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Views: 0 Author: Site Editor Publish Time: 2026-07-17 Origin: Site
Project Background
In 2026, a power engineering contractor contacted ZISHENG for a distribution transformer to support a new commercial power distribution project. The transformer would be installed outdoors and connected to the local 11kV distribution network. The customer required stable performance, low operating losses, and a short delivery time to meet the project schedule.
After reviewing the electrical drawings and operating conditions, our engineering team recommended a 630kVA oil-immersed distribution transformer designed in accordance with IEC 60076.
Item | Specification |
|---|---|
Product Type | Oil-Immersed Distribution Transformer |
Rated Capacity | 630 kVA |
Rated Voltage | 11kV / 0.4kV |
Frequency | 50 Hz |
Phase | Three Phase |
Cooling Method | ONAN |
Vector Group | Dyn11 |
Tapping Range | ±2 × 2.5% |
Insulation Class | Class A |
Standard | IEC 60076 |
Installation | Outdoor |
The transformer tank was manufactured from welded steel plates with an anti-corrosion coating suitable for humid and tropical environments. All sealing points were pressure-tested before shipment to reduce the risk of oil leakage during transportation and long-term operation.
To improve operating efficiency and reduce energy loss, the transformer was built with cold-rolled grain-oriented (CRGO) silicon steel laminations. The core joints were carefully assembled to minimize no-load losses and noise.
The windings were made from high-conductivity electrolytic copper, with insulation materials selected to withstand long-term thermal stress. The winding structure was designed to improve mechanical strength under short-circuit conditions while maintaining stable electrical performance.
Production followed the standard workflow used in our factory.
CRGO core cutting and stacking
Low-voltage and high-voltage coil winding
Coil assembly and insulation
Core-and-coil assembly
Vacuum drying
Tank assembly
Transformer oil filling under vacuum
Final assembly
Routine factory testing
Each stage was inspected before moving to the next production step to ensure dimensional accuracy and assembly quality.
Before shipment, the transformer completed routine tests in accordance with IEC 60076, including:
Winding resistance measurement
Voltage ratio and vector group verification
No-load current and no-load loss test
Load loss and impedance voltage test
Applied voltage test
Induced overvoltage test
Insulation resistance measurement
Oil leakage inspection
The corresponding factory test report was issued before delivery.
After testing, the transformer was packed for export using moisture protection and reinforced fastening to reduce movement during transportation.
The customer completed installation according to the project schedule. Following commissioning, the transformer was connected to the local distribution network and placed into normal operation.
The transformer was selected to supply power for commercial facilities connected to the local distribution system.
The customer chose this configuration because it offered:
Stable voltage performance
Compact structure for outdoor installation
Low maintenance requirements
Compliance with IEC standards
Compatibility with the existing 11kV distribution network
The project was completed within the planned delivery schedule, and all required technical documents were provided before shipment.
CRGO silicon steel core for reduced no-load losses
Copper windings with high electrical conductivity
ONAN natural oil cooling
Dyn11 vector group
Vacuum oil filling process
Factory routine tested before shipment
Designed according to IEC 60076
Suitable for power distribution, industrial plants, commercial buildings, and infrastructure projects
