Product Overview & Design Compliance
The batch VKE20260310 consists of three-phase, cast-resin dry-type transformers with a rated capacity of 1000kVA, rated primary voltage of 10kV, and rated secondary voltage of 0.4kV. As a trusted China customized Epoxy Resin Dry Transformer factory, all units are engineered and tested in full accordance with:
- IEC 60076-11: Power transformers – Part 11: Dry-type transformers (International Electrotechnical Commission)
- GB/T 1094.11: Power transformers – Part 11: Dry-type transformers (National Standard of the People's Republic of China, harmonized with IEC 60076-11)
- IEC 60076-1: Power transformers – Part 1: General
- GB/T 1094.1: Power transformers – Part 1: General
These F Class Insulation Dry Type Power Transformer for sale feature a low-loss, high-permeability grain-oriented silicon steel core, high-strength epoxy resin cast windings, and a robust, fire-resistant enclosure, making them ideal for indoor installations, urban substations, and high-safety-requirement applications.
Factory Acceptance Test Results & Parameters
To guarantee product performance and reliability, VKE Transformer conducted a full suite of mandatory and type tests at our in-house testing center, with all results meeting or exceeding the requirements of IEC and GB standards. Key test parameters are as follows:
2.1 Winding Resistance Test
High-voltage (HV) winding resistance (per phase, at 20°C reference): ≤ 0.85 Ω (actual measured average: 0.82 Ω, deviation < 1%)
Low-voltage (LV) winding resistance (per phase, at 20°C reference): ≤ 0.0018 Ω (actual measured average: 0.0017 Ω, deviation < 1%)
All phase resistances are balanced, with inter-phase deviation well within the 2% limit specified by standards.
2.2 Voltage Ratio & Vector Group Test
Test Standard: IEC 60076-1 Clause 10.3, GB/T 1094.1 Clause 10.3
Test Purpose: Confirm the correct voltage transformation ratio and phase connection (vector group) to ensure compatibility with the power system.
Results:
Rated voltage ratio: 10000V / 400V
Actual measured ratio deviation: < ±0.5% (well within the ±0.5% tolerance for distribution transformers per IEC/GB standards)
Vector group: Dyn11 (standard for 10/0.4kV distribution transformers, verified 100% correct for all units)
2.3 No-Load Loss & No-Load Current Test
Test Standard: IEC 60076-1 Clause 10.4, GB/T 1094.1 Clause 10.4
Test Purpose: Measure core loss and excitation current, ensuring low energy consumption during operation.
Qualified Results:
No-load loss (P₀, at rated voltage and 20°C): ≤ 1.7 kW (actual measured average: 1.55 kW, 8.8% below standard limit)
No-load current (I₀, as % of rated current): ≤ 1.0% (actual measured average: 0.8%, 20% below standard limit)
2.4 Load Loss & Impedance Voltage Test
Test Standard: IEC 60076-1 Clause 10.5, GB/T 1094.1 Clause 10.5
Test Purpose: Verify winding loss and short-circuit impedance, ensuring compliance with system short-circuit requirements.
Qualified Results:
Load loss (Pₖ, at rated current and 75°C reference): ≤ 8.0 kW (actual measured average: 7.6 kW, 5% below standard limit)
Impedance voltage (Uₖ, at 75°C reference): 4.0% ± 10% (actual measured average: 3.98%, fully within tolerance)
2.5 Insulation Resistance Test
Test Standard: IEC 60076-11 Clause 12.2, GB/T 1094.11 Clause 12.2
Test Purpose: Check the insulation integrity of windings and core.
Qualified Results:
HV winding to ground / LV winding: ≥ 500 MΩ (actual measured average: > 1000 MΩ)
LV winding to ground / HV winding: ≥ 500 MΩ (actual measured average: > 1000 MΩ)
All values far exceed the minimum requirement of 100 MΩ specified in standards.
2.6 Induced Overvoltage Test (PD Test for Dry-Type Transformers)
Test Standard: IEC 60076-11 Clause 12.3, GB/T 1094.11 Clause 12.3
Test Purpose: Verify the dielectric strength of winding insulation and detect partial discharge (PD) activity.
Qualified Results:
Test voltage: 28kV (for 10kV class transformers, 2.8 × Uₘ, Uₘ=12kV)
Partial discharge level: ≤ 5 pC (actual measured average: < 3 pC, well below the 10 pC limit for distribution transformers)
No breakdown or flashover occurred during the test.
2.7 Lightning Impulse Voltage Test
Test Standard: IEC 60076-11 Clause 12.4, GB/T 1094.11 Clause 12.4
Test Purpose: Verify the ability of insulation to withstand lightning surge voltages.
Qualified Results:
HV winding lightning impulse test voltage (full wave, 1.2/50μs): 75kV
LV winding lightning impulse test voltage (full wave, 1.2/50μs): 8kV
All units passed the test without insulation breakdown or abnormal waveform distortion.
2.8 Temperature Rise Test
Test Standard: IEC 60076-11 Clause 12.5, GB/T 1094.11 Clause 12.5
Test Purpose: Verify the thermal performance of the transformer under rated load.
Qualified Results:
Winding temperature rise (by resistance method, F class insulation): ≤ 100K (actual measured average: 85K, 15% below limit)
Core and structural part temperature rise: ≤ 115K (actual measured average: 90K, fully compliant)
All units operate within safe temperature limits for continuous rated load.
2.9 Short-Circuit Withstand Test (Type Test)
Test Standard: IEC 60076-11 Clause 12.6, GB/T 1094.11 Clause 12.6
Test Purpose: Verify the mechanical strength of windings to withstand short-circuit currents.
Qualified Results:
All representative units passed the short-circuit withstand test, with no winding displacement, insulation damage, or electrical failure.
Post-test resistance, ratio, and impedance measurements confirmed no permanent damage.
VKE Transformer's Quality Commitment
At VKE Transformer, quality is the cornerstone of our business. Every transformer undergoes rigorous testing at every stage of production, from raw material inspection to final factory acceptance, to ensure compliance with the highest international standards. Our in-house testing center is equipped with advanced test equipment, and our engineering team follows strict quality control processes in line with ISO 9001:2015.
The successful completion of tests for batch VKE20260310 reaffirms our strength as a China customized Epoxy Resin Dry Transformer factory to supply high-performance F Class Insulation Dry Type Power Transformer for sale to global markets. These units are now ready for shipment, and we will provide full technical support, installation guidance, and after-sales service to our customers worldwide.
About VKE Transformer
VKE Transformer is a professional manufacturer of power transformers, specializing in dry-type transformers, oil-immersed transformers, and special transformers for industrial and renewable energy applications. With a focus on innovation, quality, and customer satisfaction, we serve customers in over 30 countries across Southeast Asia, Europe, the Middle East, and Africa, providing customized power solutions for a wide range of industries.