85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper
The 85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper is specially developed for 66–110 kV regional distribution networks and industrial users. It adopts 99.99 % electrolytic copper windings, high-permeability S13 grain-oriented silicon steel core, corrugated-fin tank + ONAN natural cooling, and ±5 % off-circuit tap changer (on-load optional). Fully compliant with IEC 60076, lightning impulse withstand 395 kV peak, PD <10 pC, noise ≤60 dB. Fully sealed conservator or sealed-type design with vacuum oil filling + nitrogen sealing guarantees >30-year maintenance-free operation even in high-altitude, high-pollution, or coastal areas. Ideal for mining, metallurgy, wind/solar grid connection, petrochemical plants, and urban 85 kV substations requiring maximum reliability and minimum losses.
- Primary Voltage Ratings 69kV 66kV 85kV or others
- Secondary Voltage Ratings 33/13.8/11 kV or customized
- H.V. Tap Range ±8×1.25% or others
- Type Oil-immersed power transformer
- BIL Up to 350kV
- Standards IEEE, ANSI, IEC, CSA
- Application regional substations, large mining & metallurgy plants, wind/solar grid connection
- Power Rating 1850kVA
- Certificate UL ,CESI ,ISO
- Cooling Method ONAN/ ONAF
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper
Technical Specifications
Accessories
| Rated Power | 1850kVA |
| Rating Primary Voltage | 69kV 66kV 85kV or others |
| Secondary Voltage |
33kV 13.8kV 11kV Customized |
| Frequency | 50/60Hz |
| Vector Group | Dyn11, YNd1, Dyn1, YNd11 or others |
| Winding Material | Aluminum/Copper |
| Efficiency | As IEEE, CAS Std or Customized |
| Impedance Voltage | As IEC |
| Altitude | ≤1,000m or Customized |
| Enclosure material | Mid Steel |
| HV Bushing |
| LV Bushing |
| OLTC/NLTC |
| Lifting hook for complete transformer |
| Name plate |
| Oil temperature |
| Winding temperature |
| Radiators |
| Oil level |
| Pressure relief valve |
| CT |
Customization Optional
85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper
The 85kV 1850kVA transformer offers virtually unlimited customization to perfectly match any 66–110 kV project requirement. Capacity can be scaled from 1000 kVA to 4000 kVA while retaining the same footprint. Clients may choose 100 % high-conductivity electrolytic pure copper windings for maximum efficiency and short-circuit withstand, or copper-aluminum hybrid windings for cost optimization. Core options include conventional S11/S13/S20 grain-oriented silicon steel or advanced amorphous metal cores achieving up to 75 % lower no-load losses. Primary voltage covers full 78 kV, 85 kV, 88 kV, and 90 kV classes with tap ranges of ±5 %, ±2×2.5 %, ±10 %, or non-standard. Secondary voltages include 11 kV, 13.8 kV, 10.5 kV, 6.3 kV, 0.69 kV, 0.4 kV, dual-voltage, or tertiary winding configurations for auxiliary supply or compensation. The vector group is fully selectable: Dyn11, YNd11, Yyn0, Dyn5, or special zigzag connections for harmonic mitigation and grounding requirements. Tap changer options range from simple off-circuit to high-speed vacuum on-load tap changers (±8×1.25 %, ±10×1 %, or ±12×1.5 %) with automatic voltage regulation (AVR), parallel operation logic, and remote SCADA control. Cooling systems include pure ONAN, multi-stage ONAF with redundant automatic fan groups, or ODAF forced-oil/forced-air for continuous 160 % overload capability. Tank designs comprise fully sealed corrugated fins for zero maintenance, a conservator with a rubber bladder or nitrogen cushion to eliminate oil-air contact, or modular detachable radiators with butterfly valves for easy transport and future expansion.
