Find the most up-to-date version of IEC at Engineering INTERNATIONAL STANDARD IEC Fifth edition Insulated bushings for alternating voltages above 1 V This English-language version is . Insulated bushings for alternating voltages above 1 V. Reference number. IEC (E). INTERNATIONAL. STANDARD. IEC. Fifth edition.
|Published (Last):||25 February 2012|
|PDF File Size:||18.59 Mb|
|ePub File Size:||5.61 Mb|
|Price:||Free* [*Free Regsitration Required]|
Limiting values for temperature rise and dielectric dissipation factor have therefore been introduced.
INTERNATIONAL STANDARD IEC 60137
The end for immersion shall be mounted on a tank as for normal operation at ambient temperature. NOTE Capacitance and dielectric dissipation factor measurements made on site may differ from factory values given on the nameplate. Alternative methods of leakage detection may be used by agreement between purchaser and supplier. The angle of mounting of the bushing for the wet power-frequency voltage withstand test and wet switching impulse voltage withstand test may be the subject of special agreement between purchaser and supplier.
In the case of transformer bushings with the conductor drawn into the central tube, the supplier shall indicate the value of the cross-section, and the material of the conductor which correspond to I r in accordance with 4.
Tests — Test Q: Choice of test criteria IEC For transformer bushings, t th shall be 2 s, unless otherwise stated, with reference to IEC The time intervals between consecutive applications of the voltage shall be sufficient to avoid effects from the previous applications of voltage. Please contact the Customer Service Centre see below for further information. The test shall be a type test only in the case of bushings with gaskets of which the final placing is not carried out by the supplier, for example the top cap gasket of draw-through conductor transformer bushings.
Information relating to this publication, including its validity, is available in the IEC Catalogue of publications see below in addition to new editions, amendments and corrigenda.
If artificial pollution tests are required, they shall be performed in accordance with IEC It is recommended to make reference measurements at installation.
To avoid destruction of the insulation in the case of bushings with the conductor embedded in the insulating material, the temperature of the hottest spot may, by agreement between purchaser and supplier, be determined as follows: The high-voltage connection shall extend in line with the axis of the bushing to a point at least 0,4 L above the top of the bushing.
In such a case, the operating current and cross-section should conform with the requirements of 8. For bushings with I r equal to or greater than 4 A, I th shall always be kA. Gas-insulated bushings shall be at ambient temperature at the beginning of the test. The insulator shall be completely filled with an appropriate medium.
For gas-insulated bushings according to 3. It is not necessary to adjust the radial thickness of insulation or the clearance of the immersed end.
In the case of other insulating materials, the temperature limits shall be stated by the supplier.
A bushing is normally tested in an arrangement having sufficient clearance to surrounding earthed parts to avoid direct flashover to them through the ambient air or the immersion medium. For bushings with internal bellows, the pressure shall be stated by the supplier. Liquid-containing bushings shall iiec empty and shall have an opening for free gas circulation within the envelope.
IEC | IEC Webstore
The load shall be applied perpendicular to the axis of the bushing at the mid-point of the terminal for 60 s. For capacitance graded bushings it is assumed that a puncture has occurred if the capacitance measured after the test rises above the capacitance previously measured by about the amount attributable to the capacitance of one layer. In order to ensure that the external withstand voltages of the bushing are sufficient at altitudes exceeding 1 m, the arcing distance normally required shall be increased by a suitable 06137.
The measurement shall not be made at a voltage exceeding the dry power-frequency withstand voltage. Power transformers and reactors IEC The tank shall be completely filled with an appropriate liquid. The sealing assembly method shall be agreed upon between purchaser and supplier.
The gas shall be maintained at a temperature agreed upon between purchaser and supplier. The time intervals between consecutive applications of the voltage shall be sufficient 6017 avoid effects from the previous application of voltage. Enter the exact number of the standard: Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
The bushing has reached thermal stability when its dielectric dissipation factor shows iecc appreciable rising tendency, with respect to the ambient temperature, for a period of 5 h.
Q2 Please tell us in what capacity ies you bought the standard tick all that apply. Repetition of a type test is only mandatory when specified in a particular contract.
The standard values of insulation level of a bushing having U m equal to or greater than kV shall be chosen from values given in Table 8.