11kV 15kV 20kV 22kV Three-Phase Oil-Immersed Earthing/Grounding Transformer China Manufacturer

Name: 11kV 15kV 20kV 22kV Three-Phase Oil-Immersed Earthing/Grounding Transformer China Manufacturer
Brand: Wenzhou Rockwell Transformer Co., Ltd.
SKU: 1270
Price: 1.99 USD
Availability: InStock

Wenzhou Rockwell Transformer Co., Ltd.

12yrs + staff 60000+m² US$100000000+ China

Wenzhou Rockwell Transformer Co., Ltd.

12yrs + staff 60000+m² US$100000000+ China

Attributes Description Documentation Resource Library Supplier

Key attributes

Brand	Rockwell
Model NO.	11kV 15kV 20kV 22kV Three-Phase Oil-Immersed Earthing/Grounding Transformer China Manufacturer
Rated frequency	50/60Hz
Rated capacity	500kVA
Series	JDS

Product descriptions from the supplier

Description

Description

Earthing transformers are classified as standard reactors. An earthing transformer (neutral coupler) is a three-phase transformer connected to the power system to provide a neutral connection for earthing, either directly or via impedance. The earthing transformers may, in addition, supply a local auxiliary load.

During single-phase faults, the reactor limits the fault current in the neutral, and the restoration of the power line is improved. According to the IEC 60076-6 standard, the neutral-earthing reactor is connected between the neutral of a power system and the earth to limit the line to earth current under system earth fault conditions to the desired value.

The earthing transformer creates a neutral point for a network. ZN connection is usually applied. Z connection provides linear and specified zero sequence impedance. YN + d can also be applied.

Features

Functional Uniqueness:

Constructing an Artificial Neutral Point: Provides a reliable neutral point connection for systems with ungrounded or high-impedance grounded neutrals (such as IT systems and resonant grounded systems).
Grounding Path Management: The neutral point can be directly grounded or grounded via a reactor/resistor, precisely limiting single-phase ground fault current (in line with IEC 60076-6).

Fault Current Control:

Suppressing Fault Current: Limits the ground fault current to a safe valuev by connecting a neutral reactor in series, preventing equipment damage.
Accelerating System Recovery: Reducing the magnitude of the fault current helps the arc self-extinguish, shortens power outage duration, and improves power supply continuity.

Winding Connection Methods:

ZN Type (Zigzag Connection): A mainstream design that provides linear zero-sequence impedance, with strong magnetic circuit balance and anti-saturation capability.
YN+d (Star + Delta): The secondary delta winding can supply auxiliary loads (doubling as a station service transformer function).
Controllable Zero-Sequence Impedance: Impedance values can be customized to ensure precise matching with the system protection strategy.Safety and Standard Compliance:
Following IEC 60076-6: Regulates the temperature rise, insulation, and short-circuit withstand capability of neutral reactors.
Overvoltage Suppression: Limits transient overvoltages caused by ground faults, protecting equipment insulation.

Main Technical Parameters

Some of these earthing transformers cover voltage levels including：3.3kV / 6kV / 11kV / 15kV / 20kV / 22kV / 30kV / 33kV / 34.5kV / 36kV / 44kV / 66kV / 88kV / 110kV / 132kV / 145kV / 150kV / 220kV / 275kV / 330kV / 400kV, etc. The current withstand time ranges from 1s, 2s, 3s, 5s, 6s, 8s, 9s, 10s, 30s, 60s, 1hour to 2hours, and customization is available.

Parameter	Specification
Transformer type	Grounding transformer
Reference standard	IEC 60076
Rated power	500kVA
Rated voltage	11kV
Rated frequency	50Hz
Cooling method	ONAN

Main Application Areas

Industrial Power Distribution: Grounding protection for plant electrical systems in petrochemical, metallurgical, and mining industries
Grid Infrastructure: Neutral grounding retrofits for urban distribution substations and switching stations
New Energy Stations: Grounding systems for grid-connected sides of distributed photovoltaic plants and biomass power generation
Transportation Power: Grounding devices for electrified railway traction substations and metro power supply networks

FAQ

Q: What are the possible causes when the zero-sequence current of an earthing/grounding transformer rises abnormally？

Abnormal rise of zero-sequence current is a typical early warning signal during the operation of earthing/grounding transformers. The core causes are divided into two categories, and troubleshooting must follow the principle of "system first, then equipment": ① System-side causes: The most common is single-phase ground fault in the distribution network (such as insulator flashover of lines, cable damage and grounding), at this time, the zero-sequence current will appear synchronously with voltage imbalance; followed by severe three-phase load imbalance (such as sudden increase of load in one phase) or harmonic zero-sequence current generated by the input of a large number of nonlinear loads (such as frequency converters, electric arc furnaces). ② Equipment-side causes: Local short circuit of earthing/grounding transformer windings (such as loose cross-connection points of zigzag windings), multi-point grounding fault of iron core, or short circuit of auxiliary winding circuit indirectly affecting zero-sequence current monitoring.

Q: How to conduct preliminary troubleshooting when the zero-sequence current of an earthing/grounding transformer rises abnormally?

Preliminary troubleshooting must follow the principle of "system first, then equipment", with steps as follows: Step 1, judge whether there is single-phase grounding through voltage monitoring (voltage rise of non-fault phase, voltage drop of fault phase); Step 2, check recent load changes and operation records of nonlinear loads to eliminate the impact of load imbalance or harmonics; Step 3, disconnect the connection between the earthing/grounding transformer and the system, measure its zero-sequence impedance independently, and if the deviation from the factory value exceeds ±15%, further maintenance of windings and iron core is required.

Know your supplier

Rockwell

Wenzhou Rockwell Transformer Co., Ltd.
12yrs 60000+m² US$100000000+ China

Wenzhou Rockwell Transformer Co., Ltd.

12yrs 60000+m² US$100000000+ China

Online store

On-time delivery rate

Response time

100.0%

≤4h

Company overview

Workplace: 60000m² Total staff: Highest Annual Export(usD): 100000000

Workplace: 60000m²
Total staff:
Highest Annual Export(usD): 100000000

Services

Business Type: Design/Manufacture/Sales

Main Categories: High Voltage Electrical Apparatus/Electric transformer

Whole life care manager

Whole-life care management services for equipment procurement, use, maintenance, and after-sales, ensuring safe operation of electrical equipment, continuous control, and worry-free electricity consumption.

The equipment supplier has passed platform qualification certification and technical evaluation, ensuring compliance, professionalism, and reliability from the source.

Negotiable

Pricing calculator

Model

JDS-500-11

Warranty by

Whole life care manager

The equipment supplier has passed platform qualification certification and technical evaluation, ensuring compliance, professionalism, and reliability from the source.

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