Technical Specifications
| Parameter | Value |
|---|---|
| Rated Capacity | 400 kVA |
| Phases | 3-Phase |
| Frequency | 50 Hz / 60 Hz |
| High Voltage | 10 kV (customizable) |
| Low Voltage | 400 V (customizable) |
| Vector Group | Dyn11 |
| Insulation Class | Class H (175 °C) |
| Temperature Rise Limit | 100 K |
| Cooling Method | ANAN (Air Natural / Air Natural) |
| Installation | Indoor |
| Energy Efficiency | GB 20052-2024 Grade 1 / Grade 2 · EU No. 548/2014 & 2019/1783 Tier 1 / Tier 2 |
| Applicable Standards | GB/T 10228-2023 · GB 1094.1.2-2013 · GB 1094.3-2017 · GB 20052-2024 · IEC 60076-11 |
| Winding Material | Copper (standard) / Aluminium (available on request) |
| Protection Degree | IP00 / IP20 / IP30 (enclosure options) |
Manufacturing Process — From Winding to Dispatch
The quality of a cast resin dry-type transformer is built in at the manufacturing stage. The following images document the actual production steps at Zhongxin General’s Sichuan facility for the 400 kVA unit.
Foil Winding
The low-voltage winding adopts a foil winding structure, solving the axial helical angle problem inherent in wire-wound coils and achieving superior ampere-turn balance. High-quality copper foil is wound by automatic foil winding machine. DMD epoxy resin pre-impregnated cloth is used between winding layers for interlayer insulation. LV output copper busbars are joined to the foil winding using argon-arc protected welding, ensuring minimal contact resistance.
Post-Winding Inspection
After foil winding is complete, a senior technician performs a detailed quality inspection before the coil insulation wrapping stage. This check verifies dimensional accuracy and winding integrity prior to epoxy casting — a step that cannot be repeated once the coil is encapsulated.
Epoxy Vacuum Casting and Curing
The high-voltage winding is vacuum-cast with filled epoxy resin. This process removes air from the winding before resin injection, virtually eliminating partial discharge and ensuring uniform dielectric strength throughout the coil. Glass fiber mesh plates reinforce the inner and outer walls of the HV winding, enhancing mechanical strength and short-circuit withstand capability. After casting, all coils enter a controlled hot-air curing oven where integral forming takes place.
Iron Core Lamination Stacking
A senior technician carries out the iron core lamination stacking process, assembling imported high-quality cold-rolled grain-oriented silicon steel sheets into a five-stage full-oblique joint structure. This geometry reduces no-load loss, no-load current, and core noise relative to a standard butt-joint arrangement. Cores are bound with F-class non-woven tape and surface-coated with epoxy resin for moisture and rust protection.
Factory Acceptance Testing
Every dry-type transformer manufactured by Zhongxin General undergoes a full programme of routine factory acceptance tests before leaving the facility. No unit is dispatched without a complete test report.
Final Assembly and Batch Completion
Final assembly integrates the iron core and HV/LV coil assemblies, installs structural clamping components, fits the temperature control sensors and fans, and makes all busbar and terminal connections. The image above shows several 400 kVA units after completion of both final assembly and routine testing — a typical picture from our production lines.
HV and LV Terminal Details
The high-voltage terminal end features off-circuit tap connections providing ±2×2.5% voltage adjustment capability — five positions in total — allowing the transformer to compensate for local grid voltage variations without on-load interruption. The glass-fiber reinforced epoxy HV winding body provides the insulation clearances and creepage distances required for reliable 10 kV class operation.
The low-voltage foil winding output copper busbars, welded using argon-arc protection, deliver minimal contact resistance and high current-carrying reliability at rated LV output.
Temperature Control System
PT100 platinum resistance sensors are embedded directly in the low-voltage coil during the manufacturing process. These sensors feed into an intelligent temperature controller providing sequential detection and display of three-phase winding temperatures, fault self-diagnosis, hot-spot phase temperature display, over-temperature alarm output (adjustable setpoint), over-temperature trip output (adjustable setpoint), and automatic fan start/stop.
Optional functions include RS485/Modbus serial interface for centralized monitoring and SCADA integration, additional iron core or ambient temperature detection points, and additional active output contacts.
Applicable Standards and Testing
Routine tests (every unit): winding resistance measurement, voltage ratio and vector group verification, no-load loss and no-load current, load loss and short-circuit impedance, induced overvoltage withstand test, separate-source AC withstand test, partial discharge measurement.
Type tests (on representative units; reports available on request): temperature rise test, lightning impulse test.
