High Voltage Circuit Breaker for 12kv Outdoor vacuum Circuit Breaker Protection Device

• Customization: Available
• Breaking Capacity: High Voltage Circuit Breakers
• Operation: Manual Type
• Model NO.: ZW20A-12F
• Speed: High-Speed Circuit Breaker
• Arc-extinguishing Medium: SF6
• Installation: Fixed
• Structure: MCB
• Poles Number: 3
• Type: Circuit Breaker
• Function: Conventional Circuit Breaker, Overcurrent Protection
• Certification: ISO9001-2000
• Ambient Temperature: -40ºC-+40ºC
• Altitude: Not Over 3000m
• Power Grid Frequency: 48 ~ 52Hz
• Relative Humidity: Not Higher Than 90% (25ºC)
• Transport Package: Export Box
• Trademark: DGG
• Origin: China
• HS Code: 8535210000
• Production Capacity: 100000PCS/Year
• Package Size: 130.00cm * 100.00cm * 100.00cm
• Package Gross Weight: 120.000kg
• Lead Time: 15 days (1 - 1 Pieces) ; To be negotiated ( > 1 Pieces)

Product Description

PHOTOS OF PRODUCT

GENERAL

In the realm of high-voltage power systems, specifically those operating at 110kV and above, the neutral point direct grounding method is a common practice, known widely as a high current effective grounding system. This method ensures that the transformer's neutral point remains firmly grounded, preventing overvoltage issues and negating the need for additional protection at this point. However, practical applications often necessitate an operation mode where the neutral points of certain transformers remain ungrounded to curtail single-phase short circuit currents, avoid communication interference, and meet specific relay device configuration requirements. Typically, only 30% to 50% of transformer neutral points are allowed direct grounding, safeguarding the system's overall safety and stability. Furthermore, in ring or radial power supply networks, dispatchers strategically manage the power flow by manipulating the neutral points of intermediate terminal transformers to operate in a non-direct grounding mode, aligning with operational requirements. Despite the three-phase symmetry in normal conditions, where the neutral point's potential is zero irrespective of grounding, various factors such as lightning, operational mishaps, and single-phase grounding faults can lead to high overvoltage at the transformer's neutral point, posing potential damage risks which necessitate protective measures.

The electric power industry standard DLT620-1997 concerning Overvoltage Protection and Insulation Coordination for AC Electrical Installations clearly advises against the use of locally ungrounded systems within 110kV and 220kV effectively grounded frameworks. The reasoning behind this is to prevent the generation of excessive power frequency overvoltage. For systems where partial ungrounding is unavoidable, the standard mandates the implementation of overvoltage protection for ungrounded neutral points, particularly those at 110kV and 220kV levels with low-voltage side power supply. This protection is best achieved using a zinc oxide lightning arrester complemented by parallel clearance, effectively safeguarding the system against overvoltage hazards.

Introducing the vacuum circuit breaker series transformer neutral point gap grounding protection complete device, a sophisticated solution crafted by Denggao Electric Co., Ltd. This comprehensive device is meticulously engineered to shield transformers from insulation damage caused by neutral point overvoltage, switching overvoltage, and power frequency transient overvoltage. With this advanced device, you ensure robust protection and enhanced operational reliability for your power systems.

MODEL AND MEANING
USAGE ENVIRONMENTAL CONDITIONS

1. Outdoor Use
2. Ambient Temperature: A range accommodating not lower than -40ºC and not exceeding +40ºC ensures the device's resilience in various climates.
3. Relative Humidity: Capable of withstanding humidity levels not exceeding 90% at 25ºC, ensuring reliable function in moist environments.
4. Altitude: Designed for locations at altitudes up to 3000m, making it suitable for diverse geographical regions.
5. Power grid frequency: Compatible with systems operating between 48 to 52Hz for 50Hz networks and 58 to 62Hz for 60Hz networks, ensuring versatile application.
6. Installation site: The site must be free of chemical corrosive gases, steam, and explosive dust to ensure optimal device performance and longevity.

TECHNICAL SPECIFICATION

number	Project		Unit	Reference
1	Rated voltage		kV	12
2	Rated current		A	630		1250
3	Rated frequency		HZ	50
4	Rated insulation level	1min power frequency withstand voltage	kV	42/48
		Lightning impulse withstand voltage		75/85
		Secondary circuit 1-minute frequency withstand voltage		2
5	Rated short-circuit breaking current		kA	16	20	20	25
6	Rated short-circuit making current (peak value)		kA	40	50	50	63
7	Rated short-time withstand current		kA	16	20	20	25
8	Rated peak withstand current		kA	40	50	50	63
9	Rated short-circuit breaking current breaking times		rate	30
10	SF6 Rated gauge pressure of gas		Mpa	0
11	mechanical life		rate	10000