导体热稳定计算值.pptx

导体热稳定计算值

式中：I→最大短路电流，A；S→导体或屏蔽截面，mm2；ε→1.0导体；1.2金属屏蔽；K=226（铜）；β=234（铜）；αf=短路允许最高温度，℃；αi=短路前温度，℃；t=短路时间，S。导体热稳定计算书：下表所列的导体和金属屏蔽热稳定计算值是根据下述公式计算的：导体热稳定计算书（导体热稳定计算、金属屏蔽热稳定计算）对短路持续时间在0.2～5S的各种情况，最大允许短路电流可按下式计算：式中：Ik－短路时间为tk的最大允许短路电流，AI1－短路时间为1S的最大容许短路电流，Atk－短路时间，S

XLPE绝缘导体热稳定计算值单位：kA/1秒截面mm2铜导体短路前温度℃3550658090101.731.71.61.51.4162.772.642.52.42.3254.334.23.93.83.7356.065.85.55.35.2508.78.37.87.47.27012.111.611.010.410.09516.515.714.914.113.612020.819.818.817.817.215026.024.823.522.321.518532.030.529.027.526.524041.639.637.635.734.530052.049.547.144.959.840069.366.062.643.157.4注：θf=250℃截面mm2铜导体短路前温度℃3550702.50.350.320.2960.840.780.69101.41.291.15162.232.071.84253.493.232.88354.894.534.03506.986.475.8709.779.058.19513.2612.2810.912016.7515.5213.815020.9419.4017.318525.8323.9221.324033.5131.0327.6230041.8838.7934.5340055.8551.7246.0450069.8164.6657.54注：θf=160℃PVC绝缘导体热稳定计算值单位：kA/1秒