电线额定承载电流估算口诀
<br/>个人觉得不错的东西,适合初学者 是的，我下来看了，满好的 <p>谢了</p><p> </p> 能看看吗 <p>顶</p> <p>感谢</p> 下了，看了，很不错，说的很细 记在脑子里 <span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">一般铜线安全计算方法是：<span lang="EN-US"> <br/>2.5</span>平方毫米铜电源线的安全载流量－－<?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /><st1:chmetcnv w:st="on" unitname="a" sourcevalue="28" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">28A</span></st1:chmetcnv>。<span lang="EN-US"> <br/>4</span>平方毫米铜电源线的安全载流量－－<st1:chmetcnv w:st="on" unitname="a" sourcevalue="35" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">35A</span></st1:chmetcnv><span lang="EN-US"> </span>。<span lang="EN-US"> <br/>6</span>平方毫米铜电源线的安全载流量－－<st1:chmetcnv w:st="on" unitname="a" sourcevalue="48" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">48A</span></st1:chmetcnv><span lang="EN-US"> </span>。<span lang="EN-US"> <br/>10</span>平方毫米铜电源线的安全载流量－－<st1:chmetcnv w:st="on" unitname="a" sourcevalue="65" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">65A</span></st1:chmetcnv>。<span lang="EN-US"> <br/>16</span>平方毫米铜电源线的安全载流量－－<st1:chmetcnv w:st="on" unitname="a" sourcevalue="91" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">91A</span></st1:chmetcnv><span lang="EN-US"> </span>。<span lang="EN-US"> <br/>25</span>平方毫米铜电源线的安全载流量－－<st1:chmetcnv w:st="on" unitname="a" sourcevalue="120" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">120A</span></st1:chmetcnv>。<span lang="EN-US"> <br/><br/><br/></span></span><span style="FONT-SIZE: 13.5pt; COLOR: #003366; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">如果是铝线，线径要取铜线的<span lang="EN-US">1.5-2</span>倍。 </span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/></span><span style="FONT-SIZE: 13.5pt; COLOR: #003366; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">如果铜线电流小于<st1:chmetcnv w:st="on" unitname="a" sourcevalue="28" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">28A</span></st1:chmetcnv>，按每平方毫米<st1:chmetcnv w:st="on" unitname="a" sourcevalue="10" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">10A</span></st1:chmetcnv>来取肯定安全。 </span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/></span><span style="FONT-SIZE: 13.5pt; COLOR: #003366; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">如果铜线电流大于<st1:chmetcnv w:st="on" unitname="a" sourcevalue="120" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">120A</span></st1:chmetcnv>，按每平方毫米<st1:chmetcnv w:st="on" unitname="a" sourcevalue="5" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">5A</span></st1:chmetcnv>来取。</span><span style="FONT-SIZE: 13.5pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"> </span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/></span><span style="FONT-SIZE: 13.5pt; COLOR: #003366; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">导线的截面积所能正常通过的电流可根据其所需要导通的电流总数进行选择，一般可按照如下顺口溜进行确定：</span><span style="FONT-SIZE: 13.5pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"> </span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/></span><span style="FONT-SIZE: 13.5pt; COLOR: #003366; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">十下五<span lang="EN-US">,</span>百上二<span lang="EN-US">, </span>二五三五四三界<span lang="EN-US">,</span>柒拾玖五两倍半<span lang="EN-US">,</span>铜线升级算<span lang="EN-US">. </span></span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/></span><span style="FONT-SIZE: 13.5pt; COLOR: #003366; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">给你解释一下<span lang="EN-US">,</span>就是<span lang="EN-US">10</span>平方一下的铝线<span lang="EN-US">,</span>平方毫米数乘以<span lang="EN-US">5</span>就可以了<span lang="EN-US">,</span>要是铜线呢<span lang="EN-US">,</span>就升一个档<span lang="EN-US">,</span>比如<span lang="EN-US">2.5</span>平方的铜线<span lang="EN-US">,</span>就按<span lang="EN-US">4</span>平方计算<span lang="EN-US">.