34.5kv-200A/10s, Zig - Zag - N, Oil Type Grounded Transformer Grounding Transformer

• Phase: Three
• Core: Core-type Transformer
• Cooling Method: Oil-immersed Type Transformer
• Winding Type: Two-winding Transformer
• Certification: ISO9001-2000
• Usage: Combined Transformer, Power Transformer, Distribution Transformer
• Frequency Characteristics: Power Frequency
• Shape of Core: EE
• Brand: OEM
• Primary Voltage: 35kv/34.5/33kv/22.9kv/20kv/15kv/13.8kv/11kv/10kv/6
• Short Circuit Current: 100~6000A
• Frequency: 50/60Hz
• Capacity: 50~6500kVA
• Insulation Level: a
• Transport Package: Nake or Wooden Package
• Specification: 6~35KV
• Trademark: CHANGJI
• Origin: Shanghai, China
• HS Code: 8504349000
• Production Capacity: 200/Month

Product Description

Shanghai Changji Electric Co., Ltd. is a professional enterprise specializing in the production of various reactors, power transformers, dry-type transformers, amorphous alloy transformers, special transformers, and box-type substations.

Equipped with modern production facilities, advanced manufacturing processes, and comprehensive testing equipment, the company ensures the production of high-performance products featuring innovative designs, low losses, low temperature rise, low noise, high impact resistance, and strong short-circuit withstand capability.

Core Products: 10kV, 20kV, and 35kV dry-type and oil-immersed reactors

10kV, 20kV, and 35kV oil-immersed transformers

10kV, 20kV, and 35kV vacuum epoxy-cast dry-type transformers

10kV, 20kV, and 35kV non-encapsulated (SG) vacuum pressure-impregnated dry-type transformers

Box-type substations

Additionally, the company can design and manufacture various special transformers according to customer requirements.

For years, the company has adhered to a customer-first philosophy, earning trust and support through a strong commitment to product quality. By continuously improving quality management and pursuing excellence, Zhejiang Changji Electric Co., Ltd. Strives to secure its market position. With full enthusiasm, sincere cooperation, and a win-win business approach, we warmly welcome domestic and international customers to visit, inquire, and discuss potential collaborations!

Our 10 MVA oil transformer is a state - of - the - art electrical device designed to meet the diverse power distribution needs. With a capacity of 10 MVA (10000kVA), this oil - type transformer is a reliable workhorse in the power grid.

The 10 MVA oil transformer operates at a primary voltage of 23kV and a secondary voltage of 13,860V. Its connection group is Ynd11, which is a well - established and widely used configuration in the power industry. This connection group offers several advantages, such as providing a neutral point on the low - voltage side for single - phase loads and better protection against unbalanced loads.

One of the remarkable features of this 10 MVA oil transformer is its dual - frequency operation capability. It can operate at both 50Hz and 60Hz frequencies, making it highly adaptable to different power systems around the world. Whether you are in a region with a 50Hz power grid or a 60Hz one, this 10 MVA oil transformer will perform efficiently.

The oil - type design of the 10 MVA oil transformer is a key factor in its performance. The insulating oil not only provides excellent electrical insulation but also helps in dissipating heat generated during operation. This ensures that the transformer can run continuously without overheating, thereby extending its service life.

1, Product Overview
The 6kV, 10kV, and 35kV power grids in the power system generally adopt a neutral point ungrounded operation mode. The low-voltage side of the main transformer in the power grid is generally connected in a delta configuration, and there is no neutral point that can be grounded. With the continuous expansion of urban power grids and the increasing number of cable outlets, the system's capacitance current to ground increases sharply, and the capacitance current flowing through the fault point after single-phase grounding is relatively large (exceeding 10A). In order to reduce the ground capacitance current during single-phase grounding faults, compensation devices such as arc suppression coils need to be installed at the neutral point of the transformer. Therefore, a neutral point needs to be artificially established to connect the arc suppression coil at the neutral point, reduce the ground short-circuit breaking current, and improve the reliability of the system power supply.
In addition, single-phase grounding is a common fault during the operation of the generator, and the occurrence of arc grounding at the fault point will further expand the insulation damage of the stator winding. The high resistance grounding of the neutral point of the generator can effectively suppress the grounding fault current of the generator, thereby preventing the stator winding of the generator from burning out and reducing the transient overvoltage of arc grounding. For this purpose, our company has developed a motor neutral point grounding resistor cabinet for single-phase grounding faults in motors. It mainly consists of a single-phase grounding transformer and a resistor, which can effectively avoid damage to the generator stator winding and insulation caused by grounding current.

