1250kva 10kv 400v Oil Immersed Transformer Electrical Transformers

1250kva 10kv 400v Oil Immersed Transformer Electrical Transformers

1. Product Overview

The 1250kva 10kv 400v Oil Immersed Transformer Electrical Transformers are high-capacity three-phase distribution transformers engineered for heavy-load municipal power grids, large industrial parks and commercial complex power distribution systems. Manufactured in full compliance with IEC 60076 international power transformer standards and GB/T 6451 industry specifications, this 10kV to 400V step down oil immersed transformer serves as core power conversion equipment for heavy-duty power supply scenarios, delivering stable voltage regulation, low operational loss and reliable continuous load performance.

Featuring a standard 10kV high-voltage input and 400V low-voltage output configuration, this industrial oil immersed electrical transformer efficiently steps down medium-voltage grid power into usable three-phase low-voltage electricity for large-scale manufacturing production, commercial building operation and urban regional centralized power supply. Adopting mature fully sealed oil immersion cooling technology and high-grade anti-aging mineral insulating oil, the 1250kVA oil immersed distribution transformer offers superior heat dissipation efficiency, strong short-term overload resistance and excellent outdoor environmental adaptability. Unlike conventional dry-type electrical transformers, this oil type power transformer supports long-term full-load outdoor operation with lower lifecycle maintenance costs and higher operational stability.

Every finished 1250kva 10kv 400v oil immersed transformer undergoes rigorous factory testing including partial discharge detection, temperature rise testing, short-circuit impact verification and full-load aging inspection. Built with upgraded energy-saving electromagnetic structure and premium winding materials, this heavy-duty oil immersed power transformer has become a mainstream choice for urban grid expansion, large industrial power matching and comprehensive infrastructure power supply projects across global markets.

2. Technical Parameters

3. Core Product Features

This 1250kva 10kv 400v oil immersed electrical transformer adopts upgraded low-loss electromagnetic design and fully sealed heavy-duty structure, solving high energy consumption, poor stability and insufficient load capacity issues of traditional large-capacity transformers. It delivers reliable and efficient performance for long-term full-load and frequent overload operation in heavy industrial and municipal power distribution systems:

3.1 Ultra-low Loss & High Energy-saving Performance

The transformer core adopts high-permeability grain-oriented cold-rolled silicon steel sheets with full oblique lap joint technology, which effectively suppresses magnetic flux leakage and minimizes no-load iron loss during standby and continuous operation. The precisely wound pure copper coils feature low internal resistivity and uniform winding density, greatly reducing load loss under heavy full-load operation. As an energy-saving oil immersed distribution transformer, it significantly cuts down daily power consumption and grid line loss, bringing substantial long-term energy-saving benefits for large industrial parks and urban regional power grids.

3.2 Mature Oil Immersed Cooling & Sealed Insulation System

Filled with environmental-friendly non-PCB anti-aging mineral insulating oil compliant with IEC standards, the 1250kVA step-down transformer adopts standard ONAN natural circulation cooling mode. The autonomous oil circulation system continuously absorbs and dissipates heat generated by heavy-load power conversion, ensuring stable internal temperature during 24-hour uninterrupted full-load operation. The fully sealed corrugated oil tank structure isolates internal insulating oil from external air, moisture and dust, preventing oil emulsification, oxidation and insulation aging, and maintaining excellent dielectric performance in harsh outdoor and high-load industrial environments.

3.3 Stable Voltage Output & Strong Anti-interference Capability

Equipped with high-precision off-load voltage tapping adjustment function within ±5% range, this three-phase electrical transformer accurately calibrates 10kV input voltage deviation caused by long-distance transmission loss and peak load fluctuation, ensuring constant standard 400V low-voltage output. Optional Dyn11 and Yyn0 vector group designs evenly balance three-phase current, effectively suppress grid harmonic interference and instantaneous voltage surge, and adapt to dynamic heavy-load changes of large industrial machinery and municipal centralized power loads. It effectively avoids power supply instability and high-value equipment damage caused by three-phase load unbalance.

