Vacuum-circuit :

General Description

ZN68-12 series of vacuum circuit breaker is three-phase A.C 50Hz indoor high-voltage distribution device with 12kV indoor high-voltage and below. This kind of circuit breaker is characterized by simple construction, strong switching capability, long life, complete operating functions and convenient maintenance. It is suitable to control and protect transmission plant and substation, especially used in the fields where it is frequently operated.
The operating mechanism of this series of circuit breaker is that of spring energy-stored type which can be operated by A.C or D.C, also by manual control

  • Applying Ambient Conditions
    The elevation should be no higher than 1000m.

  • Ambient Temperature
    The max. temperature should be +40
    The min. temperature should be -10

  • Relative Humidity
    The average humidity of a day should be no more than 95%
    The average humidity of a month should be no more than 90%

  • Saturated Vapor pressure
    The average saturated vapor pressure of a day should be no more than 2.2x10-3Mpa
    The average saturated vapor pressure of a month should be no more than 1.8x10-3Mpa

    It should be used in the places without fire, explosion, serious filth, chemical erosion and violent vibration.

Rated voltage Rated power frequ-
ency with-
stand voltage
Rated lighting impulse with-
stand voltage
Rated short circuit brea-
king current
Rated short circuit making current Rated dur-
short circuit
Rated switc-
hing opera-
anical Endur-
Rated current (A)
1000 1250 1600 2000 2500 3150 4000
kV kV kV kA kA s
12 42 75 20 50 4 30 10000
12 42 75 25 63 4 30 10000
12 42 75 31.5 80 4 30 10000
12 42 75 40 100 4 30 10000
12 42 75 50 125 4 30 10000
  : Products available   : Products to be developed

Korea market requires the products with korea characteristics. ZN28 type and Zn12 type vacuum circuit breaker with its respective outstanding advantages have been in favor with the mass of the customers. We herein recommend you the newly successfully developed ZN68-12 series of vacuum circuit breaker whose technical specifications and characteristics for the vacuum circuit breaker of new generation.
Theoretical calculation and comprehensive type test indicate that newly designed high switching capability, cut-off capability and high reliability which can make the circuit breaker reach higher technical specifications within smaller space compared with the vacuum interrupter with same diameter.
New construction and material of electrode for the vacuum interrupter with outstanding properties can ensure various technical and economical specifications advanced and reasonable, and satisfy the requirements for low cut-off and basically no string breakdown.

The circuit breaker not only has stable switching capability. but also string breakdown.

Air-insulated structure adopted in high pressure side can meet various requirements of national and ministry standards, including requirement of national and ministry standards, including requirement for creepage distance between air spacing and insulator surface. therefore, there is no need for a barricade in the middle of it.

Careful design for current path including static end bearer and moving end bearer can be to minimize the influence of electric force generated by short circuit current on the moving parts, which can make the circuit breaker stable. It can get the best result of dissipating heat at the same time when minimizing the loop resistance.

It can ensure the property and service life of the circuit breaker by adopting domestic spring operating mechanism which is specially used in the vacuum circuit breaker.

Its construction is clear and operating theory is familiar to people, which really realizes little maintenance, high reliability, beautiful appearance and durability. It can fix cabinet and can be assembled into small cart which is suitable to be used in many kinks of cubical switchboard.

The circuit breaker has a variety of specifications which satisfy many requirements.
1 Rated Short circuit breaking current kA 20  31.5  40
2 Rated Short circuit making current kA 50  80  100
3 Rated Short time withstand current kA 20  31.5  40
4 Rated withstand current (peak) kA 50  80  100
5 Rated Duration of short time s 4
6 Rated switching operations of short circuit  current 30
7 Mechanical endurance 10000
8 Closing time ms 75
9 Opening time ms 65
10 Switching current for single capacitor bank A 630
11 Switching current for back to back capacitor bank A 400
12 Rated voltage for energy-stored generator V DC220,110  AC220,110
13 Closing Voltage V DC220,110  AC220,110
14 opening Voltage V DC220,110  AC220,110
15 Power for Opening and closing coil w 275


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