AS NZS 60137:2020 pdf download.Insulated bushings for alternating voltages above 1000 V (IEC 60137:2017 (ED.7.0) MOD).
6 Ordering information and markings
6.1 Enumeration of characteristics
6.1.1 General
When ordering, the purchaser shall furnish as much of the following information as necessary, as well as any additional information needed to determine clearly the required characteristics.
The minimum distance to earthed parts of the end of the bushing which is intended to be immersed in insulation liquid shall be provided by the supplier. In case distances are below the values for the standard arrangements indicated in suppliers documentation, the purchaser may also provide the necessary geometry to evaluate the particular set-up.
6.1.2 Application
Application, including type of apparatus for which the bushing is intended, and the corresponding IEC apparatus standard shall be given.
Attention shall be drawn to any features (including tests) of the completed apparatus which may affect the design of the bushing (see 7.3).
6.1.3 Classification of bushings
Classification according to 3.2 to 3.22.
6.1.4 Ratings
The ratings shall be as follows:
• highest voltage for equipment (‘m) (see 3.23);
• rated phase-to-earth voltage (see 3.24);
• standard insulation level (see 4.9) and the induced and/or applied test voltage level of the transformer (if applicable) (see 9.4);
• rated current (1r) (see 3.25);
• rated thermal short-time current (I(h) and rated duration (), if deviating from the values given in 4.3;
• rated dynamic current (1d)’ if deviating from the value given in 4.4;
• rated frequency (see 3.29):
• minimum withstand values of cantilever load in accordance with 4.5;
• maximum value of test tap capacitance, if lower value is required, in accordance with 4-10.
6.1.5 Operating conditions
The operating conditions shall be as follows:
• temporary overvoltages, if applicable (see 5.1):
• altitude, if exceeding 1 000 m (see 5.2) (relevant only to indoor and outdoor bushings according to 3.16 to 3.20):
• ambient air and immersion media temperature if deviating from normal values (see 5.3 and Table 4) (relevant to bushings according to 3.16 to 3.22):
• type of immersion medium (relevant only to partly or completely immersed bushings according to 3.19 to 3.22):
• minimum level of immersion medium (relevant only to partly or completely immersed bushings according to 3,19 to 3.22);
• maximum operating pressure of immersion media (relevant only to partly or completely immersed bushings according to 3.19 to 3.22);
• type of insulating gas (relevant only to gas-filled. gas-insulated and gas-impregnated bushings according to 3.5 to 3.7 when the gas of the equipment is in communication with that of the bushing);
• rated filling pressure of gas for insulation (see 3.30) (relevant only to gas-filled, gas- insulated and gas-impregnated bushings according to 3.5 to 3.7 when the gas of the equipment is in communication with that of the bushing);
• maximum internal operating gas pressure (see 3.31) (relevant only to gas-filled, gas- insulated and gas-impregnated bushings according to 3.5 to 3.7 when the gas of the equipment is in communication with that of the bushing);
• maximum external operating gas pressure (see 3.32) (relevant only to partly or completely gas-immersed bushings according to 3.19 to 3.21);
• angle of mounting if exceeding the standard values (see 4.6);
• minimum nominal specific creepage distance (see 4.7) (relevant only to the outdoor part of bushings according to 3.17, 3.18 and 3.20);
• unusual climatic conditions (extreme high and low temperatures, tropical humidity, severe contamination, high wind);
• seismic conditions, if qualification is required (see 5.4).
6.1.6 Design
The purchaser should provide requirements about the following, where applicable:
• for bushings supplied without a conductor: diameter, type (cable, solid or hollow stem), material and position of the conductor with which the bushing will be fitted in operation;
• particular dimensional requirements, If any:
• test tap or voltage tap if required (see 3.38 and 3.39);
• the length of earthed sleeve located next to the flange or other fixing device, if any:
• general information concerning the position of the bushing in relation to the earthed parts of the apparatus for which the bushing is foreseen (see 7.1).AS NZS 60137 pdf download.