Oil immersed transformers produced by South China Electric mainly include power transformers and special transformers. The range of these transformers is 0-35kV and 0-20,000 kVA. In addition, our oil immersed distribution transformers are produced in strict compliance with the IEC60076 international power transformer standard.

Cores
According to different adopted material and structure, there are totally three core types: laminated silicon steel core structure, silicon steel wound core structure and amorphous alloy core structure. All of our products use cold-rolled grain oriented (CRGO) silicon steel as a magnetic conductive material and adopt a multiple-step laminated structure. The amorphous alloy core is produced from high quality amorphous alloy materials, mainly used in low-loss distribution transformer of 0-1,600 kVA.

Windings
High and low voltage windings are made of oxygen-free copper wires. High voltage windings have cylinder structure, sectional cylinder structure and pancake winding structure. Low voltage windings have four following structures: cylinder, spiral, foil and pancake structure. We adopt different mode and structure of high and low voltage windings in accordance with the transformer capacity and voltage class as well as the electric, machinery and cooling requirement. By doing this, we ensure a good capacity of our transformers for withstanding voltage surge and short circuit.

Tap changers
Our company provides off load and on load tap changer.
The off load tap changer is suitable for small-capacity transformers. It has two voltage regulating options: 3 and 5 position. This kind of tap changer must be operated when the transformer is de-energized.
The on load tap changer is applicable for large-capacity transformers, especially for those with strong voltage fluctuations. Its voltage regulating range is 7, 9, 11 and 17 position. You can conduct living working with CF, S and V type tap changer.

Tanks
Our oil immersed transformers mainly consist of three types: corrugated tank, barrel-type tank and bell-type tank. The corrugated tank is especially designed for 0-1,600 kVA transformers, barrel-type tank for 2,000-10,000 kVA and bell-type tank for 12,500-20,000 kVA. All tanks utilize the automatic electrical arc welding technique, preventing leakage under various operating condition. In the pretreatment process, the corrugated tank adopts pickling and parkerising technique. When it comes to large-scale tanks, we will adopt sandblasting technique. In the paint spraying process, we adopt three protective layers: primer, middle coating and finishing coat, providing a good capacity of anti-corrosion. If necessary, we also provide hot dip galvanized method according to the working condition. The tank is covered with high quality sealed material and must undergo strict leakage test, offering a strong guarantee of zero leakage. The newly fin radiator and corrugated tank greatly improve the appearance. In addition, clients are able to choose the primer colors.

Bushings
Our porcelain bushings have four voltage ranks: 1kV, 10kV, 20kV and 40.5kV. The elbow cable connector is perfect for use in products with a voltage under 10kV. According to different structure, our bushings can be installed on the transformer cover or tank wall. The terminal intervals can also be set if needed.
Other designs are also available on request.

Standard Accessories
Oil conservator（available on request, usually for transformers above 2,000kVA）
Temperature indicator (for transformers above 1,000 kVA)
Pressure relief valve
Oil level indicator
Oil feeding/drain valve
Oil sample valve
Grounding device
Lifting device
Cable box (available on request)

Tests
All products produced by South China Electric have passed routine test, type test and special test conducted by national labs. All power machines are designed and produced in strict compliance with international standards and client requirement. Non-conforming products will be picked out. The routine tests our oil immersed transformers must undergo are as follows:
Voltage ratio and connection group test
Load loss and short circuit impedance measurement
No-load loss measurement
Power frequency withstand voltage test
Induced over voltage test
On load tap changer test (especially for on load regulating transformers)
Transformer oil test
Tank leakage test
Temperature rise test
Lightning impulse test
Partial discharge measurement

Manufacturing Process