Oil-Immersed Transformers · Distribution
50 kVA 33kV Three-Phase Oil-Immersed Distribution Transformer
This 50 kVA oil-immersed distribution transformer is designed for reliable power...
Voltage Class — 33 kV Medium Voltage Distribution
33kV Distribution & Power Transformers
33 kV (33,000V nominal, Um = 36kV, 170kV BIL) is the dominant sub-transmission and primary distribution backbone for Sub-Saharan Africa, the Middle East, South America, and Commonwealth grids. XinHuan manufactures high-reliability IEC 60076 oil-immersed distribution transformers (50 kVA to 5000 kVA) and primary substation transformers (up to 31.5 MVA) with factory-direct pricing, certified routine FAT reports, and rapid ocean shipping to Lagos, Mombasa, Tema, Durban, and Middle East ports.
50–10,000
kVA range
33 kV / 0.415 kV
primary ratio
170 kV BIL
impulse withstand
24h
quote response
Product Range
33kV Distribution & Power Transformers — 64 Models Available
Standard and custom capacities available for global utility, industrial, and commercial projects. View complete catalog →
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Technical Overview
33kV to 415V / 400V / 11kV — Grid Extension & Industrial Power
33 kV primary distribution lines enable long-distance rural electrification and heavy industrial power transmission with significantly lower I²R feeder line losses compared to 11kV networks. In Nigeria (NEMSA/DisCos), Kenya (KPLC/REREC), Ghana (ECG/VRA), Zambia (ZESCO), South Africa (Eskom), and Saudi Arabia (SEC), 33kV transformers step down directly to 415V/240V for industrial estates or 11kV for municipal distribution injection substations.
XinHuan manufactures both hermetically sealed corrugated-tank units (up to 2500 kVA) and conservator-type transformers equipped with double-float Buchholz relays, magnetic oil level gauges, dehydrating silica gel breathers, and dial thermometers. High-permeability grain-oriented CRGO silicon steel step-lap cores deliver ultra-low no-load idle losses compliant with IEC Tier 2 and local utility efficiency mandates.
Every 33kV transformer is subjected to 100% routine Factory Acceptance Testing (FAT) in our Hefei high-voltage laboratory: DC winding resistance, ratio and Dyn11/YNd11 vector check, short-circuit impedance and load loss (Pk), 70 kV 1-minute power-frequency separate-source withstand, and induced overvoltage test. Third-party inspection (SGS, Bureau Veritas, Intertek) is warmly welcomed.
33kV Distribution & Power Transformers — Key Specifications
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Rated High Voltage (HV)
33 kV (30 kV / 33 kV / 34.5 kV / 35 kV nominal options, Um = 36 kV)
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Rated Low Voltage (LV)
0.415 kV (415V/240V), 0.400 kV (400V/230V), 11 kV, or 6.6 kV
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Lightning Impulse Withstand (BIL)
170 kV peak lightning impulse / 70 kV power frequency withstand (IEC 60076-3)
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Capacity Range
50 kVA – 5000 kVA distribution; up to 31.5 MVA sub-transmission
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Cooling Method
ONAN (Oil Natural Air Natural) standard; ONAF dual-speed fans available
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Vector Group & Taps
Dyn11 (standard distribution) or YNd11 / YNyn0; ±2×2.5% or ±4×2.5% OCTC (OLTC available)
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Bushings & Creepage
Outdoor porcelain or silicone rubber bushings with >= 900mm heavy-pollution creepage
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Applicable Standards
IEC 60076-1, IEC 60076-2, IEC 60076-3, GB/T 1094, SANS 780, BS 171
IEC / IEEE Reference Data
33kV Distribution & Power Transformers — Standard Capacity & Loss Parameters
| Rated Capacity | Voltage Ratio (HV / LV) | No-Load Loss (P0) | Load Loss (Pk) | Impedance (Uk%) | No-Load Current (I0%) | Approx. Total Weight |
|---|---|---|---|---|---|---|
| 100 kVA | 33 / 0.415 kV | 230 W | 1,800 W | 4.5% | 1.2% | 820 kg |
