20+ years professional R&D and production experiences
World-Class Transformers, Smart Solutions
7*24H Service Hotline:
(+86)136 5236 0047
A distribution transformer rating chart provides a visual representation of the various specifications and capacities of distribution transformers used in electrical power distribution systems. These transformers step down the voltage from higher transmission levels to lower voltages suitable for residential, commercial, and industrial consumption. The chart typically includes information such as transformer capacity (in kVA or MVA), primary and secondary voltage ratings, vector groups, cooling types, and sometimes dimensions and weight.
Here's a simplified example of what data you might find in a distribution transformer rating chart:
| Transformer Type | Capacity (kVA) | Primary Voltage (kV) | Secondary Voltage (kV or V) | Vector Group | Cooling Type |
|---|---|---|---|---|---|
| Single Phase | 10, 25, 50, 100 | 11 / 22 | 400V / 230V | Dyn1 | ONAN |
| Three Phase | 50, 100, 200, 500, 1000 | 11 / 22 / 33 | 400V | Dyn11 | ONAN / OFAF |
| Miniature | 1, 2.5, 5 | 11 | 230V | Yyn0 | ONAF |
| Pad-Mounted | 50, 75, 100, 150, 250 | 11 / 22 | 480Y/277V | Dyn1 | ONAN |
| Pole-Mounted | 5, 10, 15, 25 | 7.2 / 11 | 230V / 400V | Dy1 | ONAN |
Notes:
Capacity: Shown in kVA (kilo-Volt-Amps), indicating the transformer's maximum power handling capability.
Primary Voltage: The voltage at which the transformer is connected to the grid or distribution line.
Secondary Voltage: The voltage it steps down to, suitable for consumer connections.
Vector Group: Describes the phase relationship between primary and secondary windings (e.g., Dyn1, Dyn11, Yyn0).
Cooling Type: ONAN (Oil Natural Air Natural), OFAF (Oil Forced Air Forced), ONAF (Oil Natural Air Forced), etc., indicate how the transformer is cooled.
Actual charts can be much more detailed and may also include additional technical specifications like impedance, efficiency, noise level, and more. Welcome to contact Qinghao Electric for precise and up-to-date information.
