330 kVA Transformer Manufacturers & Suppliers – Distribution Transformer Factory
Subian Electric is a transformer manufacturer in Xuzhou, Jiangsu, China, with a 50,000-square-metre production base and 350+ employees. The 330 kVA rating is one of the most requested in our distribution transformer range, built for 6kV to 33kV primary networks with a 400V/230V secondary.
Buying factory-direct means manufacturer pricing, a transformer engineered to your voltage and tapping requirements, and a routine test report for every unit produced under ISO9001 and CE controlled processes.
Send your primary voltage, impedance preference and quantity. Our export team will confirm the design, drawings and a quotation with lead time.
Since 2019 · 50,000m² · 350+ Staff
Distribution Transformers We Manufacture
Oil-immersed and dry-type distribution transformers from 30 kVA upward – pole, pad and substation styles – with the 330 kVA rating available in standard and project-specific ratios.
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10kV Dry-Type Transformer-SCBH series Amorphous Alloy
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20-35KV Dry-Type Transformer
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20-35KV SCB Series Epoxy Resin Dry-Type Transformer
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20KV Oil-immersed Distribution Transformer
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35KV Oil-immersed Power Transformer
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6-10KV Oil-Immersed Power Distribution Transformer
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Current Transformer –10KV Indoor High Voltage
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Current Transformer–LMZK Wound Current Transformer300/5a
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Current Transformer–LSY-10 transformer Integrated CT
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current transformer–LXK high voltage zero sequence
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dry type distribution transformer-6-10 KV SCB series epoxy resin cast
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Electrical Transformers–JDZ – 10 Power Voltage
What Is a 330 kVA Transformer?
A 330 kVA transformer is a three-phase distribution transformer rated to pass 330 kilovolt-amperes from a medium-voltage line – commonly 6kV, 10kV, 11kV, 20kV or 33kV – down to the 400V/230V system that powers workshops, farms, residential communities and light industry.
The rating is chosen from the site’s peak demand and expected load growth. Sizing correctly keeps the transformer’s own losses proportionate to the load, holds the secondary voltage within equipment limits, and gives the utility a clean, protectable transformation point that is simple to meter.
- 30 kVA – 63,000 kVA range – with the 330 kVA rating built on standard production lines.
- Oil-immersed or dry-type – ONAN tank units and cast-resin designs from the same factory.
- In-house core and winding – controlled material, vacuum drying and oil filling processes.
- Tested before dispatch – ratio, losses, insulation and dielectric checks per IEC 60076.
- Documentation for approval – test reports, outline drawings and installation manual.
- OEM / wholesale supply – custom nameplates, packaging and container programmes.
Available Build Types
The same 330 kVA rating can be produced in several technologies. Your site and fire rules usually decide the type:
Oil-immersed (ONAN)
the economical standard for outdoor pole, plinth and compact-substation duty, with conservator or fully sealed tank options.
Dry-type (cast resin)
an oil-free 330 kVA transformer for indoor or high-rise locations where fire safety and low maintenance matter.
Amorphous core
a lower no-load-loss version of the same rating for utilities that evaluate transformers on yearly energy cost.
330 kVA Transformer Technical Data
| Parameter | Specification |
|---|---|
| Rated capacity | 330 kVA, three-phase |
| Primary voltage | 6 / 10 / 11 / 20 / 33 kV |
| Secondary voltage | 400 V / 230 V (0.4 kV) |
| Cooling | ONAN (oil) / air-cooled (dry) |
| Vector group | Dyn11 / Yyn0 |
| Impedance | 4% typical, project-adjustable |
| Frequency | 50 / 60 Hz |
| Standard | IEC 60076 / GB 1094 |
Sizing and Loading: kVA, kW and Full-Load Current
Buyers often ask how a 330 kVA unit converts to real power and what current it will carry. The useful power equals the kVA rating multiplied by the load power factor – about 264 kW at the common 0.8 power factor, rising to 330 kW at unity.
Full-load current follows the standard formula I = kVA x 1000 / (1.732 x voltage). At the 400V secondary this is roughly 476 A per phase; on an 11kV primary about 17.3 A; on a 33kV primary about 5.8 A. These figures set the size of the LV cables, breakers and busbars downstream.
To size a transformer from your load, add the connected kW of the equipment, apply a realistic diversity factor, divide by the expected power factor, and add margin for motor starting and growth. If your figure lands between standard ratings, tell us the duty cycle – a short-time overload capability can often bridge the gap economically.
Indicative full-load currents
| Secondary 400 V | approx. 476 A |
|---|---|
| Primary 11 kV | approx. 17.3 A |
| Primary 33 kV | approx. 5.8 A |
| Typical real load at 0.8 pf | approx. 264 kW |
Dimensions, Weight, Colour and Site Planning
Overall dimensions and mass vary with the voltage class, tank type and tapping range, so the drawing issued for your project is the reference. As a guide, an oil-immersed 330 kVA unit for an 11kV/0.4kV service is in the order of 1.5 m long and 1.3 m high to the tank top, with the transport weight roughly between 900 kg and 1,300 kg including oil.
