单芯电子线容许电流计算谁知道?
最新回答 (3条回答)
单芯电子线容许电流计算: 单芯容许电流式(General formula for single insulation): I1 =√(Tc-Ta)/r*Rth Tc:表示额定温度(Temperature rating) Ta:表示测试环境温度(Ambient temperature test) r:表示导体电阻 (Conductor resistance)Ω/CM 铜导体电阻计算式(Copper Conductor resistance formula) r=r0{1+0.00393(Tc –20℃)} r0:为20℃时导体电阻 Rth:全热电阻(high heat resistance)(℃.Ω/CM) Rth=R1+R2 R1:表示绝缘体热电阻(Insulator heat resistance) R1=ρ1/2π*loge(d2/d1) ρ 1:为绝缘体固有热电阻(Insulator inherent heat resistance), PVC绝缘体的固有热电阻为500(PVC insulator inherent heat resistance 500)(℃.Ω/CM) d1:导体绞合外径(Conductor stranding OD) d2:绝缘体外径(Insulator OD) R2:表面放散热电阻(Outside radiation heat resistance)(℃.Ω/CM) R2=10ρ2/πd2 ρ2:表面放散热电阻 (Outside radiation heat resistance)(℃.Ω/CM) ρ2=500+10d2 例:16AWG 65/0.16TD、 1007 PVC绝缘、线径为2.35mm电线(使用环境温度为20℃): (TD指镀锡铜) Tc=80℃ d1=1.5mm d2=2.35mm r0=13.7Ω/km(20℃) r0=13.7*10-5 (Ω/CM) r=r0*{1+0.00393(80℃–20℃)}* 10-5 =16.9*10-5 (Ω/CM) ρ0=600(℃.Ω/CM) ρ2=500+10*23.5(℃.Ω/CM)=523.5(℃.Ω/CM) R1=600/2π*loge(2.35/1.5)= 42.87 e=2.7183(常数) R2=(10*523.5)/(π*2.35)=709.1 单芯线容许流式(General formula for single insulation): I1 =√Tc-Ta/r*Rth=√(80-20)/16.9*10-5 *(42.87+709.1) = 21.7 A (当周围环境温度约为20℃) 例:16AWG 65/0.16TD、 1007 PVC绝缘、线径为2.35mm电线(使用环境温度为40℃): Tc=80℃ d1=1.5mm d2=2.35mm r0=14.9Ω/km(20℃) r0=13.7*10-5 (Ω/CM) r=r0*{1+0.00393(80℃–20℃)}* 10-5 =18.4*10-5 (Ω/CM) ρ0=600(℃.Ω/CM)
Rth=R1+R2
R1:表示绝缘体热电阻 R1=ρ1/2π*loge(d2/d1
R2:表面放散热电阻
R2=10ρ2/πd2
ρ2=500+10d2
单芯电子线容许电流计算:单芯容许电流式(Generalformulafo;I1=√TTRth;Tc:表示额定温度(Temperaturerat;r=r0{1+0.00393(Tc–20℃)}r;Rth:全热电阻(highheatresista;1:为绝缘体固有热电阻(Insulatorinh;PVC绝缘体的固有热电阻为500(PVCinsu;d1:导体绞合
单芯电子线容许电流计算:
单芯容许电流式(General formula for single insulation):
I1 =√TTRth
Tc:表示额定温度(Temperature rating) Ta:表示测试环境温度(Ambient temperature test) r:表示导体电阻 (Conductor resistance)Ω/CM 铜导体电阻计算式(Copper Conductor resistance formula)
r=r0{1+0.00393(Tc –20℃)} r0:为20℃时导体电阻
Rth:全热电阻(high heat resistance)(℃.Ω/CM) Rth=R1+R2 R1:表示绝缘体热电阻(Insulator heat resistance) R1=ρ1/2π*loge(d2/d1) ρ
1:为绝缘体固有热电阻(Insulator inherent heat resistance),
PVC绝缘体的固有热电阻为500(PVC insulator inherent heat resistance 500)(℃.Ω/CM)
d1:导体绞合外径(Conductor stranding OD) d2:绝缘体外径(Insulator OD) R2:表面放散热电阻(Outside radiation heat resistance)(℃.Ω/CM) R2=10ρ2/πd2
ρ2:表面放散热电阻 (Outside radiation heat resistance)(℃.Ω/CM) ρ2=500+10d2