KOTEF Brochure0 pages

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INSTRUMENT TRANSFORMERS

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KOTEF

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Combined Metering Unit

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72.5 to 420 kV

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The KOTEF is designed to provide both current and voltage measurements from a single

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device. It utilizes the same components as the individual CTs and VTs. Both transformers are

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combined in a single metering insulator and are available in porcelain or composite. This is

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an excellent solution for adding metering capability to either a new substation installation

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or a site being upgraded where space is at a premium.

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□ Metering - Protection

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□ Characteristics:

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- High quality paper-oil insulation

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- Oil expansion by stainless steel

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diaphragm bellows

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- Oil level indicator

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- Secondary cores in aluminum box

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- Changing of primary ratio by primary

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series-parallel connection (double or triple

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ratio) or by secondary taps

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□ Earthquake-proof design: The standard

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KOTEF resists medium intensity seismic

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events. For highly active seismic regions,

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the design is adapted accordingly.

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| Alstom Grid Instrument Transformers are installed in the four corners of the world

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□ Compliance with IEC, ANSI/IEEE

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or equivalent standards

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Design and avantages

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As with separate transformers, the current

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transformer part is located in the head housing

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and the voltage transformer part in the base

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tank. The grading layers between high-voltage

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potential and ground potential are arranged

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in opposite directions inside the insulator. The

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base dimensions remain the same as a current

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or voltage transformer of the same nominal

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voltage.

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The CT and VT functions are fulfilled within a

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single unit. Consequently, considerable cost

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savings are realized in the initial purchase price,

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transportation, real estate and installation labor

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and materials compared to the equivalent costs

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of two separate transformers.

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Long service life

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and near zero maintenance

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Insulation integrity is assured by the fact that

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the oil is hermetically sealed from the atmo-

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sphere by a metallic diaphragm assembly. All

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external parts are of corrosion-resistant mate-

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rial. Therefore, regular painting of the metallic

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parts is not required.

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KOTEF have been designed for a 30 year

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lifetime and, thanks to the soundness of our

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technical concepts, many well out-live this

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service life.

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Customer Benefits

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• Price advantage

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• Space saving:

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only one base

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• Cost savings on transporta-

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tion and assembly

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• Near zero maintenance

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• Protection against bursting

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GRID

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