Instructions for type apt potential current 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. The instruments can be provided with high voltage protectors protecting the surrounding distributing system. The otef is a tanktype potential transformer with post insulator. Voltage transformers are also available in this same construction.
Generally, the metering its require high accuracy in the range of normal oper ating voltage and current. The primary reason for use of high voltage instrument transformers is the necessity of insulating instruments and relays from the line voltage. Instrument transformers are used in ac system for measurement of electrical quantities i. 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. High voltage instrument transformer agile magnetics, inc. Kappa electricals manufacturers of current transformers,insturment transformers,voltage transformers in india. Instrument transformer basic technical information and. Ritz offers a widearray of 600v instrument transformers for utility and oem customers. The excellence of our designs comes from our own knowledge and experience in the field as well as from. Ritz offers 600v current and voltage transformers for utility customers. They are either encapsulated by a high grade flame selfextinguishing polycarbonate housing or resin impregnated.
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. Similarly, current transformers take a high current. Instrument transformers are an essential link for the safe and efficient operation of transmission networks. Instrument transformers convert signal levels from dangerous high voltage or inconvenient high current, or current at high voltage to levels appropriate for metering. 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. Instructions types jkw150 to jkw350 super bute current transformers. Current and voltage instrument transformers instruction for.
Voltage instrument transformers vtd 25 are singlephase transformers isolated with doublepoles. Basic function of instrument transformers is to step down the ac system voltage and current. We provide voltage transformers sometimes referred to as potential transformers or pts in three different sizes and for both protection and measurement applications. 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. Used in ac system for the measurement of current, voltage, power and energy. Physical unit used to do the time coherent combination of the current andor voltage data coming from the secondary converters. 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. The current and voltage transformers can be calibrated for different countries and delivered with the corresponding certificate. Today nonconventional current and voltage transformers have achieved high performance. High voltage instrument transformers for outdoor operation pfiffner has been producing instrument transformers for more than 80 years. Voltage transformers vts are also classified along with current transformers cts as instrument transformers. Ct testing primary insulation resistance dielectric withstand secondary insulation resistance secondary burden saturation ratio and polarity primary ins.
The paper presents the behavior of the voltage and current instrument transformers at higher frequencies above 50 hz or 60 hz. Maximum allowed torque for screw connection of voltage transformer is 20 nm. The harmonic magnitude and phase angle measurements errors are. Our instrument transformers meet the requirements of the interna tional customers and are designed for a service life of. We also offer specially designed and custombuilt solutions for your specific applications. Instrument transformer technologies voltage and current. 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. Primary bar assembly for type jado current transformer. Hv instrument transformers are used in ac systems for the measurement of electrical quantities, such as current, voltage, power, energy, power. Arteche has some other technologies to complete the high voltage outdoor service product range, such as.
Current and voltage instrument transformers are used. Instrument transformers for low voltage applications are produced according national and international standards. Instrument transformers are also used with protective relays for protection of power system. Instrument transformers high voltage 15 primary currents. Cts current transformers pts potential transformers. 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.
Current and voltage potential instrument transformers instruction for installation, use and maintenance. Medium voltage instrument transformers up to 69 kv. Abbs high voltage gis were first equipped and delivered with ncits in 1998. In addition, the digital output complies with the most stringent requirements of protective relays and meters.
Our range of products includes current and voltage transformers as well as summation and intermediate current transformers. The insulating function of high voltage instrument transformers. Twb sa manufactures all types of low voltage instrument transformers, current and voltage, 0. 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.
Product overview high voltage instrument transformers. 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. 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. Available from 25 kv to 800 kv for measurement, protection and control. 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. After crosslinking at high temperatures, the epoxy mixture takes on excellent insulating characteristics and. 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. The ct vt range is part of a comprehensive offer of products that are perfectly coordinated to meet all medium and low voltage electrical distribution requirements. Voltage instrument supporting transformer vtd 25 kpb intra. 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.
