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Revision Notes Change notes Date B Revision 2006-09-25 3 New template. Collaboration with Vattenfall removed Primary current 1500 A introduced Thermal short time current 31,5 ka removed Min. hole diameter of 180 mm introduced 2013-02-25 3/17
Content 1 GENERAL... 6 1.1 Applicable standards... 6 1.2 Ambient temperature... 6 2 RATING... 7 2.1 Rated insulation level... 7 2.2 Rated frequency... 7 2.3 Rated primary current... 7 2.4 Rated secondary current... 7 2.5 Continuous load current... 7 2.6 Thermal short time current... 7 2.7 Cores and windings... 8 2.7.1 General... 8 2.7.2 Measuring cores... 8 2.7.3 Relay cores... 8 2.7.4 Overcurrent figure... 9 3 Design... 10 3.1 General... 10 3.1.1 Attachment... 10 3.1.2 Corrosion... 10 3.1.3 Casing... 10 3.2 Hole diameter... 10 3.3 Secondary terminals... 10 3.3.1 Terminal box for secondary terminals... 10 3.3.2 Kontaktdetaljer Contact components... 10 3.3.3 Clamp design... 10 3.4 Marking... 11 3.4.1 3.4.1. Rating plates... 11 3.4.2 Primary marking... 11 3.4.3 Secondary marking... 11 3.4.4 Plate design... 11 4/17
4 TESTING... 11 4.1 Type tests... 11 4.1.1 Temperature-rise test... 11 4.1.2 No-load curve and winding resistances... 11 4.2 Routine test... 12 4.2.1 Power-frequency tests on secondary winding... 12 4.3 Test certificates... 12 4.3.1 Type-test certificates... 12 4.3.2 Routine-test certificates... 12 5 DOCUMENTATION... 12 5.1 General... 12 5.2 Tender documentation... 12 5.3 Documentation together with apparatus delivery... 13 6 DELIVERY... 14 7 Appendix... 15 7.1 Appendix 1 Component Data List... 15 5/17
1 GENERAL 1.1 Applicable standards Applicable Swedish Standards are valid. When there is no Swedish Standard, European Standard (EN) and IEC Publication shall apply. The latest edition shall apply. Where current transformers offered do not in every way fulfil the stipulated standards and the additions of the guidelines, deviations shall be specified. Applicable standards and guidelines: SS-EN 60044-1 SS-EN 60044-6 SS-EN 60529 SS-EN ISO 1461 IEC 59 IEC 60815 Instrument transformers Part 1: Current transformers Instrument transformers Part 6: Requirements for protective current transformers for transient perfor mance Degrees of protection provided by enclosures (IP code). Hot dip galvanized coatings on fabricated iron and steel articles IEC standard current ratings Guide for the selection of insulators in respect of polluted conditions. 1.2 Ambient temperature The following temperature limits shall apply for different applications: Application Lower limit Upper limit Degrees Celsius For indoor installation - 25 + 40 For outdoor installation - 50 + 40 6/17
2 RATING 2.1 Rated insulation level The current transformers shall fulfil requirements in SS-EN-60044-1. 2.2 Rated frequency The rated frequency shall be 50 Hz. 2.3 Rated primary current Current transformers shall have a primary rated current according to one of the values in the following table: For measuring and protection relays 150 A 300 A 500 A 1000 A 1500 A Higher rated values can be specified at greater currents if the alternative with more cables in parallel cannot be chosen. 2.4 Rated secondary current Current transformers shall normally have a rated secondary current of 1 A, or for measuring purpose 5 A at smaller substations below 52 kv. In some cases 2 A, in line with old standard, may be specified. 2.5 Continuous load current The rated continuous thermal current for the current transformer shall be the same as the rated primary current. 2.6 Thermal short time current Current transformers shall be designed to withstand thermal short-time current during 1 s of minimum 40 ka (r.m.s.). 7/17
2.7 Cores and windings 2.7.1 General Current transformers shall be designed with one core and one secondary winding. 2.7.2 Measuring cores Measuring cores shall at least fulfil the following demands ( Minimum hole diameter is the value required if the current transformer shall be able to be used at all normally applied voltages): Rated primary current A Minimum hole diameter mm Rated burden class 0.2 S VA Rated overcurrent figure 150 80 7,5 <10 300 80 7,5 <10 500 120 10 <10 1000 140 10 <10 1500 180 10 <10 The accuracy class requirements shall be fulfilled from 1 VA up to 100 % of the rated burden. If difficulties arise in obtaining the given overcurrent figure, in certain cases after special agreement, a higher value can be accepted. 2.7.3 Relay cores Relay cores shall fulfil the following demands ( Minimum hole diameter is the value required if the current transformer shall be able to be used at all normally applied voltages): 8/17
