Capacitive voltage transformers

Product catalog summary

General Description: Capacitive voltage transformers (CVTs) of type ECF are designed for high-voltage switchgears ranging from 72 to 550 kV. They convert voltages to standardized values for meters and protective devices. The CVT comprises a condenser unit and an electromagnetic measuring unit (EMu). The condenser unit, located in the insulator, uses a capacitive mixed dielectric impregnated with insulation liquid and is hermetically sealed. A stainless steel expansion bellows compensates for oil volume changes, and a shielding electrode is used for voltages above 420 kV. The EMu, housed in the transformer's foot case, ensures safe transmission of measurement signals and includes a damping unit for increased safety.

Design Advantages: The CVTs offer a cost-effective and reliable design for high voltages, are expandable for high-frequency signal transmission, and require no on-site accuracy adjustments. They are stable in temperature and accuracy over their service life and provide increased safety against relaxation oscillation.

Technical Data: The CVTs conform to IEC/IEEE standards, with highest voltage ratings from 72.5 to 550 kV and rated power-frequency withstand voltages from 140 to 680 kV. They operate at frequencies of 50/60 Hz and have accuracy classes ranging from 0.1 to 6P. The maximum thermal limiting output is ≤ 1000 VA, with a maximum simultaneous burden of 150 VA for class 0.2.

Options and Features: Options include intermediate-voltage earthing switches, power-line-carrier protection, fuses for secondary windings, and secondary terminals in bolt design. The terminal box is designed for easy connection and can include additional safety devices on request.

Highlights: The CVTs are easy to mount, compensate for transient overvoltages, and are expandable for high-frequency signal couplings. The terminal box is secure and customizable, and additional terminal boxes can be added if needed.

Contact Information: PFIFFNER has a global presence with contact details provided for offices in Switzerland, Germany, Turkey, Brazil, and associated companies.

Catalog excerpts

Capacitive voltage transformers Outdoor operation Oil-paper insulated ECF (72 -550) kV Current and voltage - our passion

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Capacitive voltage transformers of type ECF are used in high-voltage switchgears from 72 to 550 kv. They transmit voltages to standardised, equivalent values for meters, measuring and protective devices. The capacitive voltage transformer consists of one condenser unit and one electromagnetic measuring unit (EMu). The condenser unit is located in the insulator and consists of one capacitive mixed dielectric which is impregnated with insulation liquid. This active part is hermetically sealed to the outside. For volume compensation of the oil there is a stainless steel expansion bellows in the...

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Design Primary connection Metal expansion bellows Porcelain or silicone composite insulator High-voltage capacitor Possible options Intermediate-voltage bushing ■■ Lifting lugs Oil level indicator Electromagnetic unit Terminal box with rating plate Compensation reactor Damping unit Aluminium housing Main earth connection Oil drain valve Intermediate-voltage bushing for check measurement during maintenance Power-line-carrier protection – protective device with discharge reactor, overvoltage protection and earthing switch Fuses/overload protectors to protect secondary windings Secondary windings...

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* with standard composite silicone insulator, creepage distance 25 mm/kV

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Highlights High and very high voltage Tone frequency (PLC) couplings ■ Expandable for high frequency signal (PLC) couplings ■ Extendable for the installation of a line trap coil ■ Simple and safe mounting on sitefor transformers which consist of multi-piece condenser units ■ High temperature and precision stability over the entire service life ■ Compensation of transient overvoltages in the grid, caused by circuit breakers ■ The terminal box with the lid to be opened sideways is secured by captive screws. Apart from terminals, fuses, surge arresters, additional contacts, spark gaps and sealable...

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PFIFFNER Instr. Transformers Ltd 5042 Hirschthal Switzerland ® +41 (0)62 7392828 PFIFFNER Technologie Ltd 5042 Hirschthal Switzerland ® +41 (0)62 7392828 PFIFFNER Systems Ltd 4303 Kaiseraugst Switzerland ® +41 (0)61 4676111 PFIFFNER Deutschland GmbH 25524 Itzehoe Germany ® +49 (0)48 21408270 PFIFFNER Transformator A.S. 06750 Akyurt/Ankara Turkey ® +90(0)31 28475521 PFIFFNER do Brasil Ltda 88307-740 Itajai Brazil ® +55 (0)47 33481700 MGC Moser-Glaser Ltd 4303 Kaiseraugst Switzerland ® +41 (0)614676111 ALPHA Elektrotechnik Ltd 2560 Nidau Switzerland ® +41 (0)32 3328700 This document has been drawn...

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Capacitive voltage transformers

Capacitive voltage transformers

Catalog excerpts

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