Advanced intelligent and environmental options transform the transformer into a future-proof smart asset. Integrated high-accuracy CT/PT compartments (metering 0.2s, protection 5P20/10P20) support revenue metering and differential protection. Real-time monitoring includes 8–16 channel fiber-optic direct hot-spot temperature sensors, online nine-gas dissolved gas analysis (DGA) with moisture and oxygen detection, bushing tanδ/capacitance monitoring, and UHF partial discharge sensors with cloud analytics. Protection suite features a fast-acting sudden pressure relay (<12 ms trip), a pressure relief device with an explosion vent, internal arc detection, and a rapid depressurization system. Enclosure options range from IP54/IP65 weatherproof housings with acoustic canopy (noise <55 dB) to complete walk-in substations. Special adaptations cover high-altitude operation above 5000 m with increased BIL and cooling, seismic qualification up to 0.6 g per IEEE 693, extreme temperature versions (-60 °C arctic with heater mats or +55 °C desert with enhanced ventilation), offshore/marine C5-M + CX epoxy coatings, and explosion-proof Ex design for Zone 2 hazardous areas. Full smart grid integration supports IEC 61850 GOOSE, DNP3, Modbus TCP/IP, and a built-in edge gateway for predictive maintenance, remote OLTC control, and digital twin compatibility. Every customization strictly complies with IEC 60076, GB/T 1094, and IEEE C57 standards, backed by comprehensive type, routine, and special test reports from KEMA, CESI, or STL laboratories, ensuring seamless commissioning and decades of reliable, future-ready performance in the most demanding 85 kV distribution networks worldwide.
Packing and Shipping
85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper
Immediately after FAT approval, the transformer is vacuum-dehydrated below 0.5 mbar for 72–96 hours, and hot oil is circulated until moisture ≤6 ppm and dielectric strength ≥75 kV/2.5 mm. The tank is then filled with 99.999 % ultra-dry nitrogen to 0.03–0.04 MPa positive pressure and hermetically sealed. A high-precision digital pressure & temperature data logger (180-day memory, 1-minute sampling) is permanently mounted on the conservator pipe for continuous monitoring throughout transit. All openings receive double blind flanges and tamper-evident seals. Nitrogen purity certificate, vacuum retention certificate, and real-time pressure trend report are included in the shipping dossier, ensuring zero insulation degradation even during extended ocean voyages.
All 85 kV porcelain bushings, neutral bushing, conservator, detachable radiator banks, OLTC drive mechanism, cooling fans, Buchholz relay, oil level gauges, temperature indicators, sudden pressure relay, and marshalling box are professionally dismantled. Each component is wrapped in VCI anti-corrosion film, placed in custom IPPC-fumigated marine-plywood crates with ≥60 mm high-density anti-shock foam, and packed with 300 kg color-indicating silica-gel desiccant. Four 3-axis shock recorders (±250 g) and two electronic tilt indicators are fixed to every crate. Crates are labeled in English/Chinese with part number, serial number, gross/net weight, and multilingual “Extremely Fragile – This Side Up” warnings.
The main tank (gross weight approx. 21–25 tons) is welded onto a DNV 2.7-1 certified heavy-lift steel saddle skid with 16 certified lashing points and four 120-ton lifting lugs. The entire body is enclosed in a fully sealed composite crate of 30 mm marine plywood reinforced with 120×120 mm galvanized steel beams, then triple-wrapped with aluminum-foil vapor barrier and heavy-duty heat-sealed tarpaulin. Ten high-resolution digital impact recorders (trigger >3 g) and real-time GPS/4G tilt & vibration monitors are permanently attached. External surfaces are painted bright yellow with permanent stenciling: “85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper – Gross Weight 25 Tons – Do Not Roll – Keep Dry – Use Spreader Beam Only”.
