Current TransformersType IOSK Current Transformers and Combined Instrument Transformers (voltage and current transformer in one unit). This brochure will detail the features and characteristics of Trench Type IOSK Current Transformers. protection and control of the high voltage system. Current Transformers must convert high transmission line currents (up to 5000 A) to standardized low and ea- sily measurable values. which will be used for metering. Current Transformers Introduction Trench is a recognized world leader in the design and manufacture of high voltage equipment for application on electric utility and high energy industrial systems. As part of Trench's product scope. As such. Please refer to Trench brochure E210 for ad- ditional general information concer- ning high voltage Instrument Trans- formers. 1 Type IOSK Current Transformer 2 . the need for accurate and reliable current transformation is es- sential. Fig. Instru- ment Transformers include: Voltage (Potential) Transformers (both induc- tive and capacitive type). the company produces a diversified range of Instrument Transformers which are installed on 69-800 kV electrical systems. insulating system with high as a consequence of optimized • Primary reconnection available reliability design of flanges. 2 A or 5 A • short. TPY and TPZ and minimum oil volume period of time (other standards on request) • use of high quality mineral oil. resistant materials • Rated primary currents up tion • explosion resistant by: to 5000 A • excellent seismic performance . TPX. symmetrically arranged headcasting and the metallic low reactance bar-type primary bellows serving as pressure • Rated short circuit withstand conductor permits higher short release device up to 200 kA peak circuit currents and avoids large voltage drop across the primary • 1:1 A current ratio possible • Quality Assurance in winding • Successful field experience since accordance with ISO 9001 • excellent control of internal and the manufacture of the first external insulation stresses current instrument transformer through the use of a proprietary in 1924 finely graded bushing system • maintenance free during a long • hermetically sealed by stainless lifetime of more than 30 years steel metallic bellows • composite insulators available on • welded housing sealed without request screws • uniformly distributed secondary windings guarantee accurate transformation at both rated and high currents 3 .fine graded bushing their interconnection • Rated secondary current . • exclusive use of corrosion PCB free. porcelain and .Features • highly refined and processed • essentially unaffected by stray • Meet all IEC and ANSI metering oil/paper insulation system external magnetic fields and protection classes. including special core classes • Head type design of low weight • stable accuracy over a long TPS.weakpoint in the aluminium 1 A. biological decomposi. calibrated to the removable gland plate internal oil volume and extremes in ambient and operating temper- atures. the type IOSK is produced • Anti-corona rings with different size heads. highly reliable. ratings. Construction Standard Equipment Trench type IOSK Current Transfor. • Secondary terminal box with pansion bellows. • Stud type primary terminal have a direct bearing on the size • Primary or ground cable of the "head" or core housing for connector each Current Transformer. • Bellows position indicator oil/paper insulation system. number of cores. Each • Oil filling port porcelain housed. Customer specifications. • Gas Detection System (contact Trench for additional details) • Terminal box heater • Composite Insulators 4 . These CT's • Lifting lugs are designed and constructed with the well proven. hermetically sealed Current Transformer is • Oil drain valve equipped with stainless steel ex. such as Optional Equipment application (metering or protect- ion). • Aluminum flat pad primary mers are defined as "head type" terminal and ground terminal Current Transformers. Trench • Capacitance tap for measure- will recommend the optimum Fig. etc.2 IOSK 245 Current Transformers ment of voltage or tan delta of design based on each individual bushing customer specification. For this reason. 