| Oil Immersed Electric Transformer Accessories: |
| Accessories Can Be Customized According To Your Requirements |
| HV bushing(Primary bushings) | Radiator |
| LV bushing(Secondary bushings) | Oil tank |
| Tap Changer | Oil temperature indicator |
| Oil Level Indicator | Temperature detector |
| oil release valve | Pressure Relief Valve |
| Rating plat | Wheels |
| Earthing terminal | Lifting lugs |
| S13 type Oil-Immersed Distribution Transformer Parameters, Efficiency Level 3 |
| Rated Power(kVA) | High Voltage(V) | Low Voltage(V) | Connection Symbol | Loss(W) | Short Circuit Impedance (%) |
| No-load Loss | On-load Loss |
| 30 | 6 6.3 10 10.5 11 | 0.4 | Yyn0 Dyn11 | 80 | 630/600 | 4.0 |
| 50 | 100 | 910/870 |
| 63 | 110 | 1090/1040 |
| 80 | 130 | 1310/1250 |
| 100 | 150 | 1580/1500 |
| 125 | 170 | 1890/1800 |
| 160 | 200 | 2310/2200 |
| 200 | 240 | 2730/2600 |
| 250 | 290 | 3200/3050 |
| 315 | 340 | 3830/3650 |
| 400 | 410 | 4520/4300 |
| 500 | 480 | 5410/5150 |
| 630 | 570 | 6200 | 4.5 |
| 800 | 700 | 7500 |
| 1000 | 830 | 10300 |
| 1250 | 970 | 12000 |
| 1600 | 1170 | 14500 |
| 2000 | 1360 | 18300 | 5.0 |
| 2500 | 1600 | 21200 |
Customization Options – 30kVA Oil-Immersed Transformer
Tianya's 30kVA three-phase oil-immersed transformer can be fully customized to meet specific operational and environmental requirements. Available options include a choice of insulating oils—such as mineral oil or eco-friendly FR3—for enhanced sustainability and compliance.
The voltage transformer can be equipped with an on-load tap changer (OLTC) to maintain stable output voltage under fluctuating load conditions. For enhanced safety and functionality, optional features include DMCR protection relays, surge arresters, and pressure relief devices.
To ensure long-term durability in harsh environments, corrosion-resistant coatings and weatherproof enclosures are also available. These flexible customization options make the electrical transformer suitable for a wide range of demanding applications, combining reliability, safety, and efficiency.
Process Testing
Tianya's 30kva Oil Lmmersed Transformers undergo strict quality control throughout the manufacturing process. For the 30kVA model, process testing is conducted at various production stages to ensure compliance with all design and performance standards.
Key tests include verification of core insulation, winding resistance, and dielectric strength. Critical electrical components—such as bushings, tap changers, and protection devices—are also tested to confirm proper operation.
Additionally, the transformer is evaluated for its ability to withstand operational loads and voltage fluctuations. Any issues identified during testing are promptly corrected before final inspection. These rigorous process tests guarantee the transformer's safety, reliability, and compliance with industry standards under real-world operating conditions.
Design Testing
All transformers undergo a comprehensive series of design tests upon completion of production to verify performance and compliance with technical standards. The following test items are included:
· Insulation Power Factor
· Turns Ratio, Polarity, and Phase Relationship
· Winding Resistance
· Impulse Tests
· Load Loss Test (On-Load)
· No-Load Loss Test
· Leak Test
· DC Insulation Resistance Test
· Transformer Turns Ratio (TTR) – All Tap Voltages
· Impedance Voltage & Load Loss at Rated Voltage
· Polarity and Phase Relation (Single-Phase & Three-Phase)
· Excitation and No-Load Loss at Rated Voltage
· Applied Voltage Test
· Induced Voltage Test
· Lightning Impulse Test
· Insulation Resistance at Rated Voltage
· Temperature Rise Test
· Dielectric Withstand (Hi-Pot) Test
These rigorous tests ensure the transformer's electrical, thermal, and mechanical reliability under rated operating conditions.
Routine Test – Winding Resistance
| Category | Details |
|---|
| Purpose of Testing | To verify the continuity and connection quality of internal windings. Detects faults such as open circuits, poor contacts, or localized heating. |
| Testing Equipment | - Winding resistance tester (e.g., OMICRON, DV Power, Raytech, Megger, ISA)
- Test voltage source (6V, 10V, 20V, 40V, or 100V)
- Temperature & humidity meter |
| Pre-Test Preparation | - Ensure test instrument calibration
- Disconnect test object from external circuits
- Select appropriate voltage and set according to equipment specs |
| Test Procedure | Connect Equipment: Securely connect test leads to winding terminals and ensure proper grounding
Apply Voltage: Choose suitable test current based on winding type
Measure & Record: Document resistance (Ω), test voltage (V), current (A), and temperature before and after test |
| Temperature Correction | Convert measured resistance to standard reference temperature (usually 20°C) using a correction formula to ensure accurate comparison |
| Repeat Testing | Test each winding phase separately (HV, MV, LV) and record corresponding resistance values |
| Evaluation Criteria | - Deviation < 5%: Normal
- 5% ≤ Deviation < 10%: Warning
- Deviation ≥ 10%: Further inspection or corrective action required |
S13 Three Phase Oil Immersed Transformer Model Data
The following values reproduce the current S13 Efficiency Level 3 selection schedule. They are suitable for preliminary model comparison but do not replace the guaranteed technical data supplied with the quotation.