Nonconventional instrument transformers in high voltage. Voltage instrument supporting transformer vtd 25 kpb. Medium voltage outdoor instrument transformers current, voltage and combined transformers, dry or oilpaper insulation up to 72. Low voltage instrument transformers deutsche messe ag. Designs include castresin and filledcase designs and can be produced to all international standards. Up to 550kv oil filled, outdoor, post type, voltage and current transformers for distribution substations, protection and metering. Our wide range of power voltage transformers from 66400kv combining an instrument voltage transformer and power transformer having the following features. Ge manufactures a complete range of high voltage oilfilled voltage transformers vts. Schneider electric instrument transformers steven engineering. 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. Porcelain insulator with high creep and high strike design polymer as an option. Current transformers oilpaper, gas and dry insulation 1. Current transformers and voltage transformers example. Medium voltage instrument transformers are to be installed in grids for voltage levels from 3,6 to 52 kv.
Combined power and instrument vt instrument transformers. A calibration system for instrument transformers with. They provide accurate and reliable current and voltage measurements for secondary equipment such as meters, protections relays, bay computers and other. Iii 600vrms 600vrms 600 vrms 600vac output termination jack 5 ft lead jack 6. A potential transformer is a conventional transformer having primary and secondary windings. The measurement principle of abbs ncit is based on rogowski coil for current and capacitive divider for voltage measurement. After crosslinking at high temperatures, the epoxy mixture takes on excellent insulating characteristics and required mechanical features. 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.
Kappa electricals manufacturers of current transformers,insturment transformers, voltage transformers in india. Instrument current voltage transformers part 1 photo credit. Agile magnetics produces costefficient and spacesaving custom high voltage instrument transformers available in full range of materials and configurations. Instrument current and voltage transformers part 2 photo credit. Arteche offers a wide range that covers all our customers needs. 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. The designs take into account the harshest environmental conditions of temperature, vibrations and electromagnetic compatibility. The reliability and security of trench oilinsulated instrument transformers is based on 100 years of. High voltage instrument transformers for outdoor operation. Nov 17, 2019 instrument transformers are used in ac system for measurement of electrical quantities i. They are insulated with oil impregnated paper or high quality epoxy resin. Instrument transformers for lowvoltage applications are produced according national and international standards.
Oip insulated outdoor products are subjected to extreme climatic conditions and hence extra care is taken in the design and manufacturing of such transformers. Designs consist of cast, case, tapewrapped, and boardmounted technologies. Service is 12470y7200 volts and rated 400 amps vts are connected phase to neutral 7200. These are shunt connected devices intended to reproduce secondary voltages in fixed proportion to the primary system voltage. Gasinsulated instrument transformer for enhanced safety and reliability. Current and voltage transformers, insulators and wall bushings. Medium voltage outdoor instrument transformers, with dry or oilpaper insulation from 17 kv up to 72. Figure 1 shows some of the most basic uses for instrument transformers. Thousands voltage transformers are in service worldwide, in all types of climates and under the most severe conditions.
Samgor offers optimally matched test systems for ac and impulse voltages, as well as the required measurement systems for high accuracy measurements of partial discharges, c. There are three main types of voltage transformers. They are designed for the use in the high voltage systems. Instrument transformers are high accuracy class electrical devices used to isolate or transform voltage or current levels. The merging unit can be part of one of the transducers in the field or may be a separate unit e. Instrument transformers convert the currents and voltages of the h. Current,voltage,instrument transformers kappa electricals. Transformers used for voltage potential measurement steps down the voltage to the level of voltmeter. Pdf influence of instrument transformers on harmonic.
The explosion results in consequent damage of adjacent equipment. Low voltage instrument transformers twb sa instrument. They are designed for measuring and protection of high voltage distributing equipment for indoor design. 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. 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. 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. 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. Protection its require linearity in a wide range of voltages. Current, voltage and combined transformers, dry insulation up to 72. Magnetic voltage transformers ordinary two winding type used for l. The devices perform their tasks in electric plant day and night, summer and winter.
High voltage measurement current and voltage transformers. Thousands voltage transformers are in service worldwide, in all types of. Voltage transformers voltage transformers are connected across the points at which the voltage to be measured. Current transformer instrument transformers engineering360.
Our large selection of low voltage instrument transformers provide an optimal solution for all applications. Our large selection of lowvoltage instrument transformers provide an optimal solution for all applications. The transformers can be officially calibrated and are supplied with the appropriate certificates. Current, voltage and combined transformers, oilpaper or gas insulated up to 800 kv. 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. Condition assessment of instrument transformer by partial.
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