Inland transport uses hydraulic modular or low-bed trailers (total height ≤4.5 m). Sea freight is break-bulk under-deck or on 40 ft heavy-duty flat-rack containers with CCS/DNV-GL approved lashing using Φ30 mm steel wire ropes and 100-ton turnbuckles. Complete documentation includes a detailed packing list, IPPC fumigation certificate, certificate of origin (Form A/E), nitrogen pressure & trend report, shock recorder baseline data, 110 % all-risk marine insurance, third-party loading survey report, and full installation manual. These rigorous procedures guarantee every unit arrives worldwide in perfect, ready-to-energize condition with zero damage and full traceability.
All 85 kV porcelain bushings, neutral bushing, conservator, detachable radiator banks, OLTC drive mechanism, cooling fans, Buchholz relay, oil level gauges, temperature indicators, sudden pressure relay, and marshalling box are professionally dismantled. Each component is wrapped in VCI anti-corrosion film, placed in custom IPPC-fumigated marine-plywood crates with ≥60 mm high-density anti-shock foam, and packed with 300 kg color-indicating silica-gel desiccant. Four 3-axis shock recorders (±250 g) and two electronic tilt indicators are fixed to every crate. Crates are labeled in English/Chinese with part number, serial number, gross/net weight, and multilingual “Extremely Fragile – This Side Up” warnings.
The main tank (gross weight approx. 21–25 tons) is welded onto a DNV 2.7-1 certified heavy-lift steel saddle skid with 16 certified lashing points and four 120-ton lifting lugs. The entire body is enclosed in a fully sealed composite crate of 30 mm marine plywood reinforced with 120×120 mm galvanized steel beams, then triple-wrapped with aluminum-foil vapor barrier and heavy-duty heat-sealed tarpaulin. Ten high-resolution digital impact recorders (trigger >3 g) and real-time GPS/4G tilt & vibration monitors are permanently attached. External surfaces are painted bright yellow with permanent stenciling: “85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper – Gross Weight 25 Tons – Do Not Roll – Keep Dry – Use Spreader Beam Only”.
Inland transport uses hydraulic modular or low-bed trailers (total height ≤4.5 m). Sea freight is break-bulk under-deck or on 40 ft heavy-duty flat-rack containers with CCS/DNV-GL approved lashing using Φ30 mm steel wire ropes and 100-ton turnbuckles. Complete documentation includes a detailed packing list, IPPC fumigation certificate, certificate of origin (Form A/E), nitrogen pressure & trend report, shock recorder baseline data, 110 % all-risk marine insurance, third-party loading survey report, and full installation manual. These rigorous procedures guarantee every unit arrives worldwide in perfect, ready-to-energize condition with zero damage and full traceability.
32
32 years of industry experience
Manufacturer Test
85kV 1850kVA Outdoor Oil Immersed Distribution Transformer Copper
Progress test
Staged tests with full client-witness option:
- Core-coil stage: winding DC resistance at all taps, insulation resistance & PI ≥ 2.6, core grounding current <80 mA, preliminary no-load loss measurement.
- Pre-tanking: voltage ratio at principal and extreme taps (deviation ≤ ±0.5 %), vector group (Dyn11/YNd11) verification, polarity and magnetic balance test.
- After vapor-phase drying & vacuum oil filling: final insulation resistance >18,000 MΩ, tanδ ≤ 0.0038 (20 °C), partial discharge <10 pC at 1.5Um/√3, oil BDV ≥ 75 kV/2.5 mm, moisture <8 ppm.
- Final sealing: 48-hour static leakage test, 0.45 bar positive/negative pressure test for 24 h each, OLTC contact resistance and mechanical operation if applicable.
All results are fully documented and submitted for client/third-party approval before FAT.
