Core
The core is made of high-permeability cold-rolled grain-oriented silicon steel and features a step-lap lamination structure. The cross-section of the core limb is a multi-step circular shape, uniform with the cross-section of the yoke.
Winding
The windings adopt corrugated oil ducts utilizing a non-impregnation process and are bound with shrinkable tape; all windings are concentric coils. Taps of the high-voltage winding shall have corresponding tap voltages and be led out to a tap changer, which shall be mounted on the tank cover. When changing the tapping voltage, the power supply must be disconnected first.
Installation of Protective Devices
All transformer capacities are equipped with a pressure relief valve.
A gas relay with alarm and trip terminals can be provided upon request.
Oil Temperature Indication Deviation
All transformers are equipped with a pocket for a glass-stem thermometer, which is mounted on the tank top and immersed in the oil approximately 120 ± 10 mm.
Transformers rated 1000 ~ 2000 kVA are equipped with an outdoor signal thermometer.
Transformer Tank
The transformer tank features a corrugated wall, with a powder-coated surface that is reinforced with film. The corrugated radiators not only serve a cooling function but also act as a "breathing" mechanism; their elasticity allows them to accommodate oil volume changes caused by temperature variations. Consequently, this eliminates the need for a hermetically sealed protection, which also reduces the overall height of the transformer.
The transformer adopts vacuum oil filling technology during the sealing process to completely remove moisture from the transformer and prevent contact between the transformer oil and air. This technique also avoids deterioration of insulating properties or oil aging caused by the ingress of oxygen or moisture, thereby enhancing the operational reliability of the transformer.
Main Technical Parameters


Service Conditions
Installation Altitude: The altitude must not exceed 1000 m.
Ambient Temperature: -40 ℃ ~ 40 ℃.
Dimension Selection


Ordering Guide
Please specify in the order the product model, rated capacity, HV/LV rated voltage and high-voltage tapping range, number of phases, frequency, connection symbol, etc.
Packaging and Transportation
Packaging Details: Standard export packing
Port of Delivery: Shanghai or Ningbo

S9/10/11/13/20/22 35 kV Sealed Oil-Immersed Power 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.