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标题: [求助]麻烦帮我算算需要多少平方的电缆 [查看完整版帖子] [打印本页]
时间: 2008-1-24 16:20
作者: congooo
标题: [求助]麻烦帮我算算需要多少平方的电缆
<p> 从电力室拉线到一个机架，距离大概是70米，一个回路就是140米了，大概20A的电流，我知道有个公式</p><p>S=I*L/57/U</p><p>电池室的蓄电池——电力室的直流分配柜——机架</p><p>就是电压降不知道该取多少，麻烦大家帮帮忙！</p><p></p>
[此贴子已经被作者于2008-1-24 16:20:44编辑过]
时间: 2008-1-24 16:44
作者: clarent0210
<p>给你一个<span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;"><strong>导体电阻率的口诀：</strong></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 180%; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto;"><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">导体材料电阻率，欧姆毫方每一米，（</span><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;"> </span><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">长</span><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">1</span><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">米，截面积</span><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">1</span><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">平方毫米导体的电阻值，摄氏温度为</span><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">20）</span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 180%; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto;"><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;"> </span><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">铜铝铁碳依次排，从小到大不用愁。</span><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;"><p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 180%; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto;"><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;"> </span><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">扩大万倍来记数，铜的最小一七五，</span><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;"><p></p></span></p><p class="MsoNormal" align="left" style="MARGIN: 0cm 0cm 0pt; WORD-BREAK: break-all; LINE-HEIGHT: 180%; TEXT-ALIGN: left; mso-pagination: widow-orphan; mso-margin-top-alt: auto; mso-margin-bottom-alt: auto;"><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;"> </span><span style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;">铝的数值二八三，整整一千纯铁数，</span><span lang="EN-US" style="FONT-SIZE: 9pt; LINE-HEIGHT: 180%; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-font-kerning: 0pt;"><p></p></span></p><p><span lang="EN-US" style="FONT-SIZE: 9pt; FONT-FAMILY: Verdana; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体;"> </span><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">碳的数值算最大，足足十万无零头。</span></p><p><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;">按照这个口诀计算，1米、1平方毫米铜的电阻是0.0175欧姆，自己计算一下就知道压降了</span></p><p><span style="FONT-SIZE: 9pt; FONT-FAMILY: 宋体; mso-ascii-font-family: Verdana; mso-hansi-font-family: Verdana; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA;"><strong></strong></span></p>
时间: 2008-1-25 10:25
作者: lnyuan66
<p>最大允许压降:U=3.2V 就取3.2V吧</p>
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