conductive sheet 8 should be cut off, The overload heating device 9 corresponding to the technical parameters is respectively bridged with the welding boss 13 of the heating device of the left terminal and the welding boss 14 of the heating device of the static contact piece. The overload heating device 9 is placed directly under the bimetallic element, which can protect the abnormal current of the motor and at the same time enable the bimetallic element to be sensitive to temperature for overheating protection. In addition to the above-mentioned PTC heating element connected in parallel with the bimetal element, a multifunctional motor protector assembly with overload protection, overheat protection, and self-locking protection is formed. Considering the convenient installation and sealing requirements of the multifunctional motor protector, the left terminal 11 and the right terminal 12 can be connected with leads, the shell can be metal or non-metal, and the package can be riveted or epoxy potted.

Overload heating device 9: It is an electric heating wire, an electric heating plate or other heating elements or materials.

PTC heating element 3: use ceramic PTC heating element or other heating elements or materials.

2. Feature 1: The conductive sheet can be cut off according to the needs of the motor protector to bridge the overload heating device with corresponding technical parameters.

3. Feature 2 lies in: The overload heating device is respectively bridged with the welding boss of the left terminal heating device and the welding boss of the static contact piece heating device, and the overload heating device is placed directly under the bimetal element.

4. Feature 3 is: The overload heating device is an electric heating wire or an electric heating plate or other heating elements or materials.