Q1: What are the key specifications of this 1000 kVA transformer?

Three-phase oil-immersed distribution transformer, 1000 kVA, 10 kV / 0.4 kV, vector group Dyn11, 50 Hz (60 Hz available), ONAN cooling, short-circuit impedance 4.5%. Copper windings on a grain-oriented silicon steel core with step-lap construction. Available in S13 / S20 / S22, with SH15 amorphous alloy optional. Built to IEC 60076, ISO 9001 / 14001 / 45001, CE marked.

Q2: What is the difference between S13, S20 and S22?

They are the three GB 20052-2020 efficiency tiers. At 1000 kVA: S22 = Grade 1 (665 W / 7,415 W), S20 = Grade 2 (745 W / 8,240 W), S13 = Grade 3 (830 W / 10,300 W) — no-load / load loss. S22 cuts total losses by about 28% versus S13. Quick rule: S13 for tight budgets, S20 for mainstream grid projects, S22 where the utility mandates Grade 1 or energy cost is high.

Q3: Is the SH15 amorphous alloy option worth the extra cost?

It depends on load factor. SH15 at 1000 kVA has a no-load loss of only 360 W — 46% lower than S22 (665 W), because amorphous metal has no crystal structure resisting magnetization. It costs 20-30% more. Worth it if your transformer runs below ~30% average load (rural feeders, street lighting, municipal grids, standby duty) — payback in 2-4 years. At high load factors, choose S22.

Q4: How do I confirm this unit is a true drop-in replacement for my aging transformer?

Five points must match the old unit: ① voltage ratio and tap range (10 kV ±2×2.5% vs ±5%); ② vector group (Dyn11 vs Yyn0 — must match exactly for paralleling); ③ impedance (±10% tolerance); ④ footprint, fixing holes and rail gauge; ⑤ cable entry (top vs side). Send us a photo of the old nameplate plus plinth dimensions — we confirm a direct swap before you order.

Q5: Copper windings or aluminium — what is the difference?

Copper has ~60% higher conductivity and better mechanical strength, so copper-wound units are more compact, run cooler and withstand short-circuit forces better, with lower load loss. Aluminium units are 15-25% cheaper but larger and more prone to joint failures over time. For grid replacement and mining/industrial duty, copper (our standard) is the safer choice; aluminium can be quoted where budget dominates and loads are stable.

Q6: Is ONAN natural cooling enough, or do I need fans?

For standard duty up to full rated load, ONAN (natural oil circulation) is sufficient — the corrugated fin radiator dissipates heat without any fan or pump, so there is nothing to fail and no control power needed. If you expect sustained overloading (e.g. >110% regularly) or high ambient temperatures (>40 °C), we can add ONAF fans for a 30-40% capacity boost, or design for a lower temperature rise.

Q7: Should I choose a fully sealed tank or a conservator type?

Fully sealed (corrugated tank) is the default: oil never contacts air, so no oxidation or moisture ingress, no breather maintenance, oil life up to 20 years — ideal for unattended substations and grid replacement. A conservator type with oil level gauge is supplied when your utility specification requires a visible oil level or an oil-surge relay. Tell us your grid code and we match it.

Q8: Which standards does it comply with, and can you adapt to local codes?

IEC 60076 is the design and test baseline, and the unit is CE marked for EU market access, manufactured under ISO 9001 / 14001 / 45001. For export we routinely adapt to ANSI/IEEE C57 (North America, 60 Hz), AS/NZS 60076, GOST (CIS) and utility-specific specs — including different ratios, tap ranges, terminal layouts and fitting lists. Loss tiers follow GB 20052, EU EcoDesign, or your specified kW values.

Q9: Can it be used inside a compact substation, or for PV / wind auxiliary supply?

Yes to both. Its compact footprint and standard dimensions make it a common choice for prefabricated / box-type substations and small indoor substations. For PV and wind auxiliary supply, we supply step-down or step-up versions with the required ratio (e.g. 10/0.4 kV for station auxiliary, or 0.69 kV secondary for inverter duty), plus anti-condensation heaters and higher creepage bushings for exposed sites.

Q10: Which oil grade do I need, and what about lead time and warranty?

Oil grade: #25 (pour point ≈ -25 °C) for most of Europe, Southeast Asia, Middle East and Africa; #45 (≤ -45 °C) for northern Kazakhstan, Siberia and Mongolia — CIS tenders citing GOST 982-80 effectively require #45. Lead time: 25-40 days after drawing approval. Warranty: 24 months from commissioning or 30 months from shipment, whichever comes first; common spares ship within 72 hours.

Export-standard plywood crate or nude packing with waterproof plastic film and steel banding. The transformer is fixed on a steel base frame with lifting lugs. Suitable for sea, air, and land transportation. Gross weight and dimensions will be confirmed in the final packing list.