7Transformer
Transformer is one of the most efficient machine or device in the world. It uses the electromagnetic induction principle to change the voltage of an AC power. The turn ratio or voltage ratio of transformer is a fix value except for variable transformer which can be adjusted.
Based on the physical construction and cooling method of the transformer, there are 3 main categories of transformer which are:
| A |  |
Dry Type Transformer A dry type transformer is cooled by natural air convection or with additional cooling fans assisted. Generally used for indoor environment and low voltage below 1000V |
| B |  |
Oil Immersed Type Transformer An oil immersed transformer is cooled by insulating oil and natural air convection or with additional cooling fans assisted. Generally used for outdoor environment and all voltages |
| C |  |
Cast Resin Type Transformer A cast resin transformer is cooled by insulatingepoxy resin and natural air convection or with additional cooling fans assisted. Generally used for indoor environment and medium or high voltages. |
According to different applications, there are many types of transformer for selection
| 1 | Step Down Transformer |
| 2 | Step Up Transformer |
| 3 | Isolation Transformer |
| 4 | Ultra-Isolation Transformer |
| 5 | Scott and Le Blanc Transformer |
| 6 | K Rated Transformer |
| 7 | Harmonic Mitigating Transformer |
| 8 | Polyphase Transformer |
| 9 | Auto Transformer |
| 10 | Potential Transformer |
| 11 | Current Transformer |
| 12 | Grounding Transformer |
| 13 | Buck Boost Transformer |
Dry Type Transformer
| Capacity | 5kVA to 50,000kVA |
| Number of Phase | 1 Phase or 3 Phase |
| Operating Frequency | 50Hz, 60Hz, 400Hz, 500Hz up to 10,000Hz |
| Voltage | up to 1,000V |
| Insulation System | Class A, Class E, Class B, Class F, Class H, Class N, Class R, Class S, Class C Class 105, Class 120, Class 130, Class 155, Class 180, Class 200 Class 220, Class 240, Class over 240 |
| Windings | Copper or Aluminum |
| Cooling | Air natural or with fans assisted cooling |
| Termination | Tin-plated copper terminals |
| Installation | Floor mounted, wall mounted, pole mounted, panel mounted |
| Enclosure | Rugged steel enclosure with powder coated finishing or paint finishing suitable for indoor or outdoor use |
Oil Immersed Type Transformer
| Capacity | 5kVA to 50,000kVA |
| Number of Phase | 1 Phase or 3 Phase |
| Operating Frequency | 50Hz, 60Hz, 400Hz |
| Voltage | up to 33,000V |
| Insulation System | Class A, Class E, Class B, Class F, Class H Class 105, Class 120, Class 130, Class 155, Class 180 |
| Windings | Copper or Aluminum |
| Oil | Mineral oil or silicone oil |
| Cooling | Oil natural air natural or with fans forced cooling |
| Termination | Tin-plated copper terminals or porcelain bushings |
| Installation | Floor mounted, wall mounted, pole mounted, panel mounted |
| Tank | Rugged steel tank and cooling fins or radiators with multiple layers paint finishing suitable for indoor or outdoor use |
Cast Resin Type Transformer
| Capacity | 0.5kVA to 5,000kVA |
| Number of Phase | 1 Phase or 3 Phase |
| Operating Frequency | 50Hz, 60Hz, 400Hz, 500Hz up to 10,000Hz |
| Voltage | up to 22,000V |
| Insulation System | Class A, Class F, Class H, Class 105, Class 155, Class 180 |
| Windings | Copper or Aluminum |
| Cooling | Air natural or with fans assisted or forced cooling |
| Termination | Tin-plated copper terminals |
| Installation | Floor mounted, wall mounted, panel mounted |
| Enclosure | Rugged steel enclosure with powder coated finishing or paint finishing suitable for indoor or outdoor use |