170 kV 245 .550 kV 11 3 3 11 2 2 10 1 1 10 14 14 12 15 13 12 15 13 4 4 6 5 8 5 7 7 9 8 6 9 1 Primary terminal 2 Metallic expansion bellows 3 Oil filling screw 4 Porcelain insulator 5 Secondary terminal box Without primary reconnection Primary reconnection 1:2 6 Secondary terminals 7 Oil drain valve 8 Grounding terminal 9 Gland plate 10 Lifting lugs 11 Bellows indicator 12 High voltage insulation 13 Secondary winding and cores Primary reconnection 1:2:4 Secondary reconnection 14 Primary winding 15 Transformer head Fig.3 (aluminum) Electrical and mechanical design details 5 . 72.5 . continuous Test voltage Impulse Switching Min. Oil/paper-insulated Current Transformers Electrical and Mechanical Data (1) Type Max. withstand impulse sparking creepage 1 min.5 140 325 – 700 1815 IOSK 123 123 230 550 – 1200 3815 IOSK 145 145 275 650 – 1200 3815 IOSK 170 170 325 750 – 1400 4495 IOSK 245 245 395 950 – 2200 6300 IOSK 245 245 460 1050 – 2200 6300 IOSK 300 300 460 1050 850 2200 6300 IOSK 362 362 570 1300 950 2650 9955 IOSK 420 420 630 1425 1050 3200 11550 1175 3800 1050 3200 IOSK 420 420 680 1550 1175 3800 11550 1300 4200 1175 3800 IOSK 550 550 680 1550 1175 3800 15125 1300 4200 Notes: (1) Other ratings available on request 6 . test voltage test voltage distance distance phase to phase dry/wet full wave 250/2500 µs 1.2/50 µs wet kV kV kV kV mm mm IOSK 72.5 72. Standard operating voltage 50/60 Hz. D Net weight Dimension Weight of approx. A Fig.B Fig. C Fig. oil h1 h2 Fig kg m mm kg A 160 1630 1215 31 A 200 2155 1715 35 B 380 2400 1825 70 A 200 2155 1715 35 B 380 2400 1825 70 A 220 2355 1915 44 B 390 2600 2025 79 B 470 3545 2970 79 C 700 3745 3080 158 B 470 3545 2970 79 C 700 3745 3080 158 B 470 3545 2970 79 C 700 3745 3080 158 C 900 4270 3600 184 D 1600 4570 3720 350 C 1000 4920 4150 245 C 1400 5515 4745 315 D 1700 5240 4270 411 C 1400 5515 4745 315 C 1600 5915 5145 380 D 2100 5840 4870 438 C 1400 5515 4745 315 D 2100 5990 5020 438 D 2300 6390 5420 505 7 . h2 h1 h2 h1 h2 h1 h2 h1 360 450 450 600 Fig. Phone: 905-426-2665 Trench® (UK) Limited Fax: 905-426-2671 South Drive Hebburn Trench® Limited Tyne & Wear Coil Product Division NE 31 1 UW 71 Maybrook Drive Phone: 44-191-483-4711 Scarborough..trenchgroup. Rue du Général Cassagnou No. Ontario Austria Canada M1P 3B5 Phone: 43-732-6793-0 Phone: 416-751-8570 Fax: 43-732-671341 Fax: 416-751-6952 Trench® Brasil Ltda Trench® Limited Via Expressa de Contagem. 2 Zhengliang Er.A.R. 2685 Power Line Carrier Division Contagem. MWB (Shanghai) Co. Cedex Peoples Republic of China France 200245 Phone: 33-3 89-70-2323 The Trench Group is your Phone: 86-21-54720088 Fax: 33-3 89-67-2663 Fax: 86-21-54723118 Trench® Germany GmbH partner of choice for electrical Trench® High Voltage Nürnberger Strasse 199 Products Ltd.. Shenyang D-96050 Bamberg No. Ontario Fax: 41-61-315-59-00 Canada L1S 2G7 of tomorrow. Shanghai St. China distribution solutions today.P.2006) Printed in Canada. Trench Facilities Trench® Austria GmbH Trench® Limited Paschinger Strasse 49 Instrument Transformer Division Postfach 13 390 Midwest Road A-4060 Linz-Leonding Scarborough. Road Germany power transmission and Jing Shen Xi San Street Phone: 49-951-1803-0 Dao Yi Economic Development Zone Fax: 49-951-1803-224 Shenyang 110136 P. Ontario Brazil Canada M1V 2P9 Phone: 55-31-3391-5959 Phone: 416-291-8544 Fax: 55-31-3391-1828 Fax: 416-291-5581 Trench® China Trench® France S. Jiancheng Road B. Phone: 86-24-89722688 Trench® Switzerland AG Fax: 86-24-89737200 Lehenmattstrasse 353 and for the development of CH-4028 Trench® Limited Basel Bushing Division Switzerland your new technology solutions 432 Monarch Avenue Phone: 41-61-315-51-11 Ajax. Louis. Minas Gerais 815 Middlefield Road. Unit 6A CEP 32370-485 Scarborough. 70 F-68 302 Minhang. Ontario Fax: 44-191-430-0633 Canada M1V 4B6 Phone: 416-298-8108 Fax: 416-298-2209 www.com E 217.11 Subject to change without notice (05. Ltd. 3658. 16. .