| 200 kVA | 33 / 0.415 kV | 380 W | 2,950 W | 4.5% | 1.0% | 1,180 kg |
| 315 kVA | 33 / 0.415 kV | 520 W | 4,100 W | 4.5% | 0.9% | 1,540 kg |
| 500 kVA | 33 / 0.415 kV | 740 W | 5,800 W | 5.0% | 0.8% | 2,150 kg |
| 630 kVA | 33 / 0.415 kV | 890 W | 6,900 W | 5.0% | 0.7% | 2,580 kg |
| 800 kVA | 33 / 0.415 kV | 1,060 W | 8,200 W | 5.5% | 0.7% | 3,050 kg |
| 1000 kVA | 33 / 0.415 kV | 1,250 W | 9,800 W | 5.5% | 0.6% | 3,650 kg |
| 1250 kVA | 33 / 0.415 kV | 1,480 W | 11,800 W | 6.0% | 0.6% | 4,380 kg |
| 1600 kVA | 33 / 0.415 kV | 1,780 W | 14,500 W | 6.25% | 0.5% | 5,250 kg |
| 2000 kVA | 33 / 0.415 kV | 2,150 W | 17,500 W | 6.5% | 0.5% | 6,400 kg |
| 2500 kVA | 33 / 0.415 kV | 2,550 W | 21,000 W | 6.5% | 0.4% | 7,600 kg |
| 3150 kVA | 33 / 0.415 kV | 3,100 W | 25,500 W | 7.0% | 0.4% | 9,100 kg |
| 5000 kVA | 33 / 11 kV | 4,400 W | 35,000 W | 7.5% | 0.3% | 13,500 kg |
Guaranteed parameters based on standard factory testing. Custom loss levels (Tier-2 Ecodesign, DOE 2016, and high-efficiency low-noise designs) are engineered on request.
33kV Distribution & Power Transformers — 3D Engineering Anatomy Cutaway
High-precision 3D component breakdown of 33kV Distribution & Power Transformers illustrating CRGO silicon steel core assembly, electrolytic copper windings, insulation, and protection accessories.
High-Grade Silicon Core
Electrolytic Copper Coil
Off-Circuit / OLTC Tap Switch
Buchholz & Temp Relays
33kV Distribution & Power Transformers — Factory Acceptance Testing (FAT)
Watch routine factory testing and quality control inspections inside XinHuan's manufacturing facility.
100% full routine tests (IEC 60076) conducted before export packing.
Engineering Submittal & Layout Workbench
Substation Room Fit & Multi-Equipment CAD Footprints
Select your equipment type and capacity to inspect verified GA engineering CAD line drawings, Single Line Diagrams (SLD), dimensions (L × W × H), roller gauge, and submittal clearances before procurement.
Available Ratings:
11kV / 33kV Dual Voltage
IEC 60076 / IEEE Compliant
100% Routine Factory Tested
Export Nitrogen / Seaworthy Pack
1000 kVA Technical Dimensions
IEC 60076-1International utility & industrial submittal specifications
| Overall Length (L) | 1,750 mm |
|---|---|
| Overall Width (W) | 1,120 mm |
| Overall Height (H) | 1,780 mm |
| Roller Wheel Track Gauge (D) | 820 mm |
| Total Equipment Net Weight | 3,820 kg |
| Min Substation Clearance | 1,000 mm surrounding |
| Rated Voltage / System | 11 kV / 33 kV Dual Primary |
| Applicable Standard | IEC 60076-1 / IEEE C57 |
Download Technical Data Sheet (PDF)
Request Factory Engineering Submittal Package
Full CAD DXF/DWG vector footprints, 3D STEP models, and custom project submittals provided within 2 hours upon request.
Factory Facility & Verification
Real Completed Transformers & Factory Workshop
Direct visual proof of XinHuan's manufacturing capability in Hefei, China. Unedited photographs showing our finished distribution transformer workshop, marked finished products area, cast resin dry-type stock, and export container loading.
Finished Transformer Workshop
Real completed units staged in orderly rows, ready for final project inspection, FAT witnessing, and international dispatch.
Dry-Type Transformer Bay
F/H-class cast resin coils and harmonic mitigation dry-type distribution transformers in stock.
Finished Products Area
Clear production-stage segregation and routine quality verification for procurement teams prior to container packaging.
Active Assembly Floor
Precision silicon steel core stacking, copper coil winding assembly, and tank fabrication.
Vacuum Autoclave Drying
Heavy-duty vacuum autoclave drying process ensuring zero residual moisture in coil insulation.
Export Preparation & Shipping
Direct container packing and heavy-duty ocean freight loading outside our Hefei facility.
Quality & Compliance
Certified B2B Manufacturing & Laboratory Performance
Every transformer, compact substation, and switchgear unit is engineered under audited ISO quality management systems and type-tested according to IEC 60076 and ANSI C57 international standards.
