33/11kV oil immersed transformers
33/11kV oil immersed transformers
Designed for regional substations, 33/11kV oil immersed transformers step down high-voltage power to 11kV for safe and efficient distribution. Ideal for urban grids, industrial zones, and utility networks, these transformers ensure stable performance and long service life under demanding load conditions.
What Are 33/11kV Oil Immersed Transformers?
33/11kV oil immersed transformers are three-phase power distribution transformers designed to step down high voltage (33kV) to medium voltage (11kV) in regional substations or large-scale infrastructure. These transformers use mineral or biodegradable insulating oil for both cooling and electrical insulation, ensuring safe and reliable power delivery even under heavy load conditions.
They play a key role in medium-voltage distribution systems, especially in utility grids, industrial zones, and municipal power networks.
Why Use 33/11kV Oil Immersed Transformers?
High Efficiency:
Equipped with low-loss silicon steel cores and precision-wound copper or aluminum coils, these transformers achieve excellent energy efficiency. Loss levels meet or exceed international low-loss standards, such as IEC 60076 and DOE 2016.
Long Service Life:
Robust mechanical design with hermetically sealed steel tanks, high-grade insulation, and corrosion protection ensures over 25 years of reliable operation in both indoor and outdoor installations.
Voltage Adaptability:
Supports multiple voltage series including:
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11kV Series
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15kV up to 36kV Series
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33kV Series
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35kV Series
You can easily navigate technical datasheets for each voltage range.
Key Features of 33/11kV Oil Immersed Transformers
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Core and Windings:
High-permeability cold-rolled silicon steel core + high-conductivity copper or aluminum windings for reduced load and no-load losses. -
Cooling System:
Standard ONAN (Oil Natural Air Natural) cooling, with optional ONAF for high-capacity models. External radiators or corrugated tanks provide effective heat dissipation. -
Protection & Safety Devices:
Includes Buchholz relay, pressure relief valve, oil level gauge, temperature sensor, and optional surge arresters or on-load tap changers (OLTC) for stable voltage regulation. -
Low Noise and Vibration:
Typically <55–60 dB(A) for 1000kVA, suitable for installation near residential or urban zones. -
Environmental Options:
Available with biodegradable oils and sealed tank design to prevent leakage and minimize ecological impact.
Applications of 33/11kV Oil Immersed Transformers
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Utility Substations
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Industrial and Mining Projects
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Commercial Complexes and Data Centers
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Renewable Energy Plants (Solar, Wind)
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Municipal Infrastructure Projects
Standards and Compliance
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Design Standards:
IEC 60076, ANSI/IEEE C57.12, GB, AS, CSA -
Testing:
100% routine tests per IEC/IEEE standards; optional type and special tests available on request -
Certifications:
CE, ISO9001, ISO14001, ISO45001, RoHS (on request)
Advantages of CHBEB 33/11kV Oil Immersed Transformers
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Stable, Low-Loss Performance
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High Thermal and Short-Circuit Strength
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Adaptable to Harsh or Humid Environments
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Factory Customization Available (Impedance, Tappings, Tank Type)
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Cost-Effective Solution for Long-Term Distribution Projects
Choose CHBEB
Choose CHBEB 33/11kV oil immersed transformers for a safe, efficient, and long-lasting distribution solution. Backed by 60+ years of manufacturing experience, CHBEB delivers customized transformer solutions for projects across Asia, the Middle East, Africa, and beyond.
👉 Need detailed specs?
Browse our product tables under:
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11kV Series
Capacity (kVA) Voltage Combination Vector group No-load loss (W) Load loss (W) (75°C) Impedance voltage (%) No-load current (%) HV Tapping range of HV LV 25 6 kV 6.6Kv 10.5kV 11kV ±5%,±2×2.5% 0.38 kV 0.4 kV 0.415 kV 0.48 kV Yyn0 Dyn5 Dyn11 100 600 4.0 1.7 50 130 870 1.6 63 150 1040 1.5 80 180 1250 1.4 100 200 1500 1.3 125 240 1800 1.2 160 280 2200 1.1 200 340 2600 1 250 400 3050 0.9 315 480 3650 0.9 400 570 4300 0.8 500 680 5100 0.8 630 810 6200 4.5 0.7 800 980 7500 0.6 1000 1160 10300 0.55 1250 1360 12000 0.5 1600 1640 14500 0.45 2000 1940 18500 5.5 0.4 2500 2300 20500 0.4 -
15kV up to 36kV Series
Capacity (kVA) Voltage Combination Vector group No-load loss (W) Load loss (W) (75°C) Impedance voltage (%) No-load current (%) HV Tapping range of HV LV 630 13.2kV 13.8kV 15 kV 20 kV 22 kV 33 kV 34.5 kV ±5%,±2×2.5% 0.38 kV 0.4 kV 0.415 kV 0.48 kV Yd11 1150 6200 4.5 0.9 800 1400 7500 5.5 0.8 1000 1650 10300 0.7 1250 1950 12800 0.6 1600 2300 14500 0.6 2000 2650 17100 0.6 2500 3100 20000 0.6 3150 3650 23700 0.5 4000 4450 28100 0.5 5000 5200 32700 0.5 6300 6150 36900 0.5 8000 8900 44000 0.4 10000 11600 50600 6.5 0.4 -
33kV Series
Capacity (kVA)VoltageVector groupNo-load loss (W)Load loss (W)(75°C)Impedance voltage (%)No-load current (%)PrimaryTapping range (%)Secondary5033 kV±5%0.38 kV0.4 kV0.415 kV0.48 kVYyn06.512106.52.010030520201.8012534023801.7516036028301.6520043033001.5525051039501.4031561047501.4040073557501.3050087069001.30630104082501.25800125099001.0510001480121501.0012501760146000.9016002130175000.8520002500206800.7525002975245000.75 -
35kV Series
Capacity (kVA) Voltage Vector group No-load loss (W) Load loss (W) (75°C) Impedance voltage (%) No-load current (%) Primary Tapping range (%) Secondary 50 33 kV ±5% 0.38 kV 0.4 kV 0.415 kV 0.48 kV Yyn0 6.5 1210 6.5 2.0 100 305 2020 1.80 125 340 2380 1.75 160 360 2830 1.65 200 430 3300 1.55 250 510 3950 1.40 315 610 4750 1.40 400 735 5750 1.30 500 870 6900 1.30 630 1040 8250 1.25 800 1250 9900 1.05 1000 1480 12150 1.00 1250 1760 14600 0.90 1600 2130 17500 0.85 2000 2500 20680 0.75 2500 2975 24500 0.75
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CHINA BEI ER BIAN (CHBEB) GROUP, with 218 million in registered capital, originated from Beijing Beierbian Transformer Group. Headquartered in Beijing for R&D, it operates major production bases in Nanjing and Yueqing, producing high-quality products.
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- chbebgroup@chbebpower.com
- +86 15558785111
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JiangSu
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WenZhou
No.211, Wei 16 Road, Industrial Zone, Yueqing, Wenzhou, Zhejiang, China.
XiangYang Industrial Zone ,YueQing,WenZhou,ZheJiang,China