Magnetic voltage transformers ordinary two winding type used for l. High voltage instrument transformers for outdoor operation pfiffner has been producing instrument transformers for more than 80 years. Voltage instrument supporting transformer vtd 25 kpb intra. Instrument voltage transformers it applies generally that a voltage transformer may not be operated till a short circuit and, if it takes place, an explosion follows very shortly after it. Instrument transformers for low voltage applications are produced according national and international standards. A calibration system for instrument transformers with.
The transformers can be officially calibrated and are supplied with the appropriate certificates. Ritz offers 600v current and voltage transformers for utility customers. High voltage instrument transformers for outdoor operation. The excellence of our designs comes from our own knowledge and experience in the field as well as from. The instruments can be provided with high voltage protectors protecting the surrounding distributing system.
Voltage transformers voltage transformers are connected across the points at which the voltage to be measured. The devices perform their tasks in electric plant day and night, summer and winter. Thousands voltage transformers are in service worldwide, in all types of climates and under the most severe conditions. Current and voltage instrument transformers are used. Instrument transformers are used in ac system for measurement of electrical quantities i.
Our instrument transformers meet the requirements of the interna tional customers and are designed for a service life of. Medium voltage instrument transformers are to be installed in grids for voltage levels from 3,6 to 52 kv. Current, voltage and combined transformers, oilpaper or gas insulated up to 800 kv. Our range of products includes current and voltage transformers as well as summation and intermediate current transformers.
Instrument transformers 600 volt auxiliary current and voltage transformers drytype open construction auxiliary current transformers for summation and ratio correction applications are available in current ranging from 0. Transformers used for voltage potential measurement steps down the voltage to the level of voltmeter. Current transformers oilpaper, gas and dry insulation range arteche current transformers are named with the letters ca topcore type, oilpaper ch hairpin type, oilpaper, cg gas type or cx dry type followed by 2 or 3 numbers indicating the maximum service voltage for which they have been. Product overview high voltage instrument transformers. Instrument transformers are an essential link for the safe and efficient operation of transmission networks. Current and voltage transformers, insulators and wall bushings. Final solutions with respect to standardization of the. The merging unit can be part of one of the transducers in the field or may be a separate unit e. Voltage transformers vts are also classified along with current transformers cts as instrument transformers. Current transformers, inductive voltage transformers, capacitive voltage transformers, combined currentvoltage transformers and station service voltage transformers are designed to transform high current and high voltage levels down to low current and low voltage outputs in a known and accurate proportion specified by the. High voltage instrument transformer agile magnetics, inc.
Instrument transformers convert signal levels from dangerous high voltage or inconvenient high current, or current at high voltage to levels appropriate for metering. Figure 1 shows some of the most basic uses for instrument transformers. Schneider electric instrument transformers steven engineering. Today nonconventional current and voltage transformers have achieved high performance. The insulating function of high voltage instrument transformers. Instrument transformers are one kind of special transformers what are widely used to efficiently test large unit quantities, requiring a high throughput in the test bay.
Oilpaper insulation model ca model highest voltage kv rated insulation level standard creepage distance mm dimensions weight power kg frequency kv lightning impulse bil kvp switching impulse kvp a. Protection its require linearity in a wide range of voltages. Medium voltage outdoor instrument transformers, with dry or oilpaper insulation from 17 kv up to 72. Current and voltage potential instrument transformers instruction for installation, use and maintenance. Voltage transformers are most commonly used to lower the high line voltages down to typically 120 volts on the secondary to be connected to a voltmeter, watthour meter, or protection relay. Designs consist of cast, case, tapewrapped, and boardmounted technologies. The otef is a tanktype potential transformer with post insulator. Arteche offers a wide range that covers all our customers needs. The reliability and security of trench oilinsulated instrument transformers is based on 100 years of. The designs take into account the harshest environmental conditions of temperature, vibrations and electromagnetic compatibility. Used in ac system for the measurement of current, voltage, power and energy. Abb high voltage instrument transformers 5 high voltage oilfilled products type name voltage level description current transformers cof 25 161 kv substation class oilfilled top core current transformer for metering or relaying application. Instrument transformers convert the currents and voltages of the h. Service is 12470y7200 volts and rated 400 amps vts are connected phase to neutral 7200.
Current transformer instrument transformers engineering360. Arteche has some other technologies to complete the high voltage outdoor service product range, such as. Basic function of instrument transformers is to step down the ac system voltage and current. Hv instrument transformers are used in ac systems for the measurement of electrical quantities, such as current, voltage, power, energy, power. Medium voltage instrument transformers up to 69 kv. There are three main types of voltage transformers. Nov 17, 2019 instrument transformers are used in ac system for measurement of electrical quantities i. A potential transformer is a conventional transformer having primary and secondary windings. Instrument transformers for lowvoltage applications are produced according national and international standards. Our wide range of power voltage transformers from 66400kv combining an instrument voltage transformer and power transformer having the following features. Ritz offers a widearray of 600v instrument transformers for utility and oem customers. The harmonic magnitude and phase angle measurements errors are. Instrument transformer technologies voltage and current. Instrument current and voltage transformers part 2 photo credit.
Similarly, current transformers take a high current. Medium voltage outdoor instrument transformers current, voltage and combined transformers, dry or oilpaper insulation up to 72. Instrument transformer basic technical information and. Designs include castresin and filledcase designs and can be produced to all international standards. Ct testing primary insulation resistance dielectric withstand secondary insulation resistance secondary burden saturation ratio and polarity primary ins.