IAF / CNAS Accredited
ISO 9001:2015 Quality System
Certified Quality Management System covering design, coil winding, vacuum drying, oil filling, and routine testing of 10kV–35kV distribution transformers.
Environmental System
ISO 14001:2015 Environmental
Environmental Management System certifying low-loss eco-designed core assemblies, zero PCB insulation oil, and environmentally safe production controls.
Occupational Health
ISO 45001:2018 Safety System
Occupational Health and Safety Management System ensuring safety containment in high-voltage testing bays and factory assembly protocols.
CNAS Lab Type Tests
IEC 60076 & GB Type Tests
Complete routine and type test records (temperature rise, impulse voltage withstand, short-circuit withstand) conducted at CNAS-accredited national research institutes.
SGS Audited Supplier
SGS Verified Manufacturer Audit
On-site factory audit certificate by SGS / Made-in-China, verifying manufacturing premises, export capacity, assembly lines, and legal qualification.
≥180 Units/Yr Export
International Delivery Certificate
Verified annual supply performance and delivery certificate for overseas power grid EPC and industrial infrastructure projects (Mozambique, Nigeria, Kenya, SEA).
Technical Q&A
Frequently Asked Questions — 33kV Distribution & Power Transformers
Per IEC 60076-3, the highest equipment voltage Um is 36 kV. The standard Lightning Impulse Withstand Voltage (BIL) is 170 kV peak (or 200 kV peak upon utility specification), and the separate-source power-frequency AC withstand voltage is 70 kV RMS for 1 minute.
Yes. We supply 33kV/0.415kV (or 33kV/400V) step-down transformers for direct low-voltage distribution to industrial factories, mines, and estates. We also build 33kV/11kV and 33kV/6.6kV inter-tie transformers for primary utility distribution substations and solar step-up facilities.
For high-ambient regions such as the Middle East, North Africa, and the Sahel where ambient temperatures reach 50°C, our transformers are engineered with lower temperature rise limits (50K top oil / 55K winding), C5-M marine epoxy anti-corrosion coating, UV-resistant porcelain or composite bushings with >= 900mm creepage distance, and optional automatic dual-speed ONAF cooling radiators.
Standard accessories include a double-float Buchholz gas/oil surge relay with alarm and trip contacts, dial-type oil thermometer with microswitches, magnetic liquid level gauge, spring-loaded pressure relief device (PRD) with directional deflector, silica gel dehydrating breather, and off-circuit tap changer (±2×2.5% or ±4×2.5%).
Yes. For regional grid substations, industrial parks, and solar PV plants requiring automated voltage regulation under load, we equip 33kV units with vacuum or oil-type OLTC (typically ±8×1.25% or ±10×1.5% tap range) complete with remote Automatic Voltage Regulator (AVR) control cabinets.
Dyn11 pairs a Delta (D) 33kV primary with a Star (yn) 415V secondary. The delta primary isolates third-harmonic zero-sequence currents within the closed loop, preventing harmonic distortion on upstream lines. The star secondary with grounded neutral provides a robust 4-wire supply (415V phase-to-phase, 240V phase-to-neutral) that safely handles 100% unbalanced single-phase loads.
Every transformer undergoes 100% routine tests in our Hefei high-voltage test bay per IEC 60076-1: DC winding resistance, ratio and vector group check, short-circuit impedance and load loss (Pk), no-load loss and excitation current (Po/Io), 70kV separate-source AC dielectric withstand, and induced overvoltage test. Routine test certificates accompany each shipment.
Please specify: rated capacity (kVA or MVA), primary voltage (33kV) and secondary voltage (e.g., 415V or 11kV), vector group (Dyn11/YNd11), cooling method (ONAN/ONAF), conductor material (copper or aluminum), quantity, and destination port (Lagos, Mombasa, Tema, Durban, Dammam, etc.) to receive an authoritative CIF or FOB quote within 24 hours.
Export Markets
Where 33kV Distribution & Power Transformers Are Supplied
Engineering Reference Silo
Transformer Category Pillars & International Standards
Engineering Link Magnets & CAD Resources:
33kV Distribution & Power Transformers — Direct Factory Quotation
Request Engineering Submittals & Price
Include capacity (kVA), capacity (kVA), primary (33kV), secondary (415V or 11kV), cooling (ONAN/ONAF), destination port, and required quantity. Our engineers respond with certified data sheets within 24 hours.