问题 问答题 简答题

送电线路接地装置有哪些形式?

答案

参考答案:

(1)在土壤电阻率ρ≤lOOΩ•m的潮湿地区,接地电阻不超过lOΩ,即可利用杆塔基础、底盘拉盘等自然接地。

(2)在土壤电阻率lOOΩm<ρ≤300Ωm地区,应采用人工接地装置,接地体埋深应大于0.6~0.8m。

(3)在土壤电阻率300Ωm<ρ<2000Ωm的地区,应采用水平敷设的接地装置,埋深不小于0.5m。

(4)在土壤电阻率ρ>2000Ωm时,应采用6~8根总长度不超过500m放射形接地体或连续伸长接地体,埋深不小于0.3m。

(5)居民区或水田中的接地装置,宜围绕杆塔基础敷设。

(6)在高土壤电阻率的地区,如在杆塔附近有土壤电阻率较低的地带,可采用引外接地或其他措施。

改错题

第一节 短文改错(共10小题;每小题1分,满分10分)

以下标有题号的每一行均有一个错误,请找出,并按下列情况改正;此行多一个词;把多余的词用斜线(\)划掉,在该行右边横线上写出该词,并也用斜线划掉。此行缺一个词;在缺词处加一个漏字符号(^),在该行右边横线上写出该加的词。此行错一词;在错的词下划一横线,在该行右边横线上写出改正后的词。

注意:请在答题卡上作答。

Bill enjoyed shoot very much, but he was never good                  76.      

at it. One day his friend was named Jack visited his house                    77.      

and saw a new target Bill had put several days ago in his                      78.      

garden. Jack went nearer but saw a hole in the middle of                     79.      

the target. When jack asked who had shot at it. Bill said                       80.      

he had. “How far away are you? Two feet?” But Bill said                     81.      

he was 50 yards away. Then Bill’s wife explained Jack the                   82.      

hole. He said, “Bill went to a shop and bought a piece                         83.      

of wood. He put it in the garden and shot at it from 50 yard                 84.      

away, only to shoot a hole. Then he drew a target round a hole.”           85.      

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