3.4 Superior Environmental Adaptability & Structural Durability

The whole machine adopts thickened steel plate welding and multi-layer anti-corrosion electrostatic spray treatment, with excellent waterproof, dustproof, rust-proof and anti-aging performance. This 10kV/400V oil immersed transformer can operate stably in outdoor substation stations, heavy industrial zones, coastal humid environments and high-temperature field environments all year round. The reinforced internal core and winding structure enhances vibration resistance and strong short-circuit impact resistance, effectively reducing equipment failure rate and improving overall operational safety and stability under long-term heavy-load conditions.

3.5 Low Maintenance & High Comprehensive Cost Performance

Designed with a robust and reliable mechanical structure, this large-capacity oil immersed power transformer has no easily damaged components and requires minimal routine maintenance. The fully sealed maintenance-free design extends the replacement cycle of insulating oil, greatly reducing daily inspection workload and later operational and maintenance costs. Compared with large-capacity dry-type electrical transformers, it features lower procurement cost, stronger overload tolerance and wider environmental adaptability, achieving ultra-high comprehensive cost performance for heavy-load industrial and municipal power distribution projects.

3.6 Safe & Low-noise Environmental Operation

Optimized core vibration reduction and high-strength winding fixing technology effectively weaken operating vibration and running noise, fully meeting urban and industrial environmental protection noise standards. Equipped with standard oil level gauge, real-time temperature detector and automatic pressure relief valve, the transformer supports real-time operational status monitoring. In case of overload, overheating or internal short-circuit faults, the pressure relief device releases internal pressure timely to avoid equipment damage, ensuring safe and stable operation of the entire large-scale power distribution network.

4. Core Product Uses

As essential large-capacity power transformation equipment for 10kV high-load power grid systems, the 1250kva 10kv 400v Oil Immersed Transformer Electrical Transformers undertake core functions of heavy-duty voltage conversion, centralized large-scale power distribution and high-precision power quality optimization, ensuring safe, efficient and stable operation of heavy-load industrial and municipal power consumption systems:

10kV to 400V Heavy-duty Step-down Voltage Conversion: The core function is to convert 10kV medium-voltage high-capacity grid transmission power into standard 400V three-phase low-voltage power, realizing safe and precise voltage matching between high-voltage main lines and large industrial equipment and municipal centralized power consumption terminals.

Centralized Large-scale Regional Power Distribution: This oil immersed electrical transformer undertakes centralized power distribution tasks for large industrial parks, urban core business districts and large residential cluster areas, reasonably distributing high-capacity grid power according to peak load demand, balancing three-phase heavy load current and reducing large-scale power transmission line loss and voltage drop.

High-precision Power Supply Quality Stabilization: By adjusting off-load tap positions, the equipment calibrates system voltage deviation caused by long-distance transmission loss and frequent peak load changes, stabilizes terminal 400V voltage within standard range, suppresses grid harmonics and three-phase unbalance, and comprehensively improves regional high-load power supply quality and operational stability.

Large Grid Fault Isolation & System Safety Protection: It effectively isolates the upper 10kV medium-voltage main grid and lower 400V heavy-load low-voltage system, preventing high-voltage fault surges from spreading to large-scale user terminals, limiting grid fault scope and reducing batch industrial equipment damage risks.

Long-term Heavy-load Continuous Power Guarantee: Relying on excellent heat dissipation performance and strong short-term overload resistance, the 1250kVA oil immersed transformer supports 24-hour uninterrupted heavy full-load operation, meeting stable power demand for large-scale industrial continuous production and urban core public infrastructure.

