问题 问答题 简答题

KZDF型隔爆型馈电开关使用前如何试验和整定。

答案

参考答案:

KZDF型馈电开关在安装使用前应对其性能进行试验和整定,具体方法如下:(1)馈电开关接入1140伏或660伏电源,将控制电源开关搬到“开”位置。接通控制电源,绿色的电源指示灯应发光。旋转“电动分合”开关至“合闸”位置,断路器应可靠合闸,“合闸”指示灯应发亮,旋至“分闸”位置,断路器应立即跳闸,指示灯熄灭。在合闸状态下掀起“手动分闸”按钮,断路器也应可靠分闸。无论是在电动分闸或手动分闸后,都不应有自动重合闸现象发生。(2)保护试验:在断路器合闸状态下,旋“过载试验”开关至试验位置,断路器应跳闸,红色“过载”指标灯应发光;旋至“复位”时,指示灯应熄灭,表明过载及短路保护性能完好。在断路器分闸状态下,旋转“漏电试验”开关至试验位置,黄色“漏电”指示灯应发光;旋至“复位”,指示灯应熄灭,表明漏电保护工作正常。将检漏继电器接入馈电开关负荷侧,在断路器合闸状态下,利用检漏继电器动作使馈电开关跳闸,经5~15秒钟后,馈电开关应自动重合闸,表明自复电功能正常。(3)保护整定:打开馈电开关前门,调整设在保护插件箱上的“过载整定”开关,按实际要求设定在200A、300A、400A或500A位置上即可。调整“短路整定”电位器,根据实际要求,设定在所需值上即可,短路整定电位器为一带刻度的线性精密电位器,刻度与短路动作电流之间关系如表所示。

阅读理解
阅读理解。
     Here is a page from a magazine called Future. Read the following information about things that may
happen in ten years.
     Cars will run on solar power (太阳能) and will be much cleaner. They will be much safer. For example,
if you are too close to another car or if you are driving dangerously, your car will slow down or stop by
itself.
     New cities will have to be built in the sea. Some cities on water will have two levels (层). People will live
on the upper level; the lower level will be used for traffic, shops and factories.
     Biotechnology (生物技术) will make food better and healthier. Plants without insects or illnesses (病虫害)
will be developed. The taste of fruit and vegetables will be better and food will be kept longer.
     Many new ways to cure (治愈) illnesses will be found. People will use products of genetic engineering
(基因产品) to cure more illnesses. However, some new illnesses will appear.
1. What will happen in the future according to the passage?

[ ]

A. The air won't be much cleaner.
B. Cars will run by itself without a driver.
C. It'll be much more dangerous to drive a car.
D. There'll be fewer accidents and less pollution (污染).
2. Where will new cities have to be built in the future?

[ ]

A. In the sea.
B. In the sky.
C. Underground.
D. On the land.
3. What will be made better and healthier by biotechnology?

[ ]

A. Medicine.
B. Toys.
C. Food.
D. Clothes.
4. Genetic engineering will help doctors to cure more ______.

[ ]

A. cold
B. illnesses
C. cancer
D. headache
5. Which is the best title (标题) of the passage?

[ ]

A. Cars in the future.
B. Get ready for the future.
C. How to keep food longer?
D. Where will people live in the future?
多项选择题