break down voltage （绝缘套管）是什么意思？
请教各位前辈：绝缘热缩套管、玻璃纤维管的技术参数除了额定工作电压之外，break down voltage 是什么意思？谢谢！ 出故障电压 break down voltage：击穿电压，任何介质材料都有他的击穿电压值，它同样是评价一种材料介电性能的一个指标 如果使用绝缘热缩套管、玻璃纤维管作为双重绝缘，标准（如60950等）对break down voltage有什么样的要求？ 一般情况下，产品要求中不会涉及到这个材料本身的基本指标。只要满足产品的绝缘电阻，漏电流和耐压测试就可以了 个人认为:可以通过绝缘电阻测试,漏电流测试,耐电压测试来确定以上测试项目,
相关标准为测试依据. 引用第2楼cableyzf于2007-10-23 11:26发表的:
break down voltage：击穿电压，任何介质材料都有他的击穿电压值，它同样是评价一种材料介电性能的一个指标
请问：
break down voltage：击穿电压与
dielectric strength：介电强度-----测试是不是一样的方法？ General speaking, break down voltage is the voltage that the insulation cannot maintain its resistance after the voltage you applied to the insulation.
This means that the insulation resistance will be lost to very small value. UL 224 是绝缘套管标准，其5.6条款对击穿电压和测试方法有明确要求。
5.6 Dielectric voltage withstand and breakdown
5.6.1 Aged and unaged tubing shall be capable of withstanding, without breakdown, the application of a 60 Hz essentially sinusoidal potential of 2500 V applied for a period of 1 minute between a conductor or conductors inserted in the tubing and strip metal foil wrapped around the outer surface of the tubing. Thepotential shall then be increased until breakdown occurs. The breakdown potential of tubing that has been aged as indicated in Item 9 of Tables 7 to 32 or after 7 days at the temperature determined from the formula in Clause 5.3.7.9, as applicable, shall be at least 50 percent of the breakdown potential of the
unaged tubing, but not less than 2500 V.
5.6.2 Three specimens of tubing, each 460 mm (18 in) in length, shall be aged in a circulating-air oven as indicated in Item 9 of Tables 7 to 32 or after 7 days at the temperature determined from the formula
in Clause 5.3.7.9, as applicable, and shall then be cooled to room temperature. These and similar specimens conditioned for the same length of time at a temperature of 23.0 ±2.0 °C (73.4 ±3.6°F) shall
be tested. One clean, straight, bare, solid, copper conductor shall be inserted with a snug fit into each specimen of 0.305 to 3.88 mm (0.012 to 0.153 in) tubing prior to aging. Several conductors shall be
inserted with a snug fit into 3.89 mm (0.154 in) inside diameter or larger tubing. Heat-shrinkable tubing shall be centred and recovered on a conductor or conductors having the same overall diameter as the
maximum recovered inside diameter of the tubing being tested (including adhesive for tubing with meltable liner, as specified by the manufacturer). The centre 152 mm (6 in) portion of each specimen shall be
wrapped with strip metal foil.
5.6.3 Each specimen shall be stressed by means of a testing transformer whose output potential is continuously monitored by an acceptable voltmeter that is connected in the output circuit and directly and
precisely indicates the potential being applied to a specimen, is essentially sinusoidal at 50 to 60 Hz, and can be varied continuously from 0 to at least 2500 V. The applied potential shall be increased from zero at an essentially uniform rate that is not less than 100 percent of the voltage rating for the product in 60 seconds, and not more than 100 percent in 10 seconds (the rate of increase shall not exceed 500 V/s in any case). The increase shall continue in this manner until the voltage reaches 2500 V. If this level is reached without breakdown, the potential shall be held constant at 2500 V for 60 seconds and shall then
be increased at the rate mentioned above until breakdown occurs.
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