The purpose and function of a Voltage transformer is almost like that of a current transformer except that high voltages are transformed to manageable low voltages to operate metering and protective systems. Generally Voltage Transformer is like a power transformer directly connected to a system line. Separate windings are provided for a metering and protection with different accuracies and voltage factor required for various applications.
DESIGN
Agarwal Industries manufactures the following types of voltage transformers.
1. Single Pole (Neutral Earthed)
2. Double Pole(Line to Line)33KV
3. Three phase (Neutral Floating/Earthed) up to 33KV
On request from users voltage factors varying from 1.2 to 1.9 continuous are offered to suit various system earthing conditions.
PRIMARY and SECONDARY WINDING Modified polyester enamelled copper wires used for winding of primary and secondary. At all stages of winding, care is taken to protect winding to avoid high surge and high voltage stress.
We manufacture two type of designs in CT.
1. Live Tank Design.
2. Dead Tank Design.
As high accuracy is required for measurement purpose and high operating values required for protection purpose, these two functions are met distinctly in a current transformer by providing metering core and protection cores separately with different functional properties. Now a days in view of high cost production of electrical energy, utilities specify very high accuracy class such as 0.5S & 0.2S (as per established standards) which measure energy accurately at a value as low as 1% of the transmitted current.
CONSTRUCTION OF CURRENT TRANSFORMER In addition to the above, a current transformer, being a series element has to withstand large dynamic forces and high thermal stresses during short circuit currents appearing in the lines at the incidence of a faults on the main lines to help clearing of such disturbance as early as possible. Adequate short circuit tests have been conducted on our Current transformers. We also under take to conduct these tests on specific request from buyers. insulation during the process of manufacture endangering insulation, entire process of insulation is carried out in dust free chambers.
Agarwal Industries manufactures Outdoor Oil cooled CTPT combined Metering unit up to 33KV for customer requirements as per IS 2705/1992 & IS 31546/1992, IS 60044(1) & IS 60044(2), and IEC 61869 (1) & IEC 61689(2). Agarwal Industries undertake Design, Manufacture and Supply of Metering Equipment comprising of different ratios with a notion right from LT class up to 33KV Class, an indigenous venture whose Quality matches up to international standards and meeting the stringent tropical service requirements. 11 KV and 33KV CTPT Combined Metering Unit is an oil cooled system. This system can be made in 3 phase 3 wire and 3 phase 4 wire configurations. This is suitable to be mounted on single as well as double pole system.
CTVT combined Metering unit can be offered suitable for the following system.
• Three phase, three wire system with one three phase VT (with HV Neutral unearthed) and two CT's per unit of required creepage.
• Three phase, four wire system with one three phase VT (with HV Neutral unearthed) and Three CT's per unit of required creepage.
These are combination of Current & Potential Transformers units used for 3 Phase HT Metering purposes in Indoor or Outdoor applications, with accuracy up to 0.2S class.
• Used for HT Metering
• Voltage Class: 11KV / 22KV / 33KV class
• Oil Filled Outdoor or indoor type
• Manufacturing as per IS & IEC standards.
• Primary Current, Accuracy Class, Burden and Number of Secondary Cores / Windings as Specified.
Made up of the finest grade material and cutting-edge technology, our products have seamless quality.
We are one of the leading manufacturer of RVT of any class, ratio and burden. Our RVT are quality product as per IS / IEC. We can manufacture RVT of all types up to 33 KV voltage class as per customer requirement on most competitive prices. Residual voltage transformer is used to detect unbalanced voltage in three phase system & to supply voltage to directional earth fault relay. For directional earth - fault relay. It is necessary that the voltage applied to the voltage coil of the relay corresponds in phase to that of the current in current coil such voltage will be the residual voltage of the system & will be the phasor sum of the three line - to - earth voltages. Residual voltage can be achieved by connecting secondary of three single phase V.T. Connected in three different phases, in open delta fashion. It is, however, economical to use three phase V.T. Instead of three Nos. Single phase R.V.T. Suitable up to 33 KV system voltage. In normal three phase three limb V.T.
For use in outdoor installations from 33KV class. Main insulation is provided by world class insulating paper, EHV Grade Oil and good MS Metal Tanks are used along with type tested porcelain. The process control is very stringent to give the customer a trustworthy product with long life.
• Hermetically Sealed Oil Filled Outdoor Type
• Three Phase type up to 33KV Class, Voltage Class: 11KV / 22KV / 33KV
• Manufacturing as per IS & IEC standards.
• Secondary Voltage: 110V / v3 or 110V
• Accuracy Class (upto 0.2), Burden, RVF and Number of Secondary Windings as Specified.