Design Tests
All transformers will be tested after finishing the production test items as below:
♦ Leak testing with pressure for liquid-immersed transformers
♦ Test of transformer oil
♦ Measurement of voltage ratio and check of phase displacement
♦ Measurement of winding DC resistance
♦ Measurement of d. c. Insulation resistance between each winding to earth, and check of the core and frame insulation
♦ Capacitive bushing test
♦ Measurement of dissipation factor (tan δ) of the insulation system capacitances, and determination of capacitances windings-to-earth
♦ Measurement of no-load loss and current at 90%,100%,110% of rated voltage
♦ Operation test on on-load tap-changer
♦ Measurement of short-circuit impedance and load loss
♦ Lightning impulse test
♦ Induced-voltage test with partial discharge measurement
♦ Auxiliary wiring check
♦ Current transformer test
♦ Frequency response analysis test
Transformer Factory Acceptance Test
The 85kV 1850kVA transformer undergoes complete FAT strictly per IEC 60076 with client/third-party witness and signed protocol. Tests include winding resistance at all taps (corrected to 75 °C), voltage ratio & polarity at principal/extreme taps (≤ ±0.5 %), vector group verification, no-load loss/current at 90–110 % voltage, load loss & impedance at rated current, separate-source and induced withstand voltage with PD <10 pC at 1.5Um/√3, full-wave lightning impulse 395 kV peak, insulation resistance/PI (≥ 2.6)/tanδ/oil BDV ≥ 75 kV, tap-changer 10 full cycles + 50 auxiliary cycles, functional test of cooling system, Buchholz relay, sudden pressure relay and temperature indicators, sound level ≤ 60 dB, and final visual, painting, nameplate and nitrogen pressure inspection. Full raw data and calibration certificates are provided; the transformer is released only after client's signature, ensuring 100 % readiness for immediate energization.
Routine Test - Test of transformer oil
Purpose of Testing
The purpose of testing transformer oil is to evaluate its condition and ensure it is still effective in providing insulation and cooling for the transformer. This test helps detect contaminants such as moisture, gas buildup, or impurities, which can compromise the oil’s performance and, consequently, the transformer’s reliability and longevity. Regular oil testing enables early detection of potential issues, allowing for corrective actions to prevent transformer failure.
Testing Equipment
Dielectric Strength Tester: Measures the insulating capacity of the oil by applying high voltage.
Dissolved Gas Analyzer (DGA): Detects gases in the oil that indicate internal faults.
Acid Value Tester: Determines the oil's acidity to check for oxidation.
Dissolved Gas Analyzer (DGA): Detects gases in the oil that indicate internal faults.
Acid Value Tester: Determines the oil's acidity to check for oxidation.
Pre-Test Preparation
Disconnect the transformer from the electrical grid to avoid any electrical hazards during testing.
Prepare oil sampling kits, testing instruments (e.g., dielectric strength tester, gas analyzer), and clean containers for oil samples.
Ensure all personnel are equipped with necessary safety gear, such as gloves, goggles, and protective clothing.
Visually inspect the oil for signs of contamination or abnormal color before collecting samples.
Prepare oil sampling kits, testing instruments (e.g., dielectric strength tester, gas analyzer), and clean containers for oil samples.
Ensure all personnel are equipped with necessary safety gear, such as gloves, goggles, and protective clothing.
Visually inspect the oil for signs of contamination or abnormal color before collecting samples.
Test Progress
Oil Sampling:
Carefully extract oil samples from the transformer at specific locations (such as the oil conservator or top of the tank) to ensure accurate representation of the oil’s condition.
Chemical and Gas Analysis:
The pressure is maintained for a set period (usually 30-60 minutes) to observe if there is any drop in pressure, which could indicate a leak.
Carefully extract oil samples from the transformer at specific locations (such as the oil conservator or top of the tank) to ensure accurate representation of the oil’s condition.
Chemical and Gas Analysis:
The pressure is maintained for a set period (usually 30-60 minutes) to observe if there is any drop in pressure, which could indicate a leak.
