MCCB Vacuum Circuit Breaker with Outdoor Load Break Switch

• Customization: Available
• Breaking Capacity: High Voltage Circuit Breakers
• Operation: Manual Type
• Model NO.: FZW28-12F
• Speed: Normal Type Circuit Breaker
• Arc-extinguishing Medium: Vacuum
• Installation: Fixed
• Structure: Vacuum Load Switch
• 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: 820.00cm * 820.00cm * 450.00cm
• Package Gross Weight: 200.000kg
• Lead Time: 15 days (1 - 1 Pieces) ; To be negotiated ( > 1 Pieces)

Product Description

ILLUSTRATIVE GALLERY OF THE PRODUCT

PRODUCT OVERVIEW

High-voltage power systems, specifically those rated at 110kV and above, traditionally utilize a direct grounding method for the transformer's neutral point. This is often referred to as a high current effective grounding system. In this configuration, the transformer's neutral point is directly grounded, which mitigates concerns related to overvoltage and protection of the neutral point. However, to address operational needs such as limiting single-phase short circuit current, reducing communication interference, and configuring relay device settings, a significant number of transformers are operated with ungrounded neutral points. Typically, only 30% to 50% of transformer neutral points are directly grounded to maintain system safety and stability. Additionally, on certain ring or radial power supply networks, operators may control power flow direction and deliberately set the neutral point of an intermediate terminal transformer to function in a non-direct grounding mode as per operational demands. Generally, in normal system operations with three-phase symmetry, the potential at the neutral point remains zero, regardless of grounding, eliminating the necessity for overvoltage protection. However, operational disruptions caused by factors such as lightning strikes, operational errors, mechanical failures, disconnections, and single-phase grounding faults might induce high overvoltage at the transformer's neutral point, potentially causing damage. Thus, protective measures must be employed.

According to the electric power industry standard DLT620-1997 for Overvoltage Protection and Insulation Coordination in AC Electrical Installations, the formation of ungrounded systems should be minimized in effectively grounded systems operating at 110KV and 220KV, to avoid excessive power frequency over-voltages. For these partially ungrounded systems, the over-voltage protection mechanism for 110kV and 220kV ungrounded neutral points on systems that supply power at the low-voltage side should integrate the use of zinc oxide lightning arresters alongside parallel clearance methods.

Our Vacuum circuit breaker series, a comprehensive transformer neutral point gap grounding protection device, offers a robust solution designed to shield against potential damage resulting from transformer neutral point insulation breakdowns, switching surges, and transient power frequency overvoltage.

MODEL IDENTIFICATION AND SIGNIFICANCE

ENVIRONMENTAL OPERATING CONDITIONS

1. Optimized for Outdoor Deployment
2. Operational Temperature Range: From a chilly -40ºC to a warm +40ºC
3. Relative Humidity: Not exceeding 90% at 25ºC
4. Suitable for Altitudes: Up to 3000 meters
5. Frequency Range Compatibility: 48 ~ 52Hz for 50Hz systems, 58 ~ 62Hz for 60Hz systems
6. Installation Prerequisites: The environment must be devoid of chemical corrosive gases, steam, or explosive dust particles.

TECHNICAL SPECIFICATIONS

number	project			unit	Reference
1	rated voltage			kV	AC220
2	Input operating voltage frequency			Hz	50
3	Rated insulation level	Lightning Impact Withstand Voltage		kV	75/85(break)
				kV	42/48(break)
		1-minute industrial frequency withstand voltage	dry run
			wet run	kV	34
4	rated current			A	630
5	Rated short-time withstand current and duration			kA/2s	16
6	Rated peak withstand current			kA	40
7	Rated short-circuit closing current			kA	40
8	mechanical life			rate	10000
9	net weight			kg	210
10	operating voltage			v	AC220
11	Input operating voltage frequency			Hz	50
12	Permissible fluctuation range of input working voltage				±20%
13	Power Consumption			w	<10
14	Sampling phase current input value			A	120~600
15	Low Voltage Action Value			V	10~140
16	Allowable sampling error of current input value				±5%
17	Overcurrent protection action delay time value			s	0.3~1
18	Zero sequence current fixed value			A	0.2~4
19	Grounding action delay time			s	0~1800