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20KV Oil-immersed Distribution Transformer

Oil-Immersed Distribution Transformer — OEM/ODM & Wholesale Supplier

The 20kV oil-immersed distribution transformer delivers dependable, low-loss distribution for industrial and utility networks, rated 30kVA–2500kVA with ONAN cooling. Manufactured by Subian Electric, it serves real estate, petroleum, metallurgy, chemical and light industries. Supplied directly from our manufacturing base in Xuzhou, China, this product is available for distributors and OEM customers worldwide.

20kV — Oil-Immersed Distribution Transformer20 kV · 30–2500 kVA · ONAN
ONAN Cooling
20 kV
Low Loss

Key Specifications

  • Rated Working Voltage — 20 kV
  • System — AC 50 Hz
  • Power Rating — 30 – 2500 kVA
  • Cooling — Oil-immersed, ONAN
  • Construction — Corrosion-resistant steel tank
  • Application — Industrial, real estate, utilities
  • Standards — IEC 60076 / GB 1094

Product Overview

Industrial-Grade Oil-Immersed Distribution Transformer from Subian Electric’s Xuzhou Factory

20kV oil-immersed distribution transformers are designed for industrial applications like real estate, oil, metallurgy, chemicals, and light industries operating on 20 kV frequency of 50 Hz AC. Thanks to its tank resistant to corrosion, oil cooling and low-loss design, it offers stable and reliable power transport in difficult conditions.

20KV Oil-immersed Distribution Transformer — Applications & circuit protection applications

Applications & circuit protection

This transformer is appropriate for industries and electricity distribution networks where dependable 20kV step-down changes are necessary.

  • Industries: Oil, metal and chemistry.
  • Construction: Building and extensive supply.
  • Light industry: Manufacturing and conversion.
  • Utilities: 20kV distribution systems.
20KV Oil-immersed Distribution Transformer construction and operating reliability

Construction & operating reliability

The efficient performance and reliable operation of the equipment is guaranteed by using corrosion-resistant steel tank design, system of oil cooling characterized by self-circulation and the core design having a long-life experience.

  • Self-circulating oil cooling system.
  • Corrosion-resistant steel tank.
  • Core and winding design with minimum losses.
  • Constant output under work load in industrial environments.
  • Reliable operation in hard conditions.

Technical Parameter

Parameter Value
Rated capacity range 30-2500 kVA
Voltage combination (HV) 20 kV
Tap range ±5% / ±2×2.5%
Voltage (LV) 0.4 kV
Connection group Yyn0 / Dyn11 / Yzn11
No-load loss (typical range) 100-2800 W
Load loss (typical range) 690-29000 W
No-load current (typical range) 0.5-2.1%
Short-circuit impedance 5.5%
Rated voltage 20 kV (primary)
Rated capacity 30 – 2500 kVA
Rated frequency 50 Hz
Cooling method ONAN (oil natural, air natural)
Application Industrial and utility distribution
Standard IEC 60076 / GB 1094

Transformer Cost Factors & How to Get a Quote

The ultimate cost of an oil-cooled distribution transformer will rely on the power / capacity in kVA., the input & output voltages, the levels of impedance and losses, the method of cooling, the type of tap changer and any functional accessories. We can provide customer indicative price ranges and issue official quotations in just one working day for regular specifications. Dealers may request our current price list.

  • Standard product series prices according to our standard price list
  • Custom voltage / loss levels depending on project
  • Transport and insurance costs depend on final destination

How to Connect This Transformer

Make certain that tap position is correct for supply voltage before turning on the Oil-Filled Distribution Transformer and that connection group is appropriate as well. The HV caps are connected on the side of supply and the LV terminals on the side of the load. Earth terminals need to be connected in accordance with the local regulations.

  • Confirm tap position with supply voltages
  • Connect HV and LV terminals
  • Connect earthing terminal according to local rules

This Transformer vs. Alternative Ratings

Compare typical configurations to select the correct rating:

Item This Product Smaller / Larger Option
Capacity As specified on this page Lower or higher kVA available
Voltage As specified Other primary voltages available
Impedance Per standard / custom Adjusted to network requirements
Cooling ONAN or AN/AF per type Forced cooling option on request
Application Distribution / power Industrial, renewable or utility

Export Markets & Country Compatibility

We provide Oil-Immersed Distribution Transformer to distributors, power companies and project customers throughout Asia, Africa, Middle East, Latin America and Europe. We check the necessary voltage, frequency, connections and certification for every destination before production.

Transformer Dimensions, Weight & Packing

The dimensions and weight depend on capacity, voltage, and the type of transformer. Generally, approximate values for distribution transformers are as follows: transformers with ratings of 100 kVA have external dimensions ranging from 1000 mm to 1200 mm long, from 500 mm to 700 mm deep, and from 1100 mm to 1400 mm high. The approximate weight of such units is 600 kg to 900 kg. Larger ratings will vary accordingly. The exact dimensions are confirmed with the customer at the ordering stage, and transformers are packed for the mode of transportation.

  • Dimension drawings presented for the customer’s approval before manufacturing begins
  • Packing is done according to shipping standards with lifting points specified
  • The customer is requested to inform about the mode of transportation and destination port

20KV Oil-immersed Distribution Transformer standards and certifications

Standards & certifications

Fabricated under IEC 60076 and GB 1094, this transformer comes with type test reports for project clearance.

  • Design code: IEC 60076/GB 1094.
  • Documentation of type test and routine test reports is available.
  • Good low loss design confirmed.
20KV Oil-immersed Distribution Transformer OEM and B2B supply support

OEM & B2B supply support

Subian Electric is a reputable manufacturer of power equipment supplying equipment to industrial or individual customers, wholesalers and distributors of electrical products and services.