Test Standard
IEC 60076 Oil-immersed power transformers
ASTM D1816 Dielectric Breakdown Voltage of Insulating Liquids
ASTM D1816 Dielectric Breakdown Voltage of Insulating Liquids
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
85 kV regional substations, large mining & metallurgy plants, wind/solar grid connection, petrochemical & refining facilities, railway traction substations, urban high-voltage distribution networks.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
Transformers Packaging (1)
Transformers Packaging (2)
Transformers Packaging (3)
Transformers Packaging (4)
Transformers Packaging (5)
Transformers Packaging (6)
Transformers Packaging (7)
Transformers Packaging (8)
Related Products
15kVA Completely self-protected(CSP) Single Phase Pole Mounted Transformer
NPC ELECTRIC the production of 15 kVA Completely Self-Protected (CSP) single-phase overhead transformers, meticulously engineered to meet international standards such as IEEE C57.12.00, IEEE C57.12.20, DOE-2016 Efficiency, CSA C2.1, and CSA C2.2. These certifications underscore to delivery products that are both safe and reliable. NPC electric transformers are designed to comply with the DOE 2016 efficiency standards, ensuring optimal energy efficiency and reduced operational costs. Understanding the diverse needs of our clients, NPC Electric offers a wide range of customizable voltage levels to suit various applications. Perfect manufacturing processes enable us to maintain short production cycles, ensuring timely delivery.
220kV 230kV Power Transformer
NPC ELECTRIC's 220kV and 230kV power transformer complies with the International Electrotechnical Commission (IEC) standards as below: 1. IEC 60076 Power Transformers; 2. AS NZS 60076 Power Transformers CSAC88-16 Power Transformers; 3. ANSI/IEEE C57.12.00 IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers; 4. GOST R 52719 Power Transformers - General Specifications; 5. EN60076 Poer Transformer; 6. Local After-Sales Services In North America South
400kVA Dry Type Transformer
The NPC ELECTRIC 400kVA Dry Type Transformer is engineered for efficient and reliable power distribution in industrial, commercial, and utility applications. With a compact, fire-safe design, it operates without the need for oil or other cooling fluids, making it ideal for environments with strict safety and environmental standards. Designed to withstand heavy loads, it is the perfect solution for demanding electrical requirements, providing a sustainable and cost-effective option for modern electrical systems.
45kVA Three Phase Pad Mounted Transformer
The 45 kVA pad-mounted transformer meets ANSI, CSA, NEMA, IEEE, and DOE standards. NPC Electric's 45 kVA pad-mounted transformers comply with DOE efficiency values and are UL listed. Based on specific technical requirements, the iron core can be designed as either a three-legged or five-legged assembly structure.
167kVA Conventional Type Single Phase Pole Mounted Transformer
NPC ELECTRIC'S 167kVA Conventional Type Single Phase pole Mounted transformer is a high capacity single phase distribution transformer designed for medium to high load distribution systems. It is mainly used in residential, commercial, agricultural and light industrial applications to provide stable single phase power to ensure reliable operation of user-side equipment. It complies with international standards such as ANSI/IEEE C57, IEC60076 and other standards to ensure its high quality and stability.
250kVA Single Phase Pad Mounted Transformer
NPC ELECTRIC 250 kVA single phase pad mounted transformer operates safely, reliably, and efficiently and can be installed indoors and outdoors. The industrial transformer has a rated power of 250 kVA, a primary voltage of 27600/16000V single-phase and a secondary voltage of 120/240V single-phase.The transformer has a primary loop feed and dead front primary connections.FAQ From Customers
-
What is a Transformer?A transformer is an electrical device used to change the voltage of alternating current (AC). It works on the principle of electromagnetic induction, converting high-voltage current into low-voltage current or low-voltage current into high-voltage current. Transformers are widely used in power transmission, distribution systems, and various electronic devices.
-
What are the main uses of a transformer?The main use of a transformer is voltage conversion. Transformers are used in power transmission systems to help transfer electricity from power plants to consumers. In addition, transformers are also used in electronic devices such as chargers, televisions, power adapters, etc., to adjust the voltage to meet the requirements of different devices.
-
Do you have UL listed?Yes, our transformer has UL listed. We have exported to America many pad mounted transformer,substation transformer and HV.
Welcome your inquiry
Honesty, Integrity, Frugality, Activeness and Passion