2, Product Features
Our company produces professional 6kV, 10kV, 20kV, and 35kV grounding transformers, including epoxy cast dry-type and oil immersed grounding transformers, as well as single-phase grounding transformers specifically designed for motors.
A. Iron core
High quality cold-rolled oriented silicon steel sheets are used, with 45 ° full diagonal joints. The iron yoke is clamped with a through screw, and the core column is tied with fiberglass tape. The surface of the iron core is sprayed with silicone resin adhesive to prevent moisture, tighten and minimize noise.
B. Winding
Both the inner and outer windings are made of high-quality copper wires, with a segmented cylindrical structure to enhance interlayer insulation. Vacuum drying technology is used, and the formed windings have good electrical performance, high mechanical strength, and low local discharge capacity.
C. Epoxy resin is not filled with vacuum casting for dry-type grounding transformers, which has stronger smoke and water resistance compared to non encapsulated products. The oil immersed grounding transformer adopts a fully sealed structure and uses corrugated fins for heat dissipation to eliminate the oil storage tank. The oil tanks are sealed with oil resistant rubber strips to prevent the transformer oil from coming into contact with air. The transformer oil does not come into contact with air, ensuring the insulation performance and service life of the product. The product has the characteristics of small footprint, beautiful appearance, and maintenance free.
D. Protective device
Oil immersed grounding transformers are equipped with pressure relief valves and gas relays, as well as oil level gauges for easy monitoring of transformer oil levels at any time. The dry-type grounding transformer is equipped with a temperature control device and has remote transmission function, making it convenient to inspect the operating temperature of the product at any time.

3.Main Technical Parameter

Types	SJD Dry or Oil-immersed
Connection group	(ZN (Zigzag), ZNyn, YNd(open), Ii0)
­­Voltage	Up to 36kV
Current	Up to 3000A*
Duty (Seconds)	10/30/60 or others
Cooling Method	ONAN, ONAF, AN, AF
Frequency	50Hz / 60Hz
Installation	Indoor / Outdoor
Ambient Temperature	-40 ºC to 40 ºC*
Standards	IEC 60076-6, IEC60076-1,IEEE
Enclosure Options	Transformer cabinet for any IP degrees with: -CT -VT -Isolation switch

 Note:  Neutral Short time Current I₀=I_G, Neural Zero Sequence Impedance Z₀=Z_phase /3
           ±5% off load tap change switch
           Declare Z₀ before producing if not a self-limiter
           Z₀ tolerance ≤10%
           If a resistor will be connected between the brought out Neutral and ground, choose Z₀ as small as possible, and better make Z₀+R= V_LN/I_G




 
SJD-Dry or Oil-immersed Earthing transformer(Popular products)

Item&Specs.	Ground-fault Current I0	Time	Impedance Z0
SJD-4.16KV/200A-10S	200A	10s	2.4~12.0Ω
SJD-4.16KV/400A-10S	400A	10s	1.2~6.0Ω
SJD-4.16KV/600A-10S	600A	10s	0.8~4.0Ω
SJD-12.47KV/200A-10S	200A	10s	7.2-36.0Ω
SJD-12.47KV/400A-10S	400A	10s	3.6-18.0Ω
SJD-12.47KV/600A-10S	600A	10s	2.4~12.0Ω
SJD-13.2KV/200A-10S	200A	10s	7.6~38.1Ω
SJD-13.2KV/400A-10S	400A	10s	3.8~19.1Ω
SJD-13.2KV/600A-10S	600A	10s	2.5~12.7Ω
SJD-13.8KV/200A-10S	200A	10s	8.0~39.8Ω
SJD-13.8KV/400A-10S	400A	10s	4.0~19.9Ω
SJD-13.8KV/600A-10S	600A	10s	2.6~13.3Ω
SJD-13.8KV/800A-10S	800A	10s	2.0~10.0Ω
SJD-24.94KV/200A-10S	200A	10s	14.4~72.0Ω
SJD-24.94KV/400A-10S	400A	10s	7.2~36.0Ω
SJD-24.94KV/600A-10S	600A	10s	4.8~24.0Ω
SJD-24.94V/800A-10S	800A	10s	3.6~18.0Ω
SJD-24.94V/1000A-10S	1000A	10s	2.8~14.4Ω
SJD-34.5KV/200A-10S	200A	10s	14.1~70.7Ω
SJD-34.5KV/400A-10S	400A	10s	7.0~35.4Ω
SJD-34.5KV/600A-10S	600A	10s	4.7~23.6Ω
SJD-34.5V/800A-10S	800A	10s	34~17.7Ω
SJD-34.5V/1000A-10S	1000A	10s	2.8~14.2Ω

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• Residential Areas: They are used to step down the voltage from the distribution network to a level suitable for household use, providing reliable power supply to homes and apartments.
• Commercial Buildings: In commercial buildings such as offices, shopping malls, and hotels, pad mounted transformers are used to meet the power requirements of various electrical equipment, including lighting, HVAC systems, and elevators.
• Industrial Facilities: For industrial facilities, these transformers can provide the necessary power for machinery and equipment, ensuring smooth and efficient operation of the production process.
  
  In conclusion, 35KV and below pad mounted transformers are reliable, efficient, and versatile electrical devices that play a vital role in the power distribution system. Their advanced design, performance characteristics, and protection features make them an ideal choice for a wide range of applications. Whether it is in a residential, commercial, or industrial setting, the pad mounted transformer provides a safe and stable power supply to meet the diverse needs of the end - users.
• ZSG11-3000/34.5KV-0.415KV pad mounted transformer techincal data sheet