Transformer Nameplate Data – Explain the Rating and Features
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
- Frequency
- 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
Related Posts:
- 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 |
| 1 | Manufacturer’s Name: | ABB/206788 |
| 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 |
| 8 | Rated Frequency: | 50Hz |
| 9 | Rated Voltages: | HV 33 kV, LV 11 kV, |
| 10 | Rated Currents | HV______,LV_______. |
| 11 | Vector Group Symbol | __________________ |
| 12 | % Impedance Voltage
.. ( At Rated Current) |
__________________ |
| 13 | % Reactance Voltage in % : | __________________ |
| 14 | Types of Cooling | ONAN |
| 15 | Total Weight
.. Mass or insulating Oil .. Transportation Weight .. Untanking Weight |
__________Kg
__________Kg __________Kg __________Kg |
| 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 |
__________
kV(rms) |
| 20 | Other | ……………………. |
Also shown in below image.
Below is a 100kVA (Three-Phase) Transformer nameplate.
Click image to enlarge.
Related Posts:
- Types of Transformers and Their Applications
- Parallel Operation of Single-Phase & Three-Phase Transformers
- Difference Between Current Transformer & Potential Transformer
- What is Potential Transformer (PT)? Types & Working of Voltage Transformers
- Transformer Formulas and Equations
- What is the Transformer’s Voltage Regulation?
- Open Delta Connections of Transformers
- Transformer Performance & Electrical Parameters
- Power Transformer Protection and Faults
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Hi,<br />Very good blog post I love your site keep up the great posts.
Thanx for appreciation
In some transformers the ratings are having two MVAs …for example- 10/12.5 MVA …can anyone explain me
If the transformer has two type of cooling method, for example ONAN/ONAF , those ratings are at each conditions!! that is first in first cooling method and second in second cooling method!
I agree! thanks for this information.
Thanx for appreciation
Hi, On some plates we can see Y/delta ikons with triangle. Would you explain me, pls, what is that dash-line inside of triangle sign for?<br />Thanks<br />
DDS-84-2007 ?<br />What is that notation?<br />Is that a standard in which transformer built or some type of manufacturing number or date in which the transformer is built?
Where is that data???
thanks, can we find efficiency and iron losses in name plate?
Generally, it is not given by nameplate… Read about Transformer Efficiency here<br /><a href="https://www.electricaltechnology.org/2013/12/transformer-efficiency-all-day-efficiency-and-condition-for-maximum-efficiency.html" rel="nofollow"> Transformer Efficiency, All day Efficiency & Condition for Maximum Efficiency<br /></a> <br />
where is insulation level ?
<a href="http://www.runthalaindustries.com/" rel="nofollow">Electrical transformer manufacturers</a> provides different content notation on name plate. This blog provides standard name plate notification of the transformer thanks for sharing imaging information about name plate. <br /> <br />
how we get Transformers tolerance
40 MVA transformer also called 20 26 ( May be Size or some else, i don’t know ) Can anyone told me that what is 20 26? i mentioned a cell no in the comment for text messaging or What’s app .. +92-306-6287879
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Dear sir/madam,
I have a 34.5kV ,100KVA distribution transformer with 5 taps .The nameplate has the following as the primary voltage : 34.5+/-2×2.5% kV.what does this mean
Kweku
Metering to be done at 33KV HT line side and for 5MVA transformer maximum current is 90A therefore provided CT ampere ratio is very high please clarify…?