66kV Power Transformer
Sub-transmission power transformer for industrial main supply, city substations, and regional distribution. OLTC, built to IEC 60076.
Technical Parameters
Standard parameter ranges for this model. Special requirements can be assessed by our engineering team — contact us for custom specifications.
| Parameter | Standard Range |
|---|---|
| Rated capacity | 6.3–100 MVA (typical: 10/16/20/31.5/40/50/63/80/100) |
| Primary voltage | 66 kV (max 72.5 kV) |
| Secondary voltage | 10, 11, 35 kV / custom |
| Frequency | 50 Hz or 60 Hz |
| Phase | 3-phase |
| Vector group | YNd11, YNd1 (custom) |
| Impedance | 9% – 13% (per spec) |
| Cooling method | ONAN / ONAF |
| Tap changer | On-load (OLTC) ±8×1.25% |
| Insulation level | LI325AC140 (66kV) |
| Temperature rise | 65K (oil); 65K (winding) |
| No-load loss | Per IEC 60076 / customer spec |
| Load loss | Per IEC 60076 / customer spec |
| Noise level | ≤65 dB (per IEC 60076-10) |
| Protection level | IP00 indoor; IP54 outdoor |
| Applicable standards | IEC 60076, IEEE C57.12.00 |
| Ambient temperature | -25°C to +40°C |
| Altitude | ≤1000m (derating above) |
| Accessories | OLTC, Buchholz, temp gauges, pressure relief, control cubicle |
Product Advantages
Verifiable benefits — not empty claims. Here’s exactly what you get when you choose HUACHEN.
Full Routine Test
IEC 60076-1 routine tests on every unit.
Fast Response
48h standard quote; 3–5 days custom.
English Docs
Complete documentation in English.
Witness FAT
Third-party witness testing available.
OEM Support
Custom branding and private label.
OLTC Standard
On-load tap changer included as standard.
Applications
Where this transformer is used — connecting the product to real-world industry applications.
Sub-transmission
66kV regional distribution substations.
Industrial
Factory main supply — 66/10kV step-down.
City Substation
Urban distribution — 66kV to 10kV.
Renewable
Solar/wind farm collection — 66kV.
Quality Proof — 9-Step Manufacturing Process
Every transformer passes through 9 quality-controlled stages, from raw material to shipping. Full traceability with documentation at every step.
Material Inspection
Raw material verification — core steel, copper, oil, accessories checked against certificates before production.
Core Cutting
CNC step-lap core cutting for low-loss grain-oriented silicon steel. Core loss measured before assembly.
Winding
Controlled winding tension, turn-count verification, and insulation paper application for each coil.
Assembly
Core-coil assembly with dimensional checks for fit, clearance, and clamping force.
Vacuum Drying
High-vacuum drying ovens remove moisture from insulation before oil impregnation.
Oil Filling
Filtered insulating oil with breakdown voltage >70kV/2.5mm and moisture <10ppm.
Final Testing
Full routine test per IEC 60076-1 — insulation, resistance, ratio, losses, withstand.
Packing
Sea-worthy export packing with shock-fixed crating for ocean shipping.
Shipping
On-time delivery with documentation — test reports, drawings, manuals in English.
Need a Custom Transformer Solution?
Our engineering team can assess non-standard voltage, capacity, impedance, or environmental conditions — and deliver a full proposal within 48 hours.