Standard tank finishes are grey (RAL 7032 / 7035 style) and green (RAL 6001 / 6011 style) for outdoor duty; dry-type enclosures are typically light grey with optional RAL colours for indoor panels. Custom colours, anti-corrosion treatment for coastal sites and nameplate layouts can be specified on the order.
Enclosure colour options
| Grey (industrial) | standard outdoor tank and dry-type enclosure finish |
|---|---|
| Green (utility) | common for pole and pad-mounted distribution units |
| Blue / black | available for special projects and branding |
| Coastal protection | higher-grade paint system for marine environments |
New vs Used, Replacement and Delivery
Buyers searching for a 330 kVA transformer sometimes compare new factory units with used or surplus stock. A new unit carries a fresh test report, the full warranty and a design matched to your network; used stock is cheaper upfront but its remaining life, previous loading and oil condition are uncertain unless fully documented.
For a replacement, keep the failed unit’s nameplate data – voltage ratio, vector group, impedance and tapping range – so the new transformer matches the existing protection settings and installation footprint. If you only have the old drawings, our engineers can work from those.
Delivery is confirmed at quotation: production is scheduled against the approved drawing, and packing, marking and shipping are coordinated to your port or project site, with photographs and documents issued before departure.
From Core Steel to a Tested 330 kVA Unit
Core cutting, coil winding, vacuum drying, oil filling or resin casting, assembly and testing are all done in-house, so the 330 kVA unit you receive is traceable from raw material to its test report.
Winding & Core
Controlled winding tension, layer insulation and core stacking give consistent impedance and loss performance.
Vacuum Drying & Oil Fill
Careful drying removes moisture before oil filling, protecting the insulation system for a long service life.
Quality & Testing Center
Every unit is routine-tested; type-test reports support project approval and market certification.
Packing & Delivery
Transformers are protected, marked and dispatched on a coordinated schedule to the port or site.
330 kVA Transformer Price & Factory Quotation
Ask for the current factory price with your primary voltage, impedance and quantity. We confirm the design on drawings and issue a written quotation with lead time – single units and container programmes are both supported.
OEM / ODM & Wholesale Transformer Supply
Distributors can resell the 330 kVA transformer under their own brand, with private-label nameplates, colour, packaging and documentation.
OEM / ODM
Factory-Direct
Custom ratings, tappings and branding built on our standard transformer platforms.
Factory direct · Test docs · Export support
Wholesale Supply
Volume Pricing
Container quantities with mixed ratings and models per shipment.
Factory direct · Test docs · Export support
Distributor Support
Channel Partners
Catalogues, technical support and priority production for channel partners.
Factory direct · Test docs · Export support
Oil-Immersed vs Dry-Type at This Rating
For outdoor distribution duty the oil-immersed 330 kVA unit offers the lowest cost per kVA, proven reliability and simple maintenance, while needing oil containment and periodic oil checks. The dry-type unit removes oil handling and suits indoor installation, at a higher first cost.
Many buyers compare the 330 kVA transformer against the neighbouring 300 kVA and 400 kVA ratings. Because 330 kVA is not a standard IEC preferred value in every market, the choice is often driven by the utility’s approved list or by a calculated load close to that figure – our engineers help you confirm the closest economical rating for your load profile.
How to Compare 330 kVA Transformer Suppliers
Look beyond price per unit. The figures that decide your long-term cost are the no-load and load losses, the core material, whether the windings are copper or aluminium, and the temperature-rise margin under full load.
Check that routine test reports are issued per unit and that type-test evidence exists for the design. Subian publishes its credentials openly: ISO9001, ISO14001, ISO45001, CE and UL certification, a 110 kV transformer type-test report, and a factory you can visit in person or through our VR tour.
A supplier that manufactures rather than trades can also adjust impedance, tappings and bushings for your project – confirm this before ordering, because catalogue-only sellers cannot.
Certifications & Quality Assurance
Our transformer production runs under ISO9001, ISO14001 and ISO45001 management systems, with CE and UL certification and type-test evidence to 110 kV class.
Product Certifications
10 kV Dry-Type Transformer Certificate
35 kV Transformer CB Certificate
35 kV Transformer CE Verification
Transformer CE Certificate
Dry-Type Transformer Test Verification
ISO 14001 Environmental Management
ISO 45001 Health & Safety
ISO 9001 Quality Management
110 kV Transformer Type Test Report
UL Certificate of Compliance
330 kVA Transformer Manufacturers & Suppliers FAQ
Frequently asked questions about the 330 kVA rating, loading and factory sourcing.
What is the load capacity of a 300 kVA transformer?
How much does a 300 kVA transformer cost?
What amperage is a 480V 30 kVA transformer rated for?
Is there a 400 kVA transformer?
What is the difference between kVA and kW on a transformer?
What does full-load current mean for cable and breaker sizing?
Contact Subian
Need the Right Specification?
Tell us your target market, product type, quantity and technical requirements. Our team will help you identify a suitable configuration for your project.