</span>一百以上的都是截面积乘以<span lang="EN-US">2, </span>二十五平方以下的乘以<span lang="EN-US">4, </span>三十五平方以上的乘以<span lang="EN-US">3, </span>柒拾和<span lang="EN-US">95</span>平方都乘以<span lang="EN-US">2.5,</span>这么几句口诀应该很好记吧<span lang="EN-US">, </span></span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/></span><span style="FONT-SIZE: 13.5pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">说明<span lang="EN-US">:</span>只能作为估算<span lang="EN-US">,</span>不是很准确。<span lang="EN-US"> <br/></span>另外如果按室内记住电线<span lang="EN-US">6</span>平方毫米以下的铜线，每平方电流不超过<st1:chmetcnv w:st="on" unitname="a" sourcevalue="10" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">10A</span></st1:chmetcnv>就是安全的，从这个角度讲，你可以选择<span lang="EN-US">1.5</span>平方的铜线或<span lang="EN-US">2.5</span>平方的铝线。<span lang="EN-US"> <br/><st1:chmetcnv w:st="on" unitname="米" sourcevalue="10" hasspace="False" negative="False" numbertype="1" tcsc="0">10<span lang="EN-US"><span lang="EN-US">米</span></span></st1:chmetcnv><span lang="EN-US">内，导线电流密度<st1:chmetcnv w:st="on" unitname="a" sourcevalue="6" hasspace="False" negative="False" numbertype="1" tcsc="0">6A</st1:chmetcnv>/</span></span>平方毫米比较合适，<span lang="EN-US">10<st1:chmetcnv w:st="on" unitname="米" sourcevalue="50" hasspace="False" negative="True" numbertype="1" tcsc="0">-50<span lang="EN-US"><span lang="EN-US">米</span></span></st1:chmetcnv><span lang="EN-US">，<st1:chmetcnv w:st="on" unitname="a" sourcevalue="3" hasspace="False" negative="False" numbertype="1" tcsc="0">3A</st1:chmetcnv>/</span></span>平方毫米<span lang="EN-US">,50<st1:chmetcnv w:st="on" unitname="米" sourcevalue="200" hasspace="False" negative="True" numbertype="1" tcsc="0">-200<span lang="EN-US"><span lang="EN-US">米</span></span></st1:chmetcnv><span lang="EN-US">，<st1:chmetcnv w:st="on" unitname="a" sourcevalue="2" hasspace="False" negative="False" numbertype="1" tcsc="0">2A</st1:chmetcnv>/</span></span>平方毫米，<st1:chmetcnv w:st="on" unitname="米" sourcevalue="500" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">500</span>米</st1:chmetcnv>以上要小于<st1:chmetcnv w:st="on" unitname="a" sourcevalue="1" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">1A</span></st1:chmetcnv><span lang="EN-US">/</span>平方毫米。从这个角度，如果不是很远的情况下，你可以选择<span lang="EN-US">4</span>平方铜线或者<span lang="EN-US">6</span>平方铝线。<span lang="EN-US"> <br/></span>如果真是距离<st1:chmetcnv w:st="on" unitname="米" sourcevalue="150" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">150</span>米</st1:chmetcnv>供电（不说是不是高楼），一定采用<span lang="EN-US">4</span>平方的铜线。</span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/><br/><br/></span><span style="FONT-SIZE: 13.5pt; COLOR: purple; FONT-FAMILY: 幼圆; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-hansi-font-family: 宋体">导线的阻抗与其长度成正比，与其线径成反比。请在使用电源时，特别注意输入与输出导线的线材与线径问题。以防止电流过大使导线过热而造成事故。 </span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/></span><span style="FONT-SIZE: 13.5pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">导线线径一般按如下公式计算：<span lang="EN-US"> <br/></span>铜线：<span lang="EN-US"> S= IL / 54.4*U` <br/></span>铝线：<span lang="EN-US"> S= IL / 34*U` <br/></span>式中：<span lang="EN-US">I——</span>导线中通过的最大电流（<span lang="EN-US">A</span>）<span lang="EN-US"> <br/>L——</span>导线的长度（<span lang="EN-US">M</span>）<span lang="EN-US"> <br/>U`——</span>充许的电源降（<span lang="EN-US">V</span>）<span lang="EN-US"> <br/>S——</span>导线的截面积（<span lang="EN-US">MM2</span>）<span lang="EN-US"> <br/></span>说明：<span lang="EN-US"> <br/>1</span>、<span lang="EN-US">U`</span>电压降可由整个系统中所用的设备（如探测器）范围分给系统供电用的电源电压额定值综合起来考虑选用。<span lang="EN-US"> <br/>2</span>、计算出来的截面积往上靠<span lang="EN-US">.</span></span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/><br/><br/></span><span style="FONT-SIZE: 13.5pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">绝缘导线载流量估算<span lang="EN-US"> <br/></span>铝芯绝缘导线载流量与截面的倍数关系<span lang="EN-US"> <br/></span>导线截面<span lang="EN-US">(mm 2 ) </span> <span lang="EN-US">1</span> <span lang="EN-US">1</span>．<span lang="EN-US">5</span> <span lang="EN-US">2</span>．<span lang="EN-US">5</span> <span lang="EN-US">4</span> <span lang="EN-US">6</span> <span lang="EN-US">10</span> <span lang="EN-US">16</span> <span lang="EN-US">25</span> <span lang="EN-US">35</span> <span lang="EN-US">50</span> <span lang="EN-US">70</span> <span lang="EN-US"> 95</span> <span lang="EN-US"> 120 <br/></span>载流是截面倍数<span lang="EN-US"> 9 8 7 6 5 4 3</span>．<span lang="EN-US">5 3 2</span>．<span lang="EN-US">5 <br/></span>载流量<span lang="EN-US">(A) 9 14 23 32 48 60 90 100 123 150 210 238 300 <br/></span>估算口诀：二点五下乘以九，往上减一顺号走。三十五乘三点五，双双成组减点五。条件有变加折算，高温九折铜升级。穿管根数二三四，八七六折满载流。 说明：<span lang="EN-US">(1)</span>本节口诀对各种绝缘线<span lang="EN-US">(</span>橡皮和塑料绝缘线<span lang="EN-US">)</span>的载流量<span lang="EN-US">(</span>安全电流<span lang="EN-US">)</span>不是直接指出，而是<span lang="EN-US">“</span>截面乘上一定的倍数<span lang="EN-US">”</span>来表示，通过心算而得。由表<span lang="EN-US">5 3</span>可以看出：倍数随截面的增大而减小。<span lang="EN-US">“</span>二点五下乘以九，往上减一顺号走<span lang="EN-US">”</span>说的是<span lang="EN-US">2</span>．<st1:chmetcnv w:st="on" unitname="mm" sourcevalue="5" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">5mm</span></st1:chmetcnv><span lang="EN-US">’</span>及以下的各种截面铝芯绝缘线，其载流量约为截面数的<span lang="EN-US">9</span>倍。如<span lang="EN-US">2</span>．<st1:chmetcnv w:st="on" unitname="mm" sourcevalue="5" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">5mm</span></st1:chmetcnv><span lang="EN-US">’</span>导线，载流量为<span lang="EN-US">2</span>．<span lang="EN-US">5×9</span>＝<span lang="EN-US">22</span>．<span lang="EN-US">5(A)</span>。从<st1:chmetcnv w:st="on" unitname="mm" sourcevalue="4" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">4mm</span></st1:chmetcnv><span lang="EN-US">’</span>及以上导线的载流量和截面数的倍数关系是顺着线号往上排，倍数逐次减<span lang="EN-US">l</span>，即<span lang="EN-US">4×8</span>、<span lang="EN-US">6×7</span>、<span lang="EN-US">10×6</span>、<span lang="EN-US">16×5</span>、<span lang="EN-US">25×4</span>。<span lang="EN-US">“</span>三十五乘三点五，双双成组减点五<span lang="EN-US">”</span>，说的是<st1:chmetcnv w:st="on" unitname="mm" sourcevalue="35" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">35mm</span></st1:chmetcnv><span lang="EN-US">”</span>的导线载流量为截面数的<span lang="EN-US">3</span>．