Intelligent Protection Device for 12kv Vacuum Circuit Breaker Systems

• Customization: Available
• Breaking Capacity: High Voltage Circuit Breakers
• Operation: Manual Type
• Model NO.: ZN63-12
• Speed: Normal Type Circuit Breaker
• Arc-extinguishing Medium: Vacuum
• Installation: Fixed
• Structure: MCB
• Poles Number: 3
• Type: Circuit Breaker
• Function: Conventional Circuit Breaker, Overcurrent Protection
• Certification: ISO9001-2000
• Ambient Temperature: -40℃-+40℃
• Altitude: Not Over 3000m
• Power Grid Frequency: 48 ~ 52Hz
• Relative Humidity: Not Higher Than 90% (25℃)
• Transport Package: Export Box
• Trademark: DGG
• Origin: China
• HS Code: 8535210000
• Production Capacity: 100000PCS/Year
• Package Size: 800.00cm * 500.00cm * 600.00cm
• Package Gross Weight: 200.000kg

Product Description

PHOTOS OF PRODUCT

GENERAL

In the world of high voltage power systems, particularly those rated at 110kV and above, a strategic choice is made: to directly ground the neutral point, or not. Known as a high current effective grounding system, this direct approach ensures no overvoltage issues at the neutral point. However, the dynamic nature of power systems often necessitates a shift; limiting single-phase short circuit current, preventing communication disruptions, and fulfilling relay device settings and configurations. Thus, some transformers operate with ungrounded neutral points, striking a balance where only 30% to 50% of transformer neutral points are grounded directly. This ensures the system operates safely and securely. Additionally, power networks-whether ring or radial-are managed with precision, allowing dispatchers to direct power flow by strategically deciding which transformer neutral points operate without direct grounding. Under normal operational circumstances, three-phase symmetry keeps the neutral point potential at zero, negating the need for overvoltage protection. However, the system isn't immune to disturbances like lightning, operational refusals, disconnections, or single-phase grounding faults. Such events can elevate the neutral point's overvoltage, risking damage and necessitating protective measures.

According to the stringent electric power industry standards, specifically DLT620-1997, overvoltage protection and insulation coordination for AC electrical installations are critical. The standards caution against local ungrounded systems in 110KV and 220KV effectively grounded systems to prevent excessive power frequency over-voltage. For these partially ungrounded systems, the recommended strategy for over-voltage protection at ungrounded neutral points, supplied from low-voltage sides, is to employ zinc oxide lightning arresters in tandem with parallel clearance.

Our company proudly presents the DGNPD series-a comprehensive transformer neutral point gap grounding protection device tailored for safeguarding transformer neutral point insulation against overvoltage. This complete device is a frontline defender against transformer overvoltage, switching overvoltage, and power frequency transient overvoltage, ensuring resilience and reliability.

MODEL AND MEANING


USAGE ENVIRONMENTAL CONDITIONS

1. Designed for Outdoor Use
2. Ambient Temperature Range: A robust tolerance from a chilly -40ºC to a warm +40ºC
3. Relative Humidity: Maintained below 90% at a cozy 25ºC
4. Operational Altitude: Efficiently functions at heights not exceeding 3000 meters
5. Power Grid Frequency Compatibility: 48 ~ 52Hz for 50Hz systems, and 58 ~ 62Hz for 60Hz systems
6. Installation Site Requirements: The environment must remain free from chemically corrosive gases, steam, and explosive dust, safeguarding the integrity of the installation.

TECHNICAL SPECIFICATION

number	project		unit		Reference
1	rated voltage		kV		12
2	Rated insulation level	1-minute industrial frequency withstand voltage			42(break48)
		Lightning Impact Withstand Voltage			75(break85)
3	Rated frequency		Hz		50
4	rated current		A		630 1250	1250	1600
						1600	2000
						2000	2500
						2500	3150
5	Rated short-circuit breaking current		kA		20;25	31.5	40
6	Rated short-circuit closing current				50;63	80	100
7	Rated short-circuit breaking current times		rate		50		30
8	Rated short circuit duration		s		4
9	mechanical life		rate		30000
10	Rated sequence of operation				O-0.3s-CO-180s-CO
11	Rated short-circuit breaking current breaking times		rate		50
12	Rated closing voltage of actuator		V		AC110 AC220 DC110 DC220
13	Rated switching voltage of actuator		V		AC110 AC220 DC110 DC220
14	contact opening distance		mm		11±1
15	Overtravel (contact spring compression length)		mm		3
16	Three-pole closing and closing non-simultaneity		ms		≤2
17	Contact closure bounce time		ms		≤2
18	Average gate opening speed		m/s		0.9~1.3
19	Average closing speed		m/s		0.4~0.8
20	opening time		ms		20~50
21	Closing time		ms		30~70
22	Main circuit resistance		μΩ		≤50		≤35
23	Allowable wear cumulative thickness of movable and static contacts		mm		3