Technical Specifications
| Parameter | Value |
|---|---|
| Rated Capacity | 30 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 determined in the manufacturing process — particularly in the epoxy casting and curing stages that no amount of surface inspection can substitute for. The following images document the actual production steps at Zhongxin General’s Sichuan facility for the 30 kVA unit.
Epoxy Vacuum Casting and Curing
The high-voltage winding is vacuum-cast with filled epoxy resin. This process removes air from the winding structure before resin injection, virtually eliminating partial discharge and ensuring uniform dielectric strength throughout the coil. DMD epoxy resin pre-impregnated cloth is used between winding layers for the LV foil winding, providing interlayer insulation and bonding. 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 under controlled temperature profiles.
HV Winding Demoulding
Following completion of the curing cycle, a skilled technician carries out the demoulding operation. The clean, void-free resin surface visible on the finished coil is the direct result of the vacuum casting process. This encapsulation gives SCB-series cast resin transformers their core operating characteristics: flame-retardant, fire-proof, maintenance-free, pollution-free, and capable of operating reliably in humid or contaminated environments where oil-immersed units would require additional protection.
Preliminary Assembly
With casting and curing complete, the transformer enters the assembly stage. The iron core and HV/LV coil assemblies are brought together, structural clamping components are fitted, and the unit is staged for routine factory acceptance testing before surface treatment. The iron core uses imported high-quality cold-rolled grain-oriented silicon steel sheets with a five-stage full-oblique joint structure, bound with F-class non-woven tape and surface-coated with epoxy resin to reduce no-load loss, no-load current, and core noise.
Final Assembly and Surface Treatment
After passing routine factory tests, the transformer receives its final surface treatment — anti-rust primer and finish coating — followed by nameplate attachment, terminal labelling, and pre-dispatch inspection. The completed unit shown here represents the standard of finish on every 30 kVA dry-type transformer leaving Zhongxin General’s Sichuan facility.
Temperature Control System
PT100 platinum resistance sensors are embedded 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 or timed fan start/stop function.
Optional functions include analog current output, RS485 serial interface for centralized monitoring and SCADA integration, additional iron core or ambient temperature detection points, and additional active output contacts.
HV and LV Terminal Details
The high-voltage terminal end features off-circuit tap connections providing ±2×2.5% voltage adjustment capability, allowing the transformer to match 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 operation at 10 kV class.
The low-voltage foil winding adopts a structure that solves the axial helical angle problem during wire winding and achieves better ampere-turn balance. LV output copper busbars are connected to the foil winding using argon-protected welding, ensuring minimal contact resistance and high current-carrying reliability.
Applicable Standards and Testing
Every 30 kVA dry-type transformer manufactured by Zhongxin General undergoes a full programme of routine tests before leaving the factory. No unit is dispatched without a complete test report.
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 (conducted 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 (Inspection and Test Plan) documentation can be provided prior to or alongside shipment. Factory Acceptance Test with client witness is supported.
Available Options and Configurations
| Parameter | Standard / Base Option | Other Available Options |
|---|---|---|
| Winding material | Copper | Aluminum |
| HV side voltage | 6 kV, 10 kV | Customizable to match local grid standards |
| LV side voltage | 380 V, 400 V, 415 V, 433 V | Customizable to other values per local grid |
| Frequency | 50 Hz | 60 Hz |
| Energy efficiency grade | (Per GB 20052-2024) Grade 1, 2, or 3 | — |
| Tap changer | ±2×2.5% (off-circuit) | — |
| Protection degree | IP00 (open type) | IP20, IP30 (with metal enclosure) |
| Temperature control | Standard intelligent controller | RS485 / Modbus communication (optional) |
| Cooling method | ANAN (natural cooling) | ANAF (with forced-air fan) |
| High-altitude version | Not applicable | For installations above 1,000 m a.s.l. |
| Special environment version | Not applicable | Tropical, high-humidity, coastal salt-spray |
Export Packaging and Dispatch
For international export, the 30 kVA transformer is secured to a wooden base pallet and enclosed in a reinforced wooden crate meeting ISPM 15 standards. At this capacity, the unit ships as a fully assembled, compact package — straightforward for both sea freight and air freight. A complete documentation package (test reports, operation manual, CE Declaration of Conformity where applicable, packing list) is supplied in a waterproof sleeve.
Typical Applications
The 30 kVA cast resin dry-type transformer is widely deployed in indoor environments where the compact footprint and oil-free, flame-retardant construction are essential. Typical installations include commercial buildings and retail facilities, small industrial and workshop power distribution, agricultural facilities and rural electrification projects, IT rooms and telecommunications equipment rooms, and integration into prefabricated substations for new energy projects. Its EU-compliant energy efficiency options also make it a regular choice for European import projects.
Inquire About 30 kVA Dry-Type Transformer
Need a quotation, technical datasheet, or Factory Acceptance Test arrangement for a 30 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 requirements.
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 for domestic and international projects. The 30 kVA cast resin dry-type transformer described on this page is the entry point of our SCB-series range — the same manufacturing process, the same material standards, and the same testing protocol that applies across the full capacity range up to our 1,250 kVA units shipped 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.