If you need help with regard to certain voltage or capacities or special variants of units, please reach out to us.

  • Prototype samples and drawings are available.
  • Minimum order quantities are not necessary.
  • Original equipment manufacturing and product development are offered.
  • Private labelling and unique packaging options are offered.
  • Technical documentation and certifications are issued.


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Frequently Asked Questions

What is this transformer used for?

It reduces 20kV of primary voltage for utility and industrial distribution purposes.

What capacities are available?

The transformer can handle power ratings between 30 and 2500kVA at 20kV and 50Hz.

What cooling method is used?

ONAN (Oil Natural Air Natural) cooling gives easy and effective heat dissipation.

Do you provide test reports?

Yes, we do have test reports available for this project including type test reports and routine test reports.

Subian Electric Power manufacturing facility in Xuzhou
Manufacturing Base

Oil-Immersed Transformer Production in Xuzhou

Subian operates a 30,000-square-metre facility in Xuzhou, Jiangsu, dedicated to power and distribution equipment. For oil-immersed transformers, our plant covers coil winding, core stacking, tank fabrication, vacuum drying and oil-filling lines, so every unit is produced and tested in-house before delivery. In-house production and testing of the Oil-Immersed Distribution Transformer follow the same controlled process at this facility. A distribution transformer sits in the middle of your network — sound insulation design and quality materials keep it running through load variation and weather. Voltage combination, tap range, connection group and loss level can be matched to your network and load, not just a fixed catalogue.
  • Complete oil-immersed transformer production chain, from coil to tank
  • Technical communication for distributors, EPC contractors and project owners
Factory Facilities

Winding, Tank and Oil Treatment Areas

The images below show the coil winding line, tank welding and assembly stations, and customer inspection activities for oil-immersed transformers at our Xuzhou plant. The Oil-Immersed Distribution Transformer supplied on this page is manufactured, tested and quality-checked at this site. HV/LV coils wound on controlled machines with insulation per drawing. Buyers can inspect units and review records at the plant.
Subian oil-immersed transformer winding workshop
Coil windingHV/LV coils wound on controlled machines with insulation per drawing.
Transformer tank assembly line inside the Subian factory
Final testingRatio, losses and insulation verified on the test bench.
International customer inspecting an oil-immersed transformer at the factory
Customer visitsBuyers can inspect units and review records at the plant.
Manufacturing Process

From Core Stacking to Vacuum Oil Filling

Oil-immersed transformer production follows a controlled sequence: core cutting and stacking, coil winding and drying, core-coil assembly, tanking, vacuum oil filling and final routine testing. Manufacturing of the Oil-Immersed Distribution Transformer follows the confirmed specification, with checks recorded at each relevant stage. Deal directly with the manufacturer for clear pricing, production updates and delivery planning, with OEM and distributor programs available. Order straight from the manufacturer — the price you discuss is the factory price, with volume terms for larger orders
  • Core laminations cut and stacked to the approved design
  • Coils dried in a vacuum oven before tanking
  • Vacuum oil filling and sealed final assembly
Transformer coil winding production line
Delivery & Documents
Transformer core and coil assembly process
Receive Quotation & Drawings
Technician carrying out transformer winding work
Material preparationSteel, copper and insulation inspected to the approved bill of materials.

Insulation, Drying and Oil Treatment

Insulation paper and pressboard are applied to confirmed drawings, windings are vacuum-dried, and treated insulating oil is filled under vacuum to keep moisture and gas within specification. Yes — voltage, tap range, connection group, impedance and accessories can be adjusted and confirmed on drawings. Packing and shipping are planned around unit size and transport method, with terms agreed per order. Yes. We configure voltage combinations and tap ranges to your requirement and confirm
Transformer core manufacturing detail
Packing, loading and shipping documents are arranged with you.Our export team replies with pricing, lead time and technical drawings for your confirmation.
Visitors at the Subian power equipment booth
Subian booth at an international electrical exhibition
Subian team meeting a customer at an electrical exhibition
Customer visiting the Subian transformer booth
Subian international exhibition team
Subian sales representative discussing a project with a visitor
Visitors at the Subian power equipment booth
Subian booth at an international electrical exhibition
Customer Meetings

Transformer Selection Talks at Exhibitions

Our export and engineering teams meet distributors, contractors and project buyers at electrical industry exhibitions to discuss voltage levels, capacity, tap range, standards and delivery schedules for oil-immersed transformers. Extending and upgrading distribution in utility programs where units stay in service for decades. Step-down and step-up duties in medium-voltage distribution systems. Feeding distribution networks where steady voltage regulation and low losses directly affect
Contact Our Export Team
Product Documentation

Transformer Certificates, Test Reports and Shipping Records

For each oil-immersed transformer order we confirm the applicable type-test report, routine test record, certificate and packing list with the buyer before shipment. For the Oil-Immersed Distribution Transformer, certificates, type-test reports and routine test records can be confirmed before ordering. Yes. OEM and ODM supply includes custom nameplates, packaging and documentation for distributors and brands. Every unit is routine-tested at our factory — ratio, losses, impedance, insulation and oil checks — and the test report accompanies the unit. Factory i
Example transformer conformity certificate
Conformity certificates
Example English transformer type test report
Type-test reports
Packed Subian power equipment prepared for delivery
Packing and shipmentTransformers are packed with confirmed lifting points, oil-level checks and transport method for safe delivery.
Product Inquiry

Request Product Information and Pricing

Please provide the product type, rated voltage, capacity, quantity, applicable standard, delivery country and required delivery date. We will reply with a quotation or a list of points requiring confirmation.
  • Product selection and technical clarification
  • OEM, ODM and private-label requirements
  • Quantity, packing and delivery planning

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