Since the coils of resin-insulated dry-type transformers are encapsulated in epoxy resin, they are non-flammable, fireproof, explosion-proof, maintenance-free, and pollution-free. They feature a compact size and can be installed directly within the load center. Scientific and rational design, combined with advanced casting technology, endows the product with low partial discharge, low noise, and excellent heat dissipation. The transformer is capable of operating continuously for extended periods under air-cooling conditions at 140% of its rated load.Furthermore, the product is equipped with an intelligent temperature controller featuring fault alarms, over-temperature alarms, over-temperature tripping, and a "black box" (event recorder). It also supports connectivity with computers via an RS485 serial interface for centralized monitoring.
Structural Features
Core
The core is made of imported cold-rolled silicon steel sheets and features a step-lap joint structure; the core limbs are bound with Class F single-sided non-woven glass tape.
The core surface is encapsulated with epoxy resin, which reduces the no-load current and core noise.
The clamping frames and fasteners undergo special surface treatment, further enhancing the product's appearance quality.
High-voltage Winding
The high-voltage winding utilizes vacuum casting filled with epoxy resin, which significantly reduces partial discharge and enhances the coil's electrical performance. Both the inner and outer surfaces of the winding are covered with fiberglass mesh reinforcement, increasing the coil's mechanical strength and the product's short-circuit withstand capability; the coil will never crack.
High- voltage Winding
The low-voltage winding adopts a foil structure, which solves axial alignment issues during winding and ensures uniform distribution of ampere-turns along the winding. Meanwhile, axial cooling ducts are incorporated in the coil to improve heat dissipation. DMD resin pre-impregnated fabric is applied between the winding layers to achieve integral solidification molding.
Manufacturing Process
The coils are wound on high-precision winding machines. The low-voltage winding adopts a foil-type winding structure. Larger capacity transformers are equipped with axial cooling ducts. The windings undergo vacuum drying, casting, and solidification processes. All procedures are carried out strictly in accordance with technical requirements under rigorous monitoring and appropriate quality control. This precision manufacturing ensures there are no bubbles or cavities within the castings, guaranteeing high-quality operation of the transformer.
Temperature Control and Air Cooling System
A cross-flow top-blow fan is adopted, featuring low noise, high air pressure, and an aesthetic appearance. It enhances the safety and reliability of the transformer operation
Protective Enclosure and Busbar Connections
The enclosure provides additional protection for the transformer. Optional protective ratings include IP20, IP23, etc. Enclosure materials include cold-rolled steel plates, stainless steel plates, etc. Low-voltage outgoing connections utilize standard busbars; both side outlets and top outlets are available, or special connection modes can be designed for users.


Service Conditions
nstallation Altitude: The altitude must not exceed 1000m.
Supply Voltage Waveform: Approximately sinusoidal.
Symmetry of Multi-phase Supply Voltage: The line voltages of the multi-phase transformer connection shall be approximately symmetrical.
Ambient Temperature: Maximum temperature +40 ℃.
Maximum Daily Mean Temperature: +30 ℃.
Maximum Annual Mean Temperature: +20 ℃.
Minimum Temperature: -30 ℃ (applicable to indoor transformers).
Dimensions Selection:



Packaging and Transportation:
Packaging: Standard export packaging.
Port of Delivery: Shanghai Port, Ningbo Port.




SC(B)9/10/11/12/13 35 kV Epoxy Resin Cast Dry-Type Transformer is supplied by XIAOPAI, a Wenzhou based exporter of power transmission equipment and flexible packaging machinery. Power transmission equipment is designed and manufactured by XIAOPAI; SINSTAR solventless laminating machines are designed and manufactured by SINSTAR and supplied by XIAOPAI as its authorized global distributor.
| Item | Detail |
|---|---|
| CE marking | Electrical panels CE certified |
| Quality system | ISO 9001 certified company |
| Routine test report | Issued for each unit per the relevant IEC standard |
| Type test report | Available on request per model |
| Export packaging | Seaworthy crating with moisture barrier |
| Customs documents | Invoice, packing list, certificate of origin |
| Manuals | English operation and maintenance manual |
| Shipping terms | FOB Ningbo or Shanghai |
Rating, impedance, vector group and tap range are matched to the project specification before quotation, so the unit ordered matches the drawings approved for the site.
Factory acceptance testing before dispatch. Third-party inspection can be arranged on request.
XIAOPAI is the single point of contact after delivery, coordinating technical support and spare parts with the manufacturing side.
Yes. Send the rating, voltage class, impedance and vector group, and XIAOPAI will quote against the specification with drawings.
CE marking, ISO 9001 company certificate, routine test reports, packing list, commercial invoice, certificate of origin and an English operation and maintenance manual.
Normally FOB Ningbo or Shanghai in seaworthy crating, with buyers free to nominate their own freight forwarder.