Rated primary current A Minimum hole diameter mm Rated burden according to Class 10P10 VA Class 1.0 VA 150 150 * - 10 300 80 30 30 500 120 30 30 1000 140 30 30 1500 180 30 30 * Relay cores with rated primary current 150 A are intended for the summation current of three-phase cables, or alternatively three single-phase cables. The no-load impedance shall be measured on the secondary winding at voltage 0.1 V. 2.7.4 Overcurrent figure The resistance of the secondary winding shall be measured and the constant RCT shall be stated at 75 O C winding temperature. In addition to IEC 60044-1, clause 11.6 and 12.5.b, the overcurrent figure, n, shall be calculated from real (measured) values according to: n = FS = I exc / I sn and n = ALF = I exc / I sn (ALF = accuracy limiting factor) Concerning the magnitude of overcurrent figures, see clause 2.7.2 and 2.7.3 (denomination of class). 9/17
3 Design 3.1 General 3.1.1 Attachment Current transformers shall be provided with attachment feet, designed for fixing in arbitrary position. Holes for bolts-through can in certain cases be accepted after special agreement. 3.1.2 Corrosion All parts exposed to corrosion shall be made of non-corrosive material. 3.1.3 Casing The current transformers shall be made of non-hygroscopic material, and shall be hermetically sealed. Internal insulation shall be satisfactory and permanently protected against moisture. Casing and associated gaskets shall be resistant to direct solar radiation, heat, air, oil, and water. They shall also be designed with a safe mechanical strength. The composition of materials shall be specified as well as combustion decomposition products (gases) that may occur at a failure. 3.2 Hole diameter See clause 2.7.2 and 2.7.3 3.3 Secondary terminals 3.3.1 Terminal box for secondary terminals The terminal box shall be spatial enough to allow the connection of necessary connecting leads to be carried out comfortably. The terminal box shall be semi-enclosed and spray-tight (Protection class minimum IP 54 according to SS-EN 60529) and be provided with rain-protected, net-covered breather holes. Box-cover gaskets shall be resistant towards solar radiation, air, oil and water. 3.3.2 Kontaktdetaljer Contact components All contact components, even screws, shall be made of non-corrosive metal. 3.3.3 Clamp design Terminal clamps and earthing clamps shall be designed for connection of up to 6 mm2 stranded conductors, and be such that conductors can be connected without cable lugs and without sustaining damage. 10/17
3.4 Marking 3.4.1 3.4.1. Rating plates The current transformer rating plate shall include data in accordance with SS-EN 60044-1. Total weight and serial number shall also be specified. 3.4.2 Primary marking Current transformers shall have a durable marking on the housing. This marking should not be done on the sides. 3.4.3 Secondary marking The secondary terminals shall have durable marking corresponding to the primary marking. 3.4.4 Plate design The rating plates shall be made of anodised aluminium sheet or equivalent noncorrosive material. Deviations from this may only be done after approval by the purchaser. 4 TESTING If the test laboratory of the supplier follows ISO 17025, the laboratory is considered to fulfil the accuracy demands. If not so, the supplier must provide documentation of the testing procedure and the tracability of the standards. 4.1 Type tests 4.1.1 Temperature-rise test Temperature-rise test shall be carried out at rated current. 4.1.2 No-load curve and winding resistances A complete no-load curve shall be plotted in order to determine constant n (See Clause 2.7.4) and to check the no-load impedance in accordance with Clause 2.7.3 The secondary winding resistance shall be measured and constant RCT (See Clause 2.7.4) shall be specified at 75 OC winding temperature. The instrument transformer security factor and accuracy limit factors shall be calculated and given according to Clause 2.7.4. 11/17
4.2 Routine test 4.2.1 Power-frequency tests on secondary winding During this test the primary conductor (the cable) shall be replaced by an earthed metal structure that fills out the cable hole. The secondary terminal box shall be attached and outer metal parts of the transformer shall be connected to earth during test. 4.3 Test certificates 4.3.1 Type-test certificates Type-test certificates shall without request be sent to the purchaser as soon as possible. If production has been moved to another plant, material has been changed, or if typetest certificate is more than five years old, certificate cannot be accepted without special agreement. 4.3.2 Routine-test certificates The routine test certificates shall include, in addition to the routine-test results and when applicable, the following information: > The date and number of the type-test certificate. > Current-transformer data. > Constants n and RCT for all cores. > Purchaser s reference number. > Serial number. 5 DOCUMENTATION 5.1 General Instructions, dimension drawings and diagrams, handed over at delivery of the current transformer, shall be in Swedish. 5.2 Tender documentation With the tender the following documents shall be provided: > List of data, dimension drawings, electrical circuit and schematic diagrams, instructions for erection, operation and maintenance, type test certificates and also other documents needed for the technical evaluation. 12/17