| Rated Power (kVA) | HV Options (kV) | LV (kV) | Vector Group | No-Load Loss (W) | Load Loss (W) | Impedance (%) |
|---|
| 30 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 80 | 630 / 600 | 4.0 |
| 50 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 100 | 910 / 870 | 4.0 |
| 63 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 110 | 1,090 / 1,040 | 4.0 |
| 80 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 130 | 1,310 / 1,250 | 4.0 |
| 100 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 150 | 1,580 / 1,500 | 4.0 |
| 125 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 170 | 1,890 / 1,800 | 4.0 |
| 160 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 200 | 2,310 / 2,200 | 4.0 |
| 200 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 240 | 2,730 / 2,600 | 4.0 |
| 250 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 290 | 3,200 / 3,050 | 4.0 |
| 315 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 340 | 3,830 / 3,650 | 4.0 |
| 400 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 410 | 4,520 / 4,300 | 4.0 |
| 500 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 480 | 5,410 / 5,150 | 4.0 |
| 630 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 570 | 6,200 | 4.5 |
| 800 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 700 | 7,500 | 4.5 |
| 1,000 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 830 | 10,300 | 4.5 |
| 1,250 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 970 | 12,000 | 4.5 |
| 1,600 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 1,170 | 14,500 | 4.5 |
| 2,000 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 1,360 | 18,300 | 5.0 |
| 2,500 | 6 / 6.3 / 10 / 10.5 / 11 | 0.4 | Yyn0 / Dyn11 | 1,600 | 21,200 | 5.0 |
Note: Slash-separated load-loss values are retained from the published product schedule. Confirm the applicable conductor, temperature basis and guaranteed loss value with Tianya Electric before procurement.
Design Features That Protect Long-Term Performance
Precision CRGO Core
High-permeability cold-rolled grain-oriented electrical steel and a carefully controlled joint structure create an efficient magnetic path. Accurate cutting, stacking and clamping help control no-load loss, excitation current and operating noise.
Mechanically Stable Windings
Low-voltage windings use foil or cylindrical structures according to capacity, while high-voltage windings use multilayer cylindrical construction. Balanced ampere-turn distribution, formed supports and secure clamping strengthen the windings against transport vibration and short-circuit forces.
Vacuum Drying and Oil Filling
The core-and-coil assembly is vacuum dried, and the insulating oil is filtered and introduced under vacuum. Reducing residual moisture helps protect dielectric strength and slows insulation ageing.
Hermetically Sealed Corrugated Tank
The corrugated tank fins accommodate oil-volume changes as operating temperature varies. Isolating the oil from outside moisture and oxygen supports stable insulation performance and longer maintenance intervals.
Natural Oil-Air Cooling
ONAN cooling circulates oil through the active part and transfers heat through the tank surface without pumps or fans. This reduces auxiliary components and simplifies routine operation.
Transport-Resistant Assembly
Self-locking fasteners, core-and-coil positioning and reinforced supports limit movement during transport. The final design is checked against the specified lifting, handling and installation arrangement.
Standard Accessories and Custom Options
| Category | Typical Items | Customization Focus |
|---|
| Electrical connection | HV bushings, LV bushings, tap changer and rating plate | Terminal type, orientation, creepage distance and cable interface |
| Cooling and oil system | Corrugated tank or radiator, oil filling and oil release valve | Mineral or ester fluid and site-specific thermal requirements |
| Indication and protection | Oil temperature indicator, oil level indicator, temperature detector and pressure relief valve | Local indication, alarm contacts and monitoring requirements |
| Handling and installation | Lifting lugs, wheels, transformer base and earthing terminals | Pole or ground installation, rail gauge and site layout |
| External finish | Surface preparation and protective coating | Colour, humidity, salt, dust and corrosive environment |
When Is Efficiency Level 3 the Right Choice?