• Single Phase type from 11KV to 145KV
Copper enameled wire is used for winding. Primary is wound with multilayer and graded insulation. Secondary is separately wound and inserted in the primary winding as per the requirement. Winding and tapping of PT is done in dust-free atmosphere. CRGO silicon steel is used for building up electromagnetic core.
Shell type construction is used to minimize leakage reactance. Bottom tank and oil expansion chamber are made of MS sheet. Brown/white glazed porcelain bushing with different shed profiles to suit different pollution condition is used. These bushings are hollow cylindrical type conforming to IEC 815/IS 5621. High quality electrical grade Kraft paper and crepe paper is used for insulating primary and secondary of PT.
For use in outdoor installation of 33 KV class. Main insulation is provided by world class insulating paper, EHV Grade Oil and good MS Metal Tanks are used along with type tested porcelain. Hermetically Sealed Oil Filled Outdoor Type.
• Single Phase Live or Dead Tank Type
• Voltage Class: 11KV
• Manufacturing as per IS & IEC standards.
• Secondary Current: 1A or 5A
• Primary Current, Accuracy Class (upto 0.5S), Burden, Short Time Current and Number of Secondary Cores as Specified.
Agarwal Industries manufactures current transformers (CT) in both Live Tank and Dead Tank design types. CT can be designed for Single or Multi ratio. The ratio selection can be achieved by providing two or four sections or primary for series/parallel connection, the current ratio shall be in proportion of 1:2:4. The advantage of this type of ratio is that output from each secondary remains constant for any selected ratio.
High permeability CRGO silicon steel is used as core material. Torroidal cores from continuous strips are made at our works and annealed in controlled atmosphere to achieve best quality secondary cores. Secondary winding is done automatically and distributed equally on the periphery of the core to minimize leakage reactance. Primary winding is of braided electrolytic copper conductors with double cotton covering. Varnished fiber glass sleeve is provided as an additional insulation on this conductor. High quality crepe insulating paper is used to build up main insulation of the CT.Glazed porcelain bushing with different shade profiles to suit different pollution conditions are used. These bushings are hollow cylindrical type conforming to bushings IEC 815/15 5621. Top tank (which also acts as oil expansion chamber) of the CT having current less than 1200 Amperes are made of MS sheet.
Agarwal Industries manufactures Outdoor Oil cooled CTPT combined Metering unit upto 33KV for customer requirements as per IS 2705/1992 & IS 31546/1992, IS 60044(1) & IS 60044(2), and IEC 61869 (1) & IEC 61689(2). Agarwal Industries undertake Design, Manufacture and Supply of Instrument Transformers comprising of Current Transformers & Voltage / Potential Transformers with a notion right from LT class upto 33KV Class, an indigenous venture whose Quality matches upto international standards and meeting the stringent tropical service requirements. 33KV CTPT Combined Metering Unit is an oil cooled system. This system can be made in 3 phase 3 wire and 3 phase 4 wire configurations. This is suitable to be mounted on single as well as double pole system.
CTVT combined Metering unit can be offered suitable for the following system.
• Three phase, Three wire system with one three phase VT (with HV Neutral unearthed) and two CT's per unit of required creepage.
• Three phase, Four wire system with one three phase VT (with HV Neutral unearthed) and Three CT's per unit of required creepage.
These are combination of Current & Potential Transformers units used for 3 Phase HT Metering purposes in Indoor or Outdoor applications, with accuracy upto 0.5S class.
• Used for HT Metering
• Voltage Class: 11KV / 22KV / 33KV class
• Oil Filled Outdoor or indoor type
• Manufacturing as per IS & IEC standards.
• Primary Current, Accuracy Class, Burden and Number of Secondary Cores / Windings as Specified.
Made up of the finest grade material and cutting-edge technology, our products have seamless quality. We are one of the leading manufacturer of RVT of any class, ratio and burden. Our RVT are quality product as per IS / IEC. We can manufacture RVT of all types up to 33 KV voltage class as per customer requirement on most competitive prices. Residual voltage transformer is used to detect unbalanced voltage in three phase system & to supply voltage to directional earth fault relay. For directional earth - fault relay. It is necessary that the voltage applied to the voltage coil of the relay corresponds in phase to that of the current in current coil such voltage will be the residual voltage of the system & will be the phasor sum of the three line - to - earth voltages. Residual voltage can be achieved by connecting secondary of three single phase V.T. Connected in three different phases, in open delta fashion. It is, however, economical to use three phase V.T. Instead of three Nos. Single phase R.V.T. Suitable up to 33 KV system voltage. In normal three phase three limb V.T.