> Bases for evaluation of the need and costs for maintenance, such as: The interval for condition control and other measures of maintenance and the time necessary for these works. Necessary spares, special tools and accessories and the costs for these. > Environmental information as below (see also TR 13-01): The interval for condition control and other measures of maintenance and the time necessary for these works. Information about the main content of the equipment (type of material in percentage of weight) Information about the content of dangerous substances (for example heavy metals, carcinogenic compounds and compounds hard to biodegrade, xenobiotic substances) 5.3 Documentation together with apparatus delivery In connection with the apparatus delivery the following documents shall be submitted electronically and in one paper copy, if not otherwise agreed: A list (current transformer chart) including: > Purchasing and order number > Manufacturer > Type > Serial number > Rated data > Type test certificates Verification (title and number) of the following documents that shall be delivered together with the list: > General assembly drawings and drawing lists > Instructions for transport, storing, erection, service, testing, condition monitoring and adjustment > List of other chemical products > List of products and protective information for all listed chemical products 13/17
> Final dimension drawings > Final circuit diagrams > Routine test certificates > Filled in Components data list according to appendix 1. A complete compilation file shall be handled over to the buyer, latest when all ordered current transformers are delivered. It shall include test certificates for all current transformers of the delivery in accordance with paragraph 4.3.2. 6 DELIVERY The delivery is not considered finished until complete test certificates and required documentation have been submitted to the purchaser and have been approved. 14/17
7 Appendix 7.1 Appendix 1 Component Data List Apparatdatalista för strömtransformatorer Svenska Kraftnät Beskrivning Värde Enhet Not Allmänt Station * Ifylls av ställverksbyggaren EX Hagby, CT 65 Objekt id/littera * Ifylls av ställverksbyggaren EX CL6 S5-IT Beskrivning * Strömtransformator Lägsta omgivningstemp oc Ex -50 Inköpsnummer * Leverantörens ordernummer * Tillverkare * Typbeteckning * Tillverkningsnummer * nummer Levererad * ååmm Utförandeform * Fristående/genomföring (trafo, reaktor)/kabelströmsgenomfö ring Huvudkonstruktion * Utomhus/inomhus Kontruktionsspänning kv EX 420kV Märkström A Märkkorttidsström, 1s ka Stötström, dynamisk ka Primär isolationsnivå till jord - kort kv EX 950 Primär isolationsnivå till jord - lång kv EX 1050 Primär isolationsnivå till jord - 50Hz 1 kv EX 395 Sekundär korttids växelsp. lindn-lindn, kv EX 4 Spolbarhet * Ja/Nej/Begränsad Minsta fasavstånd m Vikt per tre faser kg 15/17
Pris per tre faser SEK Norm, Riktlinje * EX TR1-04, revb Standard * SS-EN 60044-1, SS-EN 60044-6 Ombyggnadsdatum * ååmm Senaste drifttagningsdatum * ååmm Omkopplingsbar (normalt sekundärt) EX sekundärt Märkomsättning 1-Primär märkström A EX 2000 Märkomsättning 2-Primär märkström A EX 4000 Inkopplad omsättning A EX 2000 Sammanställningsritning * Ritningsnummer Måttskiss * Ritningsnummer Montage och skötselanvisning * Ritningsnummer Kretsschema * Ritningsnummer Provningsnormal * Ritningsnummer Isolermedium olja/gas/torr, spec nr Mängd isolermedium kg Kapacitivt uttag * Ja/Nej Max statisk horisontell anslutning- N EX 3000 Max statisk vertikal anslutningskraft N EX 3000 Apparatuttag, storlek EX 9-125 (platta), 60 (tapp) Kapslingsklass anslutningslåda * IP54/55 Typ av isolator * porslin/komposit Krypsträcka isolator mm Ritningsnr pol * Ritningsnr isolator * nummer Kärnor kärna 1 * Märkbörda kärna 1 VA Ex 15 Utökad termiskt mätområde * Ex 150% Märkomsättning 1-Sekundär märk- A Ex 1 Klass kärna 1 * EX 0,2 S Överströmstal Fs kärna 1 * EX 10 Konstanten RCT för kärna 1 ohm kärna 2 * 16/17
Märkbörda kärna 2 VA Ex 30 Utökad termiskt mätområde omsätt- * Ex 150% Märkomsättning 1-Sekundär märk- A Ex 1 Klass kärna 2 * EX 5P30 Överströmstal ALF kärna 2 * EX 10 Konstanten RCT för kärna 2 ohm kärna 3 * Märkbörda kärna 3 VA Ex 30 Märkomsättning 1-Sekundär märk- A Ex 1 Klass kärna 3 * EX 5P30 Överströmstal ALF kärna 3 * EX 10 Konstanten RCT för kärna 3 ohm kärna 4 * Märkbörda kärna 4 VA Ex 30 Märkomsättning 1-Sekundär märk- A Ex 1 Klass kärna 4 * EX 5P30 Överströmstal ALF kärna 4 * EX 10 Konstanten RCT för kärna 4 ohm kärna 5 * Märkbörda kärna 5 VA Ex 30 Märkomsättning 1-Sekundär märk- A Ex 1 Klass kärna 5 * EX 5P30 Överströmstal ALF kärna 5 * EX 10 Konstanten RCT för kärna 5 ohm 17/17