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.
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In particular, in the case of bushings intended for use on gasinsulated switchgear and transformers, tests 6137 be required with simulation of adjacent metal parts on the GIS or transformer side. NOTE 2 A bushing which contains solid insulating materials other than the envelope containing the gas e.
On-line information is also available on recently issued publications, withdrawn and replaced publications, as well as corrigenda.
It is permissible, after changing polarity, to apply some impulses of minor amplitude before the application of the test impulses. Any other angle of mounting shall be subject to agreement between purchaser and supplier.
Temperature limits and temperature rise The temperature limits of metal parts in contact with insulating material under normal operating conditions, are as follows: One method is to wrap iex resistive insulated wire around a conductor dummy and to feed it by 6037 suitable supply.
Choice of test criteria IEC In the case of other insulating lec, the temperature limits shall be stated by the supplier. This standard is applicable to bushings, as defined in Clause 3, intended for use in electrical apparatus, machinery, transformers, switchgear and installations for three-phase alternating current systems, having highest voltage for equipment above 1 V and power frequencies of 15 Hz up to and including 60 Hz.
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Definitions, principles and rules IEC The gas shall be maintained at a temperature agreed upon between purchaser and supplier. NOTE 2 By agreement between purchaser and supplier, other temperature ranges may be adopted. The concentration of gas in the air inside the envelope shall be measured twice at an interval equal to or greater than 2 h.
For bushings of highest voltages for equipment equal to or less than 52 kV, made of ceramic, glass or inorganic materials, resin or composite insulation, see Clause For bushing terminals and connections, the temperature rises are also given in Table 2. NOTE 2 The bushing may be of the types as prescribed in 3. In the case of bushings for gas-insulated switchgear, special test requirements for chopped lightning test may be agreed upon between purchaser and supplier to cover the behaviour of the bushing concerning very fast transient voltage.
Liquid-filled and liquid-insulated bushings, according to 3.
If a tilted or horizontal bushing oec to be tested vertically, then an equivalent force should be added to achieve the bending moment at the flange, caused by the weight of the bushing in its operating position. The end for immersion shall be mounted 660137 a tank as for normal operation at ambient temperature.
For other bushings, tests to check dielectric, thermal and mechanical properties of bushings comprise the following tests. NOTE For gaskets in contact with metallic parts, special attention should be paid to the ability of the material to withstand the temperature rise. Table 10 — Applicability of type tests see 7.
For capacitance graded bushings it is assumed that a puncture has occurred ie the capacitance measured after the test raises above the capacitance previously measured by about the amount attributable to the capacitance of one layer.
The bushing shall be considered to have passed the test if there is no visual evidence of damage and if it has withstood a repetition of all routine tests without significant change from the previous results.
NOTE Capacitance and dielectric dissipation factor measurements made on site may differ from factory values given on the nameplate. 06137 IEC Figure 3 — Marking plate for bushings for highest voltage for equipment equal to or less than 52 kV made of ceramic, glass or inorganic materials, resin or combined insulation see Where there is no evidence of the above, 6017 test is considered satisfactory even though the fittings may have been stressed beyond their yield point.
The measurement shall not be made at a voltage exceeding the dry power-frequency withstand voltage. If the partial discharge at the end of the period is within limits, then the bushing shall be accepted.
INTERNATIONAL STANDARD IEC 60137
The time intervals between consecutive applications of the voltage shall be sufficient to avoid effects from the previous applications of voltage. Temperature rise IEC If, during the repetition of the test, no flashover or puncture occurs, the bushing shall be considered to have passed the test. 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 amount.
Gas-insulated and gas-impregnated bushings have become a mature technology, for use in gas insulated switchgear. For bushings operating in air-insulated ducting, locally high ambient air temperatures have a significant effect ieec their current rating.
The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields.
Normally, GIS and transformer bushings are tested in the vertical position, with the flange earthed or held near to earth potential. The supplier shall provide a detailed type test certificate at the request of the purchaser. Special consideration may be necessary for bushings, one or both ends of which are intended to be immersed in a gaseous medium.
The load shall be applied perpendicular to the axis of the bushing at the mid-point of the terminal for 60 s.