对断路器为什么要进行三相同时接触误差的测定具体有何规定？
参考答案：
保证三相触头或同柏双触头的同时接触误差在允许的误差限度内，是为了避免触头因三相不问财接触（或分离）而造成烧伤或引起触头间电弧重燃而发生操作过电压。同时接触误差的规定值为：（1）三相之间不同期接触误差不应超过2mm；（2）同相两触头不同期误差在35kV断路器上不应超过0.5mm。
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| What do people do with their old, out-of-date but still useful computers? 1 people don't know what to do with them. Many old computers are 2 in people's homes. Many more are simply thrown out with 3 . Finally, some 4 are thinking of ways to bring down 5 old computers. Sony has agreed to help 6 old Sony products. Dell and HP now also take back some old computers. In some countries, laws are being passed, too. Computer companies will have to pay for 7 and recycling their used products. And 8 of computer waste must be recycled. The 9 behind the laws is that computer companies themselves should pay the cost. That will encourage them 10 computers that are easier and cheaper to repair and upgrade (升级). Yet while many people are throwing away good computers, 11 cannot afford them at all. 12 organizations are working to solve this problem. They collect and repair old computers. Some also teach others how 13 computers. The computers then go to schools, charities and people who need them. 14 a used computer to one of these organizations can turn one person's rubbish into 15 useful thing and cut down waste, too. | ||||
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