5. Wide Application Scenarios

With large load capacity, stable heavy-duty performance, strong environmental adaptability and high comprehensive cost performance, the 1250kva 10kv 400v Oil Immersed Transformer Electrical Transformers are widely applied in urban core power grids, large industrial bases, commercial complex power supply and large-scale new energy supporting projects worldwide:

5.1 Urban Core & Economic Zone Power Grid Construction

This 1250kVA 10kV/400V oil immersed transformer is the core supporting equipment for urban new district power grid construction, old urban central area grid upgrading and economic zone centralized power distribution. It effectively improves regional power grid heavy-load carrying capacity, solves insufficient power supply capacity of traditional small-capacity transformers, and ensures stable power supply for urban core functional areas.

5.2 Large Industrial Park & Heavy Industry Power Supply

Widely used in large manufacturing industrial parks, mechanical equipment manufacturing bases, chemical industrial zones, building material factories and continuous production light & heavy industrial clusters. The 1250kVA large load capacity fully meets 24-hour continuous power demand of large-scale production lines and heavy mechanical equipment, ensuring uninterrupted industrial production power supply.

5.3 Large Commercial & Public Infrastructure Facilities

Suitable for power distribution of urban large commercial complexes, comprehensive shopping malls, large hospital clusters, university campuses and municipal public service centers. Its low-noise, energy-saving and ultra-stable heavy-load operation will not affect public operation and service environments, fully meeting high-standard power supply requirements of large municipal public infrastructure.

5.4 Large-scale Distributed New Energy Grid Connection

Applicable for supporting power transformation and grid connection of large distributed photovoltaic power stations, centralized wind power generation zones and comprehensive new energy power supply projects. The stable heavy-load voltage conversion performance effectively balances new energy power fluctuation and peak power demand, ensuring safe grid connection and stable power transmission of large-scale new energy systems.

5.5 Key National Infrastructure & Large Engineering Projects

With strong outdoor weather resistance, overload resistance and stable heavy-load performance, this oil immersed electrical transformer is widely used for fixed power guarantee of transportation hub projects, water conservancy hub projects, large municipal key projects and industrial base supporting projects, providing reliable long-term stable power support for large-scale infrastructure operation.

6. Frequently Asked Questions (FAQ)

Q1: What scenarios are suitable for the 1250kVA 10kV/400V oil immersed transformer?

The 1250kVA large capacity is specially designed for heavy-load power distribution scenarios that small and medium-capacity transformers cannot support. It is the best choice for urban core grid construction, large industrial parks, commercial complexes and large public facilities with high peak power consumption and 24-hour continuous power demand. As a standard 10kV grade oil immersed electrical transformer, it adopts professional ONAN oil circulation cooling technology, with better heavy-load heat dissipation and outdoor adaptability than dry-type transformers, and can maintain stable operation under long-term full-load and intermittent overload conditions, which is irreplaceable for large-scale power supply projects.

Q2: What is the difference between Dyn11 and Yyn0 connection groups for this 1250kVA heavy-duty transformer?

The two vector groups correspond to different heavy-load grid operation requirements. The Dyn11 connection group has low zero-sequence impedance and excellent suppression effect on three-phase unbalanced load and harmonic current, which is more suitable for large industrial parks and new energy grid connection scenarios with high power quality requirements and complex load types. The Yyn0 connection group features simple structure and ultra-stable voltage output, more applicable to urban municipal power grids and large public facility power distribution with relatively balanced load. We can configure the connection group freely according to customers’ on-site grid conditions and actual load characteristics.

Q3: How to maintain the 1250kva 10kv 400v oil immersed electrical transformer in daily operation?

This fully sealed large-capacity oil immersed transformer belongs to low-maintenance industrial electrical equipment. In daily operation, users only need to regularly check the oil tank sealing status to prevent insulating oil leakage, clean radiator surface dust to ensure unobstructed heat dissipation, and monitor three-phase voltage and current balance to avoid long-term overload operation. Professional inspection teams are recommended to conduct a comprehensive insulating oil quality test, internal component inspection and performance calibration every 2 to 3 years. With standardized routine maintenance, the equipment can achieve a 25-year stable service life, greatly reducing long-term equipment replacement and operational costs for large projects.