What is a moulded case circuit breaker? It is a type of circuit breaker with a plastic case as protection, referred to as a plastic case circuit breaker, also known as an air switch.

It is suitable for.

1. 2000m above sea level and below.

2. ambient medium temperature not higher than +40°C (+45°C for marine use) and not lower than -5°C .

3 . Capable of withstanding the effects of humid air.

4. able to withstand the effects of salt and oil mist.

5. a maximum inclination of ±25.5°.

6. reliable operation under normal ship vibrations.

7. work reliably under earthquakes (4g)

8. in non-explosive media, where there are no insulating gases and conductive dusts sufficient to corrode the metal

9. in places where there is no rain or snow.

Moulded case circuit breakers are a new product derived from replacing fuses and knife switches. Regardless of how the products have been improved or changed, they generally have a six-link operating mechanism and no flying arc, which is a necessary feature of the most mainstream air switch circuit breakers on the market. As knife switches have no protection function, circuit breakers become the preferred choice.

Tessi Electric moulded case circuit breakers are divided into single pole (below 63A), three pole and four pole products according to the number of poles. The neutral pole (N-pole) types in four-pole products can be divided into the following four types.

Type A: N-pole without overcurrent decoupler, N-pole always connected, not combined with other three poles.

Type B: N-pole without overcurrent decoupler, N-pole combined with other three levels.

(Type C: N-pole with overcurrent decoupler, N-pole combined with other three poles; N-pole first closed then broken).

Type D: overcurrent decoupler mounted on N pole, N pole always connected, not combined with other three poles.

Taisi electrical circuit breakers can be divided according to rated current A (class).

-63 for 6, 10, 16, 20, 25, 32, 40, 50, 63A 9 levels (6A specifications without overload protection).

-100 for 10, 16, 20, 25, 32, 40, 50, 63, 80, 100A Class 10; S-3VI3-160 for 100, 125, 140, 160A Class 4.

-250 is eight grades of 100, 125, 140, 160, 180, 200, 225, 250A.

-400 is 5 grades of 225, 250, 315, 350, 400A.

-630 is grades 400, 500, 630A.

-800 is a 630, 700, 800A grade.

-1250 is 1000, 1250A secondary.

According to the wiring method can be divided into three kinds of front wiring, back wiring and plug-in.

According to the type of overcurrent decoupler, it can be divided into hot electromagnetic (duplex) type and electromagnetic (instantaneous) type.

The structure of the moulded case circuit breaker consists of operating mechanism, contacts, protection devices (various types of decouplers), arc extinguishing system, etc. The main contact closure of the moulded case circuit breaker is manual or electric. After the main contact is closed, the free release mechanism locks the main contact in the closed position. The coil of the overcurrent release and the thermal element of the thermal release are connected in series with the main circuit, and the coil of the undervoltage release is connected in parallel with the power supply.

When the circuit is short-circuited or severely overloaded, the armature of the overcurrent derailleur attracts, making the free derailleur mechanism act, and the main contact breaks the main circuit. When the circuit is overloaded, the thermal element of the thermal decoupler will heat up and bend the bimetal, pushing the free decoupling mechanism into action. When the circuit is under-voltage, the armature of the under-voltage derailleur is released and the moulded case circuit breaker simultaneously activates the free derailleur mechanism. The shunt release is used for remote control. During normal operation, its coil is de-energised. When distance control is required, pressing the start button energises the coil and the armature drives the free release mechanism into action, causing the main contacts to click open.