<span lang="EN-US">5</span>倍，即<span lang="EN-US">35×3</span>．<span lang="EN-US">5</span>＝<span lang="EN-US">122</span>．<span lang="EN-US">5(A)</span>。从<st1:chmetcnv w:st="on" unitname="mm" sourcevalue="50" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">50mm</span></st1:chmetcnv><span lang="EN-US">’</span>及以上的导线，其载流量与截面数之间的倍数关系变为两个两个线号成一组，倍数依次减<span lang="EN-US">0</span>．<span lang="EN-US">5</span>。即<span lang="EN-US">50</span>、<span lang="EN-US">70mm’</span>导线的载流量为截面数的<span lang="EN-US">3</span>倍；<span lang="EN-US">95</span>、<span lang="EN-US">120mm”</span>导线载流量是其截面积数的<span lang="EN-US">2</span>．<span lang="EN-US">5</span>倍，依次类推。<span lang="EN-US">“</span>条件有变加折算，高温九折铜升级<span lang="EN-US">”</span>。上述口诀是铝芯绝缘线、明敷在环境温度<st1:chmetcnv w:st="on" unitname="℃" sourcevalue="25" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">25℃</span></st1:chmetcnv>的条件下而定的。若铝芯绝缘线明敷在环境温度长期高于<st1:chmetcnv w:st="on" unitname="℃" sourcevalue="25" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">25℃</span></st1:chmetcnv>的地区，导线载流量可按上述口诀计算方法算出，然后再打九折即可；当使用的不是铝线而是铜芯绝缘线，它的载流量要比同规格铝线略大一些，可按上述口诀方法算出比铝线加大一个线号的载流量。如<st1:chmetcnv w:st="on" unitname="mm" sourcevalue="16" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">16mm</span></st1:chmetcnv><span lang="EN-US">’</span>铜线的载流量，可按<st1:chmetcnv w:st="on" unitname="mm" sourcevalue="25" hasspace="False" negative="False" numbertype="1" tcsc="0"><span lang="EN-US">25mm</span></st1:chmetcnv><span lang="EN-US">2</span>铝线计算。<span lang="EN-US"> <br/></span>铜线每平方毫米<span lang="EN-US">6</span>安培。铝线是每平方毫米<span lang="EN-US">5</span>安培<span lang="EN-US">(</span>仅供快速估算<span lang="EN-US">) <br/>4</span>平方的铜线：<span lang="EN-US">4*6=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="24" hasspace="False" negative="False" numbertype="1" tcsc="0">24A</st1:chmetcnv> <br/>6</span>平方的铜线：<span lang="EN-US">6*6=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="36" hasspace="False" negative="False" numbertype="1" tcsc="0">36A</st1:chmetcnv> <br/>10</span>平方的铜线：<span lang="EN-US">10*6=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="60" hasspace="False" negative="False" numbertype="1" tcsc="0">60A</st1:chmetcnv> <br/>16</span>平方的铜线：<span lang="EN-US">16*6=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="96" hasspace="False" negative="False" numbertype="1" tcsc="0">96A</st1:chmetcnv> <br/></span></span><span lang="EN-US" style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA"><br/>4</span><span style="FONT-SIZE: 10pt; FONT-FAMILY: 宋体; mso-bidi-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">平方的铝线：<span lang="EN-US">4*5=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="20" hasspace="False" negative="False" numbertype="1" tcsc="0">20A</st1:chmetcnv> <br/>6</span>平方的铝线：<span lang="EN-US">6*5=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="30" hasspace="False" negative="False" numbertype="1" tcsc="0">30A</st1:chmetcnv> <br/>10</span>平方的铝线：<span lang="EN-US">10*5=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="0" hasspace="False" negative="False" numbertype="1" tcsc="0">00A</st1:chmetcnv> <br/>16</span>平方的铝线：<span lang="EN-US">16*5=<st1:chmetcnv w:st="on" unitname="a" sourcevalue="90" hasspace="False" negative="False" numbertype="1" tcsc="0">90A</st1:chmetcnv> <br/><br/></span></span> 已知变压器容量，求其各电压等级侧额定电流<span lang="EN-US"> <br/></span>口诀<span lang="EN-US"> a </span>：<span lang="EN-US"> <br/></span>容量除以电压值，其商乘六除以十。