250 kVA Distribution Transformer
A 250 kVA unit is the size most often specified for small factories, commercial buildings, housing estates and light industrial sites. At this rating cast-resin dry-type builds are frequent choices where the unit sits indoors or where fire rules restrict oil. We build it oil immersed or cast resin, in 50 Hz and 60 Hz, to IEC 60076.
Indicative specification
| Power Rating | 250 kVA |
|---|---|
| Primary Voltage | 3.3 / 6 / 10 / 11 / 13.2 / 13.8 / 15 / 20 / 22 / 33 / 34.5 / 35 kV class |
| Secondary Voltage | 480/277 V, 400/230 V, 380/220 V, or customized |
| Phase | Three-phase |
| Cooling Type | AN (natural air) / AF (forced air) on dry-type builds; ONAN on oil-immersed builds |
| Core Material | High-efficiency (CRGO) silicon steel |
| Connection Group | Dyn11, Yyn0, Dyn5 |
| Winding Material | Copper / Aluminium |
| Frequency | 50 / 60 Hz |
| Insulation | Epoxy cast resin (F class 155 °C / H class 180 °C) or mineral oil |
| Tap Changer | ± 2 × 2.5% Off-Circuit Tap Changer (OCTC) |
| Short-circuit impedance | 4.0% (typical) |
| Temperature Rise | Winding rise ≤ 100 K (F class) / ≤ 125 K (H class); oil-immersed: top oil ≤ 50 K, winding ≤ 55 K |
| Noise Level | ≤ 60 dB at 1 meter |
| Enclosure | Hermetically sealed steel tank, weatherproof for indoor and outdoor use |
| Altitude | ≤ 1,000 m or customized |
| Ambient Temperature Range | -30 °C to +50 °C |
| Accessories | Conservator tank, oil level indicator, gas relay, pressure relief valve, etc. |
| Standards Compliance | Designed to comply with IEC 60076, IEEE C57 and ANSI C57 as applicable to the order |
| Applications | Commercial and institutional buildings, industrial facilities, oil & gas, solar and wind energy, utility grid connections, data centers, and coastal islands and high-altitude regions. |
| Transport & Installation | Lifting lugs, skid base, galvanized fittings |
| Warranty | Two years |
| Delivery Time | Typically 30 days, depending on quantity |
| Min. order quantity | ≥ 1 set |
Neighbouring ratings
Is this the right size?
If you know the connected load and the diversity, send both and we will check the rating before you order. Oversizing means paying for capacity that sits idle every hour of the year.
Oil immersed or cast resin?
- Oil immersed: Yes, 250 kVA oil immersed is a standard build.
- Cast resin: Yes, 250 kVA cast resin is a standard build.
- Oil units go outside or in a separate substation room; cast resin units go inside the building.
Where a 250 kVA unit is used
Questions buyers ask
Typically 30 days after drawing approval, depending on the quantity.
Send the connected load, the diversity factor and any planned expansion. We check the load against the rating and tell you whether 250 kVA leaves enough headroom before you order.
Yes. Test report, outline drawing and a terminal diagram go out with the unit.
Usually. Send the old nameplate or the outline drawing and we will check the footprint, terminal positions and loss figures before quoting.
Rating, primary and secondary voltage, frequency, vector group, quantity, application and the ambient conditions. A drawing or a nameplate photo settles the rest.
Send us the specification
Rating, primary and secondary voltage, frequency, quantity and the application. We answer within one working day.
Email info@xsdfftransformer.com · WhatsApp +852 54162620