Transformer Bushings Type COT 125 COT 1050 - …

1 Transformer BushingsType COT 125 .. COT 105024 kV to 245 kVup to 3150 AIEC 137 experience in bushing manufacture for more than 80 years capacitive fine graded oil-paper insulation with long term experiencecomputer optimized electrical field distribution proven high electrical withstand against transient or impulse stressesexcellent long term stabilitydue to extremely low partial discharge and power loss factoroil immersed part covered by epoxy resin tube providing high impact resistanceelectrode embedded in the epoxy resin tube avoids external shielding reduces distance to groundporcelain cemented into

2 Flange provides higher mechanical strength than level II of IEC 137 Features2 available with porcelain orcomposite insulator on airsideinclination in service up to 40 fr om vertical; for COT 125 and COT 170even horizontal operationpossiblehorizontal transport for alltypes possibletanand PD-values more than twice as good as requested by IEC 137current rating can easily be increased up to 1250A by exchanging the cable bolt with a removable split conductor on existing bushingCertified ISO 9001 Transformer Bushings Type COT 1050 and COT 125If you need any Transformer bushing proven in operationconditions around the world, Trench has it !

3 To preserve ourenvironment the free oil volume in COT- Bushings is minimized(see table page 14) 2 DesignCut viewgeneral design861137110811263457 TerminalAssemblyHeadOil fillingInsulatorTerminal (Al or Cu) forconnection of overhead lines or bus bars and arcing horns. Our design provides a maintenance free termination and ensuresthat the connection will not become loose in whole bushing is tightened together by the central tube or head with oilexpansion chamber and oil level indicator. The chamber is hermetically sealed against atmosphere. COT Bushings are filled with dryed, degassed insulating mineral Insulator made of high grade electrotechnical porcelain according to IEC 815.

4 The insulator is connected to the mounting flange using Portland cement and sealed with o-ring gasket. Instead of porcelain a composite insulator is also available. Active partFlangeCT-PocketOil side endEnd-shieldingThe active part is made of oil-impregnated wide band paper with layers of aluminium foil to control the electrical field radially and axially. Depending on the current rating, the paper and foil are wound on either a central tube or a solid flange with integrated test tap made of corrosion free aluminium alloy, machined to ensure an excellent seal between the bushing and the Transformer .

5 If current transformers are required on the bushing, the ground sleeve can be extended. The insulator on the oil side is made of an epoxy resin tube. Itis designed to stay installed during the in-tank dryingprocess of the Transformer and can withstand temperatures up to 130 voltages starting with 52 kV a special aluminium electrode is cast into the end of the epoxy resin tube. This end shielding controls the electrical field 1101919245 strength in this area to of our bushing assembly stationsOne of our bushing assembly stationsOne of our bushing assembly stationsTest tapProduct RangeProduct RangeProduct RangeBushings forBushings forBushings for Power transformers Power transformers Power transformers Power Transformersup to 765 kV, 3150 Aup to 765 kV, 3150 Aup to 765 kV, 3150 Aup to 765 kV, 3150 A(>245 kV see separate(>245 kV see separate(>245 kV see separate(>245 kV see separatebrochure E )brochure E )))

6 High Current Application High Current Application High Current Applicationup to 36 kV, 25000 Aup to 36 kV, 25000 Aup to 36 kV, 25000 Aup to 36 kV, 25000 A Transformer to SF6 Transformer to SF6connection up to 550 kVconnection up to 550 kVconnection up to 550 kVconnection up to 550 kV Gas-Insulated Switchgear Gas-Insulated Switchgear(GIS) up to 800 kV, 6000 A(GIS) up to 800 kV, 6000 A(GIS) up to 800 kV, 6000 A Generators Generatorsup to 36 kV, 45000 Aup to 36 kV, 45000 Aup to 36 kV, 45000 A Railways Railways Buildings Buildingsup to 244 kV, 3000 Aup to 244 kV, 3000 Aup to 244 kV, 3000 Aup to 244 kV, 3000 ABushings according to all mainBushings according to all mainBushings according to all mainBushings according to all mainstandards as:standards as.

7 IECANSI (see separate brochure ANSI (see separate brochure ANSI (see separate brochure ANSI (see separate brochure ANSI (see separate brochure E )BSUTEB ushings according toBushings according toBushings according toBushings according tocustomer s special specificationcustomer s special specificationcustomer s special specificationcustomer s special specification4 QualityQualityQualityQualityQualityQuali tyQualityAt Trench quality is a way of At Trench quality is a way of At Trench quality is a way of At Trench quality is a way of At Trench quality is a way of At Trench quality is a way of At Trench quality is a way of life.))))

8 Trench quality assurance life. Trench quality assurance life. Trench quality assurance life. Trench quality assurance life. Trench quality assurance life. Trench quality assurance life. Trench quality assurance complies with the mostcomplies with the mostcomplies with the mostcomplies with the mostcomplies with the mostcomplies with the mostcomplies with the moststringent standard of stringent standard of stringent standard of stringent standard of stringent standard of stringent standard of stringent standard of ISO 9001. Certified by AFAQISO 9001. Certified by AFAQISO 9001. Certified by AFAQISO 9001.

9 Certified by AFAQISO 9001. Certified by AFAQISO 9001. Certified by AFAQISO 9001. Certified by AFAQ since frequency voltage withstand test including PD-measurement Epoxy resin insulator with embedded voltageUr Rated phase to earth voltageU /r 125 COT 170 COT 250 COT 325 COT 45024365272,51001421304258507095140185 Impulsevoltage1,2/50sRatedcurrentIr Connection totransformer125170250325450800100012501 6002500315080010001250160025003150800100 0125016002500315080010001250160025003150 80010001250160025003150cablecablecableca blecablecable)1cable)1cable)1cable)1cabl e) ) ) )2 rem. Cu-cond.

10 2 rem. Cu-cond.)2fixed :crosssectionCu-cond.:diameter--35400400 ---35400400---35400400-40040035---400400 35---ADArcingdistance(min.)Standardcreep agedistance(min.) : 0, 300, COT 125 .. 450 Cantilevertest load(min.)200020002000200020003150200020 0020002000200031502000200020002000200020 0020002000200020002000200031503150315040 0040004000N01020304050607080910111213 Comments related to columns :02,04,05:Rated and test voltagesacc. to IEC 13707: ) Class F insulated ) Removable solid rod copper conductor connection system see page : Extension for current extensions on for lead out ArrangementEmbedded ElectrodeExternal ShieldingThese Bushings are equipped on the lower end with acone shaped epoxy resin tube and an embedded electrode.