Maximum allowed torque for screw connection of voltage transformer is 20 nm. Instrument transformers high voltage 15 primary currents. Current and voltage instrument transformers instruction for. Gasinsulated instrument transformer for enhanced safety and reliability. Voltage transformers are most commonly used to lower the high line voltages down to typically 120 volts on the secondary to be connected to a voltmeter, watthour. After crosslinking at high temperatures, the epoxy mixture takes on excellent insulating characteristics and. Voltage transformers are also available in this same construction. They are designed for measuring and protection of high voltage distributing equipment for indoor design. They are either encapsulated by a high grade flame selfextinguishing polycarbonate housing or resin impregnated. In addition, the digital output complies with the most stringent requirements of protective relays and meters. Samgor offers optimally matched test systems for ac and impulse voltages, as well as the required measurement systems for highaccuracy measurements of partial discharges, c. Abbs high voltage gis were first equipped and delivered with ncits in 1998.
Pdf influence of instrument transformers on harmonic. Tg is a gasinsulated high voltage current transformer based on a topcore design, able to withstand current up to 4,000 a and designed for voltages from 72. Current transformer generally current transformers and ammeters are used together as a matched pair in which the design of the current transformer is such as to provide a maximum secondary current corresponding to a fullscale deflection on the. Our large selection of lowvoltage instrument transformers provide an optimal solution for all applications. Low voltage instrument transformers application note core balance current transformers network current from 1 to 4000a inner diameter from 33 x 23 mm to dia 450 mm indoor or outdoor installation depending on model technical data highest voltage for equipment 0,72 kv powerfrequency withstand voltage 3 kv netwok current ipn 1 to. Instrument current voltage transformers part 1 photo credit. We also offer specially designed and custombuilt solutions for your specific applications. Founded in 1972, instrument transformer technologies itt previously known as electroresin transformer construction etc has progressed in line with the growth of electrical industry in south africa and is today a prime supplier of transformers to the south african, african and international transmission, generation and distribution industry. Physical unit used to do the time coherent combination of the current andor voltage data coming from the secondary converters. Instrument transformers are also used with protective relays for protection of power system. Current and voltage potential instrument transformers. Hv instrument transformers or high voltage instrument transformers are designed to measure and convert high current and high voltage to low current and low voltage according to the transformer ratio. Nonconventional instrument transformers in high voltage. Current transformers and voltage transformers example.
Current, voltage and combined transformers, dry insulation up to 72. Current,voltage,instrument transformers kappa electricals. Kappa electricals manufacturers of current transformers,insturment transformers,voltage transformers in india. Our high voltage instrument transformers are just like they sound, transformers built for instrumentation, which needs to be isolated from the high voltage or high current circuits that they measure andor control. Cts current transformers pts potential transformers. The paper presents the behavior of the voltage and current instrument transformers at higher frequencies above 50 hz or 60 hz. They provide accurate and reliable current and voltage measurements for secondary equipment such as meters, protections relays, bay computers and other. The failure of several high voltage instrument transformers during inservice prompted tenaga nasional berhad tnb to identify more effective diagnostic tool to predict insulation breakdowns. They are insulated with oil impregnated paper or high quality epoxy resin. Available from 25 kv to 800 kv for measurement, protection and control. Low voltage instrument transformers twb sa instrument. After crosslinking at high temperatures, the epoxy mixture takes on excellent insulating characteristics and required mechanical features. Combined power and instrument vt instrument transformers. High voltage measurement current and voltage transformers.
The primary reason for use of high voltage instrument transformers is the necessity of insulating instruments and relays from the line voltage. Low voltage instrument transformers deutsche messe ag. Instructions types jkw150 to jkw350 super bute current transformers. The measurement principle of abbs ncit is based on rogowski coil for current and capacitive divider for voltage measurement. Thousands voltage transformers are in service worldwide, in all types of. Current transformers, inductive voltage transformers, capacitive voltage transformers, combined current voltage transformers and station service voltage transformers are designed to transform high current and high voltage levels down to low current and low voltage outputs in a known and accurate proportion specified by the.
Low voltage instrument transformers bar primary current transformers ta series primary current from 100 to 8000 a for busbar up to 4 bars 160 x 5 mm insulation 0. Primary bar assembly for type jado current transformer. Condition assessment of instrument transformer by partial. Voltage instrument supporting transformer vtd 25 kpb. Up to 550kv oil filled, outdoor, post type, voltage and current transformers for distribution substations, protection and metering.
Twb sa manufactures all types of low voltage instrument transformers, current and voltage, 0. Twb sa designs, develops and manufactures, since 1971, exclusively, drytype medium and low voltage instrument transformers up to 36 kv and 3000 a, current and voltage for indoor and outdoor application. Kappa electricals manufacturers of current transformers,insturment transformers, voltage transformers in india. Current transformers oilpaper, gas and dry insulation 1. We provide voltage transformers sometimes referred to as potential transformers or pts in three different sizes and for both protection and measurement applications. Instructions for type apt potential current transformers. These are shunt connected devices intended to reproduce secondary voltages in fixed proportion to the primary system voltage. Resistance test for bar and primary wound cts dc voltage test at the rated crest voltage on the primary winding secondary grounded 1 minute test. Try our range of indoor one or three phase, resin encapsulated or oil filled draw out voltage transformer or current transformers complete with high voltage and low voltage fuses. Iii 600vrms 600vrms 600 vrms 600vac output termination jack 5 ft lead jack 6. Voltage instrument transformers vtd 25 are singlephase transformers isolated with doublepoles. The current and voltage transformers can be calibrated for different countries and delivered with the corresponding certificate. Oip insulated outdoor products are subjected to extreme climatic conditions and hence extra care is taken in the design and manufacturing of such transformers.
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