1. The transformer core is made of imported high-quality cold-rolled silicon steel sheet, which greatly reduces no-load loss and no-load current. The core is� tightly� bound to ensure the compactness and reduce noise. 2. The high and low voltage windings are� made of oxygen-free copper. The low voltage winding of 500KVA and below is of double-layer cylinder structure,� of 630kVA and above adopt double helix or four helix structure. High-voltage winding adopts multi-layer cylinder structure. 3. Dyn11 is used in the transformer connection group to reduce the influence of harmonics on the power grid and improve the quality of power supply. 4. The transformer is a fully sealed structure, with three coats of primer and one coat of finish paint applied on the inner and outer surfaces. The product is salt fog proof, moisture� proof and fungus-proofing, beautiful, durable and reliable 5. The measured noise value is lower than the standard and maintenance free under normal operation.