<span lang="EN-US"> <br/></span>说明：适用于任何电压等级。<span lang="EN-US"> <br/></span>在日常工作中，有些电工只涉及一两种电压等级的变压器额定电流的计算。将以上口诀简化，则可推导出计算各电压等级侧额定电流的口诀：<span lang="EN-US"> <br/></span>容量系数相乘求。<span lang="EN-US"> <br/><br/></span>已知变压器容量，速算其一、二次保护熔断体（俗称保险丝）的电流值。<span lang="EN-US"> <br/></span>口诀<span lang="EN-US"> b </span>：<span lang="EN-US"> <br/></span>配变高压熔断体，容量电压相比求。<span lang="EN-US"> <br/></span>配变低压熔断体，容量乘<span lang="EN-US">9</span>除以<span lang="EN-US">5</span>。<span lang="EN-US"> <br/></span>说明：<span lang="EN-US"> <br/></span>正确选用熔断体对变压器的安全运行关系极大。当仅用熔断器作变压器高、低压侧保护时，熔体的正确选用更为重要。这是电工经常碰到和要解决的问题。<span lang="EN-US"> <br/><br/></span>已知三相电动机容量，求其额定电流<span lang="EN-US"> <br/></span>口诀（<span lang="EN-US">c</span>）：容量除以千伏数，商乘系数点七六。<span lang="EN-US"> <br/></span>说明：<span lang="EN-US"> <br/></span>（<span lang="EN-US">1</span>）口诀适用于任何电压等级的三相电动机额定电流计算。由公式及口诀均可说明容量相同的电压等级不同的电动机的额定电流是不相同的，即电压千伏数不一样，去除以相同的容量，所得<span lang="EN-US">"</span>商数<span lang="EN-US">"</span>显然不相同，不相同的商数去乘相同的系数<span lang="EN-US">0.76</span>，所得的电流值也不相同。若把以上口诀叫做通用口诀，则可推导出计算<span lang="EN-US">220</span>、<span lang="EN-US">380</span>、<span lang="EN-US">660</span>、<span lang="EN-US">3.6kV</span>电压等级电动机的额定电流专用计算口诀，用专用计算口诀计算某台三相电动机额定电流时，容量千瓦与电流安培关系直接倍数化，省去了容量除以千伏数，商数再乘系数<span lang="EN-US">0.76</span>。<span lang="EN-US"> <br/></span>三相二百二电机，千瓦三点五安培。<span lang="EN-US"> <br/></span>常用三百八电机，一个千瓦两安培。<span lang="EN-US"> <br/></span>低压六百六电机，千瓦一点二安培。<span lang="EN-US"> <br/></span>高压三千伏电机，四个千瓦一安培。<span lang="EN-US"> <br/></span>高压六千伏电机，八个千瓦一安培。<span lang="EN-US"> <br/></span>（<span lang="EN-US">2</span>）口诀<span lang="EN-US">c </span>使用时，容量单位为<span lang="EN-US">kW</span>，电压单位为<span lang="EN-US">kV</span>，电流单位为<span lang="EN-US">A</span>，此点一定要注意。<span lang="EN-US"> <br/></span>（<span lang="EN-US">3</span>）口诀<span lang="EN-US">c </span>中系数<span lang="EN-US">0.76</span>是考虑电动机功率因数和效率等计算而得的综合值。功率因数为<span lang="EN-US">0.85</span>，效率不<span lang="EN-US">0.9</span>，此两个数值比较适用于几十千瓦以上的电动机，对常用的<span lang="EN-US">10kW</span>以下电动机则显得大些。这就得使用口诀<span lang="EN-US">c</span>计算出的电动机额定电流与电动机铭牌上标注的数值有误差，此误差对<span lang="EN-US">10kW</span>以下电动机按额定电流先开关、接触器、导线等影响很小。<span lang="EN-US"> <br/></span>（<span lang="EN-US">4</span>）运用口诀计算技巧。用口诀计算常用<span lang="EN-US">380V</span>电动机额定电流时，先用电动机配接电源电压<span lang="EN-US">0.38kV</span>数去除<span lang="EN-US">0.76</span>、商数<span lang="EN-US">2</span>去乘容量（<span lang="EN-US">kW</span>）数。若遇容量较大的<span lang="EN-US">6kV</span>电动机，容量<span lang="EN-US">kW</span>数又恰是<span lang="EN-US">6kV</span>数的倍数，则容量除以千伏数，商数乘以<span lang="EN-US">0.76</span>系数。<span lang="EN-US"> <br/></span>（<span lang="EN-US">5</span>）误差。由口诀<span lang="EN-US">c </span>中系数<span lang="EN-US">0.76</span>是取电动机功率因数为<span lang="EN-US">0.85</span>、效率为<span lang="EN-US">0.9</span>而算得，这样计算不同功率因数、效率的电动机额定电流就存在误差。由口诀<span lang="EN-US">c </span>推导出的<span lang="EN-US">5</span>个专用口诀，容量（<span lang="EN-US">kW</span>）与电流（<span lang="EN-US">A</span>）的倍数，则是各电压等级（<span lang="EN-US">kV</span>）数除去<span lang="EN-US">0.76</span>系数的商。专用口诀简便易心算，但应注意其误差会增大。一般千瓦数较大的，算得的电流比铭牌上的略大些；而千瓦数较小的，算得的电流则比铭牌上的略小些。对此，在计算电流时，当电流达十多安或几十安时，则不必算到小数点以后。可以四舍而五不入，只取整数，这样既简单又不影响实用。对于较小的电流也只要算到一位小数即可 太多看不完 顶个 <p>积分不够，继续努力</p> 11楼。12楼赞一个 <p>谢谢,有用的东西</p>
<p> </p> 积分不够，继续努力 分数不够，努力中 11 12楼 是好人………………………… <p>dingqi </p> 分不够呀，谢谢了！