| Brand | ROCKWILL |
| Model NO. | 36kV 72.5kV Dry Air Insulated Dead Tank Vacuum Circuit Breaker(VCB) |
| Rated voltage | 36kV |
| Rated normal current | 2000A |
| Rated frequency | 50/60Hz |
| Series | NVBOA |
Description
The Dry Air Insulated Dead Tank VCB was born of superb technology and abundant production experience of Meidensha Corporation.It is a circuit breaker employing vacuum interrupters and dry air for insulation. In order to use no SF6, which is global warming gas, there is no fear to decomposition of gas due to current interruption. It is therefore a highly reliable and high-performance circuit breaker.
Feature
Dead Tank Type VCB optimized for green procurement. It uses dry air for insulation in place of the SF6 which is specified as a greenhouse gas. Our basic design concept is to realize the environmental factors in design (The 3Rs (Reduce, Reuse, and Recycle) + LS (Longuse & Separable)) and life-cycle cost (LCC) reduction as basic concepts.
Contribution to global warming prevention
Dry air insulation are employed instead of SF6 gas insulation. GWP (Global Warning Potential) of SF6 is 23,900.
Excellent breaking performance
Since each current breaking section employs a vacuum interrupter, insulation recovery characteristics are excellent. It exhibits superb characteristics in cases of short-circuit interruption and short line fault interruption.
Sucient capability against multiple strokes and evolving faults
Since the vacuum interrupters used are of completely self-arc-diusion type, this circuit breaker is the only unit that is capable of disposing of multiple strokes and evolving fault currents.
Reduction of maintenance labor
Use of vacuum interrupters in the current breaking sections eliminates requirements of inspection for these sections. Therefore, man-hours can be saved for maintenance and inspection.
Type and Ratings
|
Rated voltage (kV) |
36 |
72.5 |
|
|
Withstand |
1 min power frequency (kV rms) |
70 |
140 |
|
1.2x50μs impulse (kV peak) |
200 |
350 |
|
|
Rated frequency (Hz) |
50/60 |
||
|
Rated normal current (A) |
2000 |
2000/3150 |
|
|
Rated short circuit breaker current (kA) |
31.5 |
40 |
|
|
Rated transient recovery voltage |
Rate of rise (kV/μs)) |
1.19 |
1.47 |
|
First pole to clear factor |
1.5 |
||
|
Rated short circuit making current (kA) |
82 |
104 |
|
|
Rated short time current (kA) |
31.5 (3s) |
40 (3s) |
|
|
Rated breaking time (cycle) |
3 |
||
|
Rated opening time (s) |
0.033 |
0.03 |
|
|
Make time with no load (s) |
0.05 |
0.10 |
|
|
Operating duty |
O-0.3s-CO-15s-CO |
||
|
Closing control voltage (Vdc) |
48, 100, 110, 125, 250 |
||
|
Rated tripping voltage (Vdc) |
48, 100, 110, 125, 250 |
||
|
Supply voltage for charging motor |
(Vdc) |
48, 100, 110, 125, 250 |
|
|
(Vac) |
60, 120, 240 |
||
|
Rated dry-air pressure |
0.5MPa-g (at 20℃ ) |
||
|
Closing operation system |
Spring |
||
|
Tripping control system |
Spring |
||
|
Applicable standard |
IEC 62271-100-2008, ANSI/IEEE C37.06-2009 |
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Construction
Overall construction
For each phase, a current breaking vacuum interrupter is accommodated in the grounded tank. The operation system is such that closing and tripping are effected by spring force.The operating mechanism and 3-phase interlinkage are assembled on a common base, which is installed on the frame legs.
Internal construction
The overall structure is composed mainly of grounded tank, vacuum interrupters (VI), insulating rods, bushings and main circuit terminals. Each grounded tank is filled with dry air maintained at a rated pressure of 0.5MPa-g (20℃).
Internal construction of vacuum circuit breaker
Dry air system
Outline drawing
Dimensions (72.5kV)
Dimensions (36kV)
Standard connection diagram
Performance
Performance of the circuit breaker has been designed in accordance with ANSI and IEC standard, and verified by type test. All products are shipped after confirmation of various performances by acceptance test based on these standards.
Withstand voltage characteristics ：Performance of withstand voltage is assured at the specified dry air pressure. Even though the dry air pressure has been lowered to the alarming level, the required insulation level can be assured.In addition, even though this pressure lowers to the atmosphericpressure, the circuit breaker withstands the rated voltage.
Current passing performance ：Since the main contacts are located under vacuum, their surfaces are never oxidized and current passing performance is therefore stabilized. In the closing mode of circuit breaker, a pressing force is exerted between main contacts by the effect of pressing spring and sufficient tolerance is assured against closing current and short-time current.
Mechanical life ：Due to adoption of simplified operating mechanism, switching characteristics are extremely stabilized. Frequent switching performance has also been verified through continuous mechanical switching test by repeating switching operations more than 10,000 times.
Electrical life ：Since current breaking is performed in the vacuum interrupter,arcing energy generated during current interruption is extremely low and contact erosion is minimal. This implies long contact life.Load current switching : 10,000 times
Rated breaking current switching : 20 times
Integral Tank Structure: The breaker's arc quenching chamber, insulating medium, and related components are sealed within a metal tank filled with an insulating gas (such as sulfur hexafluoride) or insulating oil. This forms a relatively independent and sealed space, effectively preventing external environmental factors from affecting the internal components. This design enhances the insulation performance and reliability of the equipment, making it suitable for various harsh outdoor environments.
Arc Quenching Chamber Layout: The arc quenching chamber is typically installed inside the tank. Its structure is designed to be compact, enabling efficient arc quenching within a limited space. Depending on different arc quenching principles and technologies, the specific construction of the arc quenching chamber may vary, but generally includes key components such as contacts, nozzles, and insulating materials. These components work together to ensure that the arc is quickly and effectively extinguished when the breaker interrupts the current.
Operating Mechanism: Common operating mechanisms include spring-operated mechanisms and hydraulic-operated mechanisms.
Spring-Operated Mechanism: This type of mechanism is simple in structure, highly reliable, and easy to maintain. It drives the opening and closing operations of the breaker through the energy storage and release of springs.
Hydraulic-Operated Mechanism: This mechanism offers advantages such as high output power and smooth operation, making it suitable for high-voltage and high-current class breakers.
