General Requirements of a Transformer Nameplate to Show the Characteristics
Following are the minimum information and data printed on a transformer nameplate from the designer and manufactures. The standards require the following information and data for transformers rated above 500 kVA (and 1000kVA = 1MVA.
- Name of manufacturer
- Serial number
- year of manufacture
- Number of phases
- kVA or MVA rating
- Voltage ratings.
- Tap voltages.
- Connection diagram.
- Cooling class
- Rated temperature in °C
- Polarity (for Single Phase Transformers)
- Phasor or vector diagram (For Polyphase or Three Phase Transformers)
- % impedance.
- Approximate mass or weight of the transformer
- Type of insulating liquid.
- Conductor material of each winding.
- Oil volume (of each transformer Container/Compartment)
- Instruction for Installation and Operation
- How to Size a Single Phase and Three Phase Transformer in kVA? Calculator
- Why Transformer Rated In kVA, Not in KW?
Nameplate Rating Of a Transformer
The data on the Nameplate of a transformer contains of kVA rating, Voltage Rating, Frequency, Number of Phases, Temperature, Type of Cooling, % Impedance and Reactance, Name of Manufacture, Year of Manufacture etc.
A Typical Nameplate of a Transformer as follows.
|S.No.||Description of Data to be given||Ra-marks for example|
|2||Manufacture’s Serial Number||224106|
|3||Kind of Transformer||Power Transformer|
|4||Relevant Standard Year||I.S/P.S/B.S/ IEC /DIS/JIS NEMA|
|5||Year of Manufacture||20….|
|6||Number of Phase 3||3|
|7||Rated Power||1000kVA = 1MVA|
|9||Rated Voltages:||HV 33 kV, LV 11 kV,|
|11||Vector Group Symbol||__________________|
|12||% Impedance Voltage
.. ( At Rated Current)
|13||% Reactance Voltage in % :||__________________|
|14||Types of Cooling||ONAN|
.. Mass or insulating Oil
.. Transportation Weight
.. Untanking Weight
|16||Insulating liquid ( if Not Oil) Types:||__________|
|17||Quantity of Oil ( Liters):||__________|
|18||Details about Tap-Changer||__________|
|19||Rated insulation Level:
.. Power-Frequency withstand Voltage
Also shown in below image.
Below is a 100kVA (Three-Phase) Transformer nameplate.
Click image to enlarge.
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