The S13 Efficiency Level 3 model is suitable when the project specification permits this loss class and the buyer is balancing initial equipment cost with dependable distribution performance. The decision should be based on the tender requirement and a lifecycle-loss calculation, not on purchase price alone.
| Option | Best Fit | Procurement Priority |
|---|
| S13 / Efficiency Level 3 | Standard utility, rural, commercial and industrial distribution where Level 3 is accepted | Balanced capital cost and operating performance |
| S20 / Efficiency Level 2 | Projects requiring a lower-loss schedule or stricter energy-performance target | Reduced lifecycle energy loss |
| S22 / Efficiency Level 1 | Long operating hours, high energy costs or tenders specifying the highest available efficiency level | Lowest-loss option within the series |
Efficiency naming and mandatory limits vary by market. Tianya Electric will review the destination standard and the purchaser's guaranteed-loss schedule before confirming a model.
Applications
Urban and Rural Networks
Local substations and feeder systems requiring dependable medium-to-low-voltage distribution.
Factories and Industrial Parks
Power supply for motors, production lines, workshops and plant auxiliary systems.
Mining and Material Processing
Outdoor distribution for concentrated loads where mechanical strength and heat dissipation matter.
Agriculture and Remote Sites
Distribution for irrigation, processing, storage and dispersed loads supplied from medium-voltage feeders.
Commercial and Public Facilities
Ground-mounted substation configurations for buildings, campuses, water facilities and infrastructure.
Renewable-Energy Auxiliary Power
Project-specific step-down supply for solar, wind and energy infrastructure auxiliary loads.
Manufacturing Control and Factory Testing
1. Specification Review
Engineers verify capacity, voltage ratio, load profile, vector group, impedance, loss values, accessories and site conditions before design release.
2. Material and Process QC
Checks cover electrical steel, conductor and insulation materials, followed by inspection during core stacking, winding, active-part assembly, tank fabrication and vacuum processing.
3. Routine Tests
Applicable IEC 60076 and contract tests are completed before shipment. Customer or third-party FAT witnessing can be arranged when agreed at order stage.
4. Documentation and Packing
Approved drawings, technical data, test records and operating documents are prepared with export protection suited to the agreed transport method.
Typical Test Scope
Winding resistance measurement
Voltage ratio and vector-group verification
No-load loss and no-load current measurement
Load loss and short-circuit impedance measurement
Applied and induced voltage withstand tests
Insulation and oil-related checks as applicable
Tank sealing and accessory function inspection
Temperature-rise, impulse, sound-level or other type and special tests are quoted when required by the purchaser's specification.
Why Tianya Electric?
Transformer Manufacturing Since 2007
Tianya Electric developed from a transformer-core factory into an integrated power-equipment manufacturer, bringing magnetic-circuit knowledge directly into complete-transformer production.
Production Capacity for Project Orders
Our published manufacturing profile includes a 20,000 m² site, more than 150 employees, over 30 technical specialists and annual capacity exceeding 6,000 units.
Integrated Production Chain
Core processing, coil winding, tank fabrication, active-part assembly, vacuum treatment, final testing and export packing are coordinated through one manufacturing system.
Engineering and After-Sales Support
We support technical clarification, model selection, drawings, FAT coordination, shipping documentation, installation guidance and operating troubleshooting.
Three Phase Oil Transformer FAQ
How do I select the correct transformer capacity?
Calculate the maximum simultaneous load rather than simply adding every connected load. Then consider load type, motor starting, harmonics, power factor, future expansion, ambient temperature and required redundancy. Tianya Electric can review your load schedule or single-line diagram before recommending a kVA rating.
What is the difference between Yyn0 and Dyn11?
The connection group affects phase displacement, neutral availability, zero-sequence behavior, harmonic performance and protection coordination. Dyn11 is widely used where a grounded low-voltage neutral and improved handling of certain unbalanced loads are required, while Yyn0 may suit other distribution arrangements. The system designer should confirm the required group.
Can the three phase oil transformer use copper windings?
Yes. Both copper and aluminum are available. The choice affects conductor size, transformer dimensions, weight, loss design and price, so it should be stated clearly in the inquiry and technical schedule.
Can you customize voltage and accessories?
Yes. Voltage ratio, frequency, vector group, tap range, impedance, winding material, fluid, terminal arrangement, monitoring devices, coating and installation fittings can be reviewed for the project.
What should be included in an RFQ?
Provide rated capacity, HV/LV voltage, frequency, vector group, tap range, impedance, guaranteed losses, conductor, insulating fluid, applicable standard, installation type, altitude, ambient temperature, accessories, quantity and destination. Attach the single-line diagram and tender specification when available.
What documents can be supplied?
The agreed package can include a technical data sheet, general arrangement and nameplate drawings, routine test report, operation and maintenance manual, packing list and contractually required compliance documents.
Request a Three Phase Oil Transformer Proposal
Send your capacity, voltage ratio, loss requirement, winding preference, service conditions, accessories, quantity and destination. Tianya Electric will review the specification and prepare a project-specific technical and commercial proposal.
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