IEC 60172 pdf download

IEC 60172 pdf download.Test procedure for the determination of the temperature index of enamelled and tape wrapped winding wires
1 Scope
This International Standard specifies, in accordance with the provisions of IEC 6021 6-1 , a method for evaluating the temperature index of enamelled wire, varnished or unvarnished with an impregnating agent, and of tape wrapped round and rectangular wire, in air at atmospheric pressure by periodically monitoring changes in response to AC proof voltage tests. This procedure does not apply to fibre-insulated wire or wire covered with tapes containing inorganic fibres. NOTE The data obtained according to this test procedure provide the designer and development engineer with information for the selection of winding wire for further evaluation of insulation systems and equipment tests.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 6021 6-1 , Electrical insulating materials – Thermal endurance properties – Part 1: Ageing procedures and evaluation of test results IEC 6021 6-3, Electrical insulating materials – Thermal endurance properties – Part 3: Instructions for calculating thermal endurance characteristics
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply. 3.1 temperature index TI numerical value of the Celsius temperature expressed in degrees Celsius characterizing the thermal capability of an insulating material or an insulation system Note 1 to entry: In case of insulating materials, the temperature index is derived from the thermal endurance relationship at a given time, normally 20 000 hours. It may be used as basis for determination of the material’s temperature class. Note 2 to entry: In case of insulation systems, the temperature index may be derived from known service experience or from a known comparative functional evaluation of an evaluated and established reference insulation system as basis. [SOURCE: IEC 60050-21 2:201 0, 21 2-1 2-1 1 ] 3.2 specimen failure time n u m ber of hours at the exposure temperature that have elapsed at the time a specimen fails the proof test Care shall be taken that the centre section shows a close contact between the two pieces. After tying, further bending of the ends shall be avoided. Pre-annealing of the specimen prior to testing or impregnating will remove stress and craze marks and therefore may be desirable with certain material. e) Prior to testing the specimen shall be proof-tested at 1 000 V a.c. 5.2 Varnish impregnation Experience has shown that insulated wire according to IEC 6031 7 and impregnating agents according to IEC 60455-3-5 or IEC 60464-3-2 can affect one another during the thermal ageing process. NOTE 1 Testing varnished specimens will allow for evaluation of the compatibility of the wire insulation with an impregnating agent. Thus the temperature indices of different combinations can be compared. Interaction between wire insulation and such agent may increase or decrease the relative thermal life of this combination compared with the life of the wire tested without impregnation. Therefore, with impregnated specimens, this test procedure may give an indication of the thermal endurance of a combination of wire insulation and impregnating agent. If such impregnation is required, the following procedure shall be applied: With the specimen in the vertical position, it shall be immersed in the impregnating agent for (60 ± 1 0) s (see note). It shall be removed slowly and uniformly at a rate of about 1 mm/s. It shall be drained horizontally for 1 0 min to 1 5 min and cured horizontally according to the manufacturer’s recommendation or to an agreed schedule. If more than one treatment is to be given, immerse, drain and cure the specimen vertically reversing the specimen for each subsequent treatment.