Handcart Fixed Type Vacuum Circuit Breaker

Electric arc steel-making industries, etc. frequent operation required, as a control and protection equipment.

Description

The Handcart type indoor vacuum circuit breaker is suitable for 12kV. Apply to industrial and mining enterprises, substation and transmission and distribution systems for control and protection switching; particularly suitable for metallurgy. Electric arc steel-making industries, etc. frequent operation required, as a control and protection equipment.

The working principle of vacuum circuit breakers is different from other circuit breakers in that the extinguishing medium is different. There is no conductive medium in vacuum, which quickly extinguishes the arc. Therefore, the distance between the dynamic and static contacts of this circuit breaker is very small. This circuit breaker is generally used in auxiliary power configurations with relatively low voltage levels!

Structure and working principle of circuit breakers

There are many manufacturers and models of vacuum circuit breakers. According to usage conditions, it is divided into two types: indoor (ZNx - * *) and outdoor (ZWx - * *). It mainly consists of a frame part, an arc extinguishing chamber part (vacuum bubble), and an operating mechanism part.

The circuit breaker body is composed of a conductive circuit, an insulation system, seals, and a shell. The overall structure is a three-phase common box type. The conductive loop is formed by connecting the incoming and outgoing line conductive poles, the incoming and outgoing line insulation supports, conductive clips, and soft connections to the vacuum arc extinguishing chamber.

The mechanism is electric energy storage, electric opening and closing, and also has manual function. The entire structure is composed of closing springs, energy storage systems, overcurrent releases, opening and closing coils, manual opening and closing systems, auxiliary switches, energy storage indicators, and other components.

working principle

When a vacuum circuit breaker utilizes high fidelity air current to flow through zero, the plasma rapidly diffuses and extinguishes the arc, completing the purpose of cutting off the current.

Action principle

Energy storage process: When the energy storage motor 14 is connected to the power supply, the motor drives the eccentric wheel to rotate, and the roller 10 next to the eccentric wheel drives the crank arm 9 and connecting plate 7 to swing, pushing the energy storage pawl 6 to swing, causing the ratchet 11 to rotate. When the pin on the ratchet 11 is against the plate of the energy storage shaft sleeve 32, the two move together, causing the closing spring 21 hanging on the energy storage shaft sleeve 32 to elongate. The energy storage shaft sleeve 32 is fixed by a positioning pin 13 to maintain the energy storage state. At the same time, the crank arm on the energy storage shaft sleeve 32 pushes the travel switch 5 to cut off the power supply of the energy storage motor 14, and the energy storage pawl is lifted to reliably detach from the ratchet wheel.

Closing operation process: When the mechanism receives the closing signal (the switch is in the disconnected and stored energy state), the iron core of the closing electromagnet 15 is sucked downwards, and the positioning component 13 is pulled to rotate counterclockwise to release the energy storage maintenance. The closing spring 21 drives the energy storage shaft sleeve 32 to rotate counterclockwise, and its cam presses the transmission shaft sleeve 30 to drive the connecting plate 29 and rocker arm 27 to move, causing the rocker arm 27 to buckle onto the half shaft 25, causing the mechanism to be in a closed state. At this point, the interlocking device 28 locks the positioning component, preventing the positioning bull from rotating counterclockwise, achieving the purpose of mechanism linkage and ensuring that the mechanism cannot be closed in the closed position.

Opening operation process: After the circuit breaker is closed, the opening electromagnet receives a signal, the iron core pulls in, and the top rod in the opening release 19 moves upwards, causing the release shaft 16 to rotate, driving the top rod 18 to move upwards, pushing the bending plate 26 and driving the half shaft 25 to rotate counterclockwise.

Half axis 25 and rocker arm 27 are released, and under the action of the opening spring, the circuit breaker completes the opening operation

Environmental requirements

A.The altitude shall not exceed 1000m;

B. the environment temperature, maximum temperature + 40 ℃, the maximum temperature of 15 ℃ (only allow - 30 ℃ storage);

C. Environmental humidity: daily average relative humidity is 95%, and monthly average relative humidity is less than 90%, Daily average saturated vapor pressure acuities were 2.2 * 10 ^ 3 mpa

Daily average saturated vapor pressure acuities were 1.8 * 10 ^ 3 mpa

D. No fire, no dangerous dressing, no serious contamination, no chemical Fuji and no violent shaking.

If there are special conditions of use, please inform the manufacturer when ordering.

The operating mechanism adopts spring energy storage type, advanced and reasonable cushioning device, no rebound of opening, reducing impact and vibration of opening.

It is an indoor switchgear with three-phase AC 50Hz rated voltage of 12KV power system. It is used as protection and control unit for power equipment and industrial and mining enterprises. Applicable to places that require frequent operation at rated operating current, or multiple times to break short-circuit current.

The circuit breaker adopts an integrated design of the operating mechanism and the circuit breaker body, and can be used as a fixed installation unit, or can be equipped with a special propulsion mechanism to form a hand truck unit.

Features: small size, light weight, suitable for frequent operation

Main structure: vacuum interrupter, electromagnetic or spring operating mechanism, bracket and other components.

The main technical parameters:

NO	Item	Units	Technical parameters
1	Rated voltage	KV	12
2	Rated short-duration power frequency withstand voltage		42/48(Interphase, ground/fracture)
3	Rated lightning impulse withstand voltage		42/48(Interphase, ground/fracture)
4	Rated frequency	Hz	50
5	Rated current	A	630 1250	630 1250 1600 2000 2500 3150	630 1250 1600 2000 2500 3150
6	Rated short-circuit breaking current	KA	20/25	31.5	40
7	Rated short-time withstand voltage	KA	20/25	31.5	40
8	Rated short circuit duration	S	4
9	Rated peak withstand current	KA	50/63	80	100
10	Rated short circuit closing current	KA	50/63	80	100
11	Secondary circuit power frequency withstand voltage (1min)		2000
12	Rated single / back to back capacitor group breaking current	A	630/400(40kA:800/400)
13	Rated capacitor bank closing current		12.5 (frequency is not greater than)
14	Mechanical life	KA	20000
15	Rated current breaking times (electrical life)	KA	20000
16	Rated short circuit current breaking times	times	50(40KA≤30)
17	Dynamic and static contacts allow wear cumulative thickness	mm	3
18	Energy storage time	s	≤10
19	Contact opening distance	mm	11±1
20	Overtravel	mm	3.5±0.5
21	Contact closing bounce time	ms	≤2(40KA≤3)
22	Three-phase split/closed period	ms	≤2
23	Average opening speed (contacts are separated by -8mm)	m/s	1.2±0.2
24	Main conductive loop resistance	m/s	0.6±0.2
25	Main conductive loop resistance	μΩ	≤50(630A)≤45(1250A) ≤40 (1600,2000A)≤35 (2500A or more)
26	Rated operation sequence		0-0.3s-Co-180s-Co