STM6, STM6LY, STM6RT, STM6E and STM6EL series of circuit breakers are new upgraded circuit breakers researched and developed by the company combined with the advantages of similar international products and demand of domestic and international markets.
With insulation voltage up to 1000V, the circuit breaker is applicable for distribution systems of AC50Hz, rated working voltage 690V and rated working current from 10A to 800A, used to distribute electric power energy, protect circuits and power equipment against overload, short circuit, undervoltage and so on, also can be used for infrequent startup of motor and protect it from overload, short circuit or undervoltage.
It is featured with small size, high breaking, short flashover, etc., is the ideal product for users. It can be vertically installed or horizontally installed.
STM6DC series DC moulded-case circuit breaker (hereinafter referred to as circuit breaker) is suitable for DC systems of rated voltage up to and including DC 1000V and rated current 10~800A, used to distribute electric power energy, protect circuits and power equipment against overload, short circuit and so on.
The products can be fed with wires from top and bottom, and it is polarity-free.
It complies with the standards IEC60947-2, GB14048.2, etc.
 
Feature 1: current limiting capacity
Current-limiting refers to limit of the increase of short-circuit current in the loop, and in the loop protected by STM6, peak value of the short-circuit current and the I2t energy in the circuit will be much smaller than the prospective value.

U-shaped static contact
Unique U-shaped static contact can achieve pre-breaking technology:
The so-called pre-breaking technology refers to when short-circuit current flows through the contact system, electric power generated by U-shaped static contact and moving contact is mutual exclusive. The greater the short-circuit current is, the greater the repulsion of the electromotive force, and it is generated together with the short-circuit current at the same time. Before the trip action occurs, the electrodynamic repulsion force can make the static and moving contact separation, by increasing the arc to increase the equivalent resistance between them to achieve the purpose of suppressing increase of short-circuit current.

Feature 2: modularized accessories
Accessory: For the circuit breakers of the same frame, they has uniform sizes regardless of the breaking capacity and rated current;Accessory: Users can freely 
 choose and expand functions of circuit breakers according to their needs
Modularized accessories have insulation function, which is easy for hot-line operation and installation.

Feature 3: miniaturized frame, compact design
5 frame sizes: 125 type, 160 type, 250 type, 630 type, 800 type
Rated current of STM6 series 10A~800A 


Feature 4: contact repulsion device (patented technology)

The technical scheme adopted by the invention is:
As shown in Figure 1, the new contact device is mainly consisted of static contact, moving contact, shaft 1, shaft 2, shaft 3 and springs;
When the circuit breaker is in the closed state, shaft 2 acts on the right side of the spring angle; When the circuit breaker has a large fault current, the moving contact will be subjected to the electric repulsion generated by the current itself, and rotate with the center of shaft 1, when shaft 2 rotates to the top of the spring angle with the moving contact, it makes moving contact to rapidly rotate upwards and quickly break the circuit upon the reaction of spring, it has enhanced the breaking capacity of the product through optimization of the contact structure.

Feature 5: intelligent
Network communication is more convenient. It accesses to Modbus communication system through dedicated connection. STM6E / STM6EL with communication function can select monitoring accessories to realize door display, read, set and control.


Feature 6: modularized arc extinguishing system 


Feature 7: unification

The six series of STM6, STM6LY, STM6DC, STM6RT, STM6E, and STM6EL under the same frame size have the same dimensions, installation dimensions and appearance style, which is completely unified design.

Components of circuit breaker