Special tests (available on request): sound level measurement, short-circuit withstand test.
All tests are conducted in accordance with IEC 60076-11 and GB/T 10228-2023. Test reports and ITP documentation can be provided prior to or alongside shipment. Factory Acceptance Test with client witness is supported.
Dispatch
The transformer ships as a complete, assembled unit — straightforward for both domestic road transport and international sea or air freight. For export orders, Zhongxin General packages the transformer body on a reinforced wooden pallet enclosed in an ISPM 15-compliant wooden crate, with cooling fans and accessories packed separately to prevent transit damage. A complete documentation package — test reports, operation manual, CE Declaration of Conformity where applicable, and packing list — is supplied in a waterproof sleeve.
For a detailed account of an actual international export project involving a dry-type transformer from Zhongxin General’s Sichuan facility, including ITP, FAT witness, CE Declaration, and bolt torque documentation, see how we navigated EU standards compliance on a real 1,250 kVA dry-type transformer export project.
Available Options and Configurations
| Option / Configuration | Available Choices |
|---|---|
| Winding Material | Copper (standard) or Aluminium |
| Voltage Class (HV) | 6 kV, 10 kV; Customizable to match local grid standards |
| Low Voltage (LV) | 380 V, 400 V, 415 V, 433 V, or other values to match local grid |
| Frequency | 50 Hz (standard) or 60 Hz |
| Energy Efficiency Grade (GB 20052-2024) | Grade 1, Grade 2, or Grade 3 |
| Tap Changer | ±2 × 2.5% off-circuit (standard) |
| Protection Degree (Enclosure) | IP00 (standard), IP20, or IP30 (with metalwork enclosure) |
| Temperature Control | Standard intelligent controller; RS485/Modbus communication (optional) |
| Cooling Method | ANAN (standard) or ANAF (with forced-air fan upgrade) |
| Altitude Version | Standard or high-altitude (for installations above 1,000 m a.s.l.) |
| Environmental Version | Standard, Tropical, High-humidity, or Coastal salt-spray |
Typical Applications
The 400 kVA cast resin dry-type transformer occupies a particularly active segment of the indoor power distribution market. Its oil-free, flame-retardant, maintenance-free characteristics make it the standard specification for commercial and industrial buildings where fire safety and environmental compliance are requirements rather than preferences. Typical installation sectors include commercial buildings, hotels, and shopping centres; industrial parks and manufacturing facilities; data centres and IT facilities where zero-oil-spill risk is mandatory; solar PV and wind energy step-up applications; rail transit power distribution; and hospital power infrastructure. For a hospital-scale reference project spanning multiple dry-type transformer capacities from 500 kVA to 2,000 kVA, see our 16,730 kVA intelligent power system delivered for Xinjin District People’s Hospital.
Inquire About 400 kVA Dry-Type Transformer
Need a quotation, technical datasheet, or Factory Acceptance Test arrangement for a 400 kVA cast resin dry-type transformer? Whether you are sourcing for a single installation, a batch order, or an international export project requiring IEC or EU compliance, Zhongxin General’s engineering team can provide specifications, pricing, compliance documentation, and delivery timelines matched to your project.
Tell us your grid voltage, required LV output, frequency, efficiency grade, winding material preference, and any special environmental or installation conditions — and we will configure the right unit for your project.
Contact Us for Price & Datasheet
About Zhongxin General — Dry-Type Transformer Manufacturer and Factory
Zhongxin General (Sichuan Zhongxin General Electric Energy Co., Ltd.) is a China-based manufacturer and factory specialising in oil-immersed power transformers and dry-type power transformers, HV/MV/LV switchgear, prefabricated substations, energy storage systems, and EV charging infrastructure.
Headquartered in Xinjin District, Chengdu, Sichuan Province, the company holds National “Little Giant” Enterprise status — China’s highest SME innovation designation — alongside National High-Tech Enterprise certification.
Our dry-type transformer portfolio covers 30 kVA to 8,000 kVA, configurable to 6 kV, 10 kV, and 35 kV voltage classes, in copper or aluminium winding, to GB, IEC 60076-11, and EU standards. The 400 kVA cast resin dry-type transformer sits at the centre of our most active production range — the same materials, the same manufacturing processes, and the same testing protocols applied across every unit from our smallest to our 1,250 kVA units supplied to European buyers.
Every transformer we manufacture undergoes full routine testing to IEC 60076-11 or GB/T 10228-2023 before dispatch. Test reports are issued as standard documentation with every order.
Browse all case studies to evaluate Zhongxin General as a supplier — from large-scale hospital installations to European